S E R C ROYAL GREENWICH OBSERVATORY ISAAC NEWTON GROUP, LA PALMA Observatorio del Roque de los Muchachos del Instituto de Astrofisica de Canarias PEOPLES PHOTOMETER ACQUISITION SOFTWARE (PPAS) David Pike ADAM version 3 June 1987 CONTENTS Section Contents A PPAS Observation files B Observing modes C PPAS data files D On-line photometric results E Commands available within PPAS F Storing data on tape G Photometer apertures H The PPAS hardware file I Running ADAM and the PPAS J A typical observing setup K Connection file defaults L Controlling the telescope from within PPAS M Using the handset to interrupt data acquisition N Connection file (.CON) listings O Photomultiplier tube log Section A PPAS "Observation definition" files To obtain a photometric measurement of an object the photometer hardware set-up must be correct (the four pneumatic slide positions) and the integration time set. The PPAS programs derive the information necessary for this from a combination of ADAM variables and details given in the 'observation definition' (OD) files. There are up to three OD files operating at any one time. They are defined by a ROOT name (max 8 characters) and a file extension of either OBJ, SEQ or RUN. The first contains details of the objects (name, position, standard photometry if any), the second is the sequence file and defines a sequence of filters and integration times to be associated with the object. The third file allows a RUN name to be associated with a list of object names or other run names. The three files in use concurrently need not have the same root names. Different root names should be used liberally to distinguish between groups of objects, filter systems used in the sequences, etc. ADAM is informed of the root names to be used by the commands USEOBJ obj-root eg USEOBJ CDPOBJ will make CDPOBJ.OBJ the current object file USESEQ seq-root eg USESEQ FRED USERUN run-root eg USERUN DICK USEALL root will set all 3 OD files to the same root name The OD files themselves are created/appended to by use of the commands SETOBJ SETSEQ SETRUN They all act upon the currently-defined root and are described in more detail in section E. The OBJ file This file, created by SETOBJ, contains details of the objects to be observed. It is a formatted file with the format Object name RA DEC Equinox Standard photometry values 1X, A10 1X, A7, 1X, A7, 1X, F7.2 1X, 6F6.3 The photometric values can be used for on-line updating of zeropoints and extinction coefficients and in any case are useful for a comparison with the observed values. If the requested object name is not found in the current .OBJ file the acquisition program will search in a file of standard stars appropriate to the current photometric system and if not found there either with prompt the user for details of the object. In other words, if the object's position is not known beforehand and an object name which is not in the current .OBJ or standards file is requested, the object's details will be prompted for at run time and will automatically be stored in the .OBJ file. Note that this implies that even if no objects are to be entered before run time, the OBJ root must be defined. The SEQ file The sequence to be associated with an object is created by SETSEQ and held in the .SEQ file. This is a text file and has a typical entry of SEQ1 = U-U-10: B-B-10: V-V-5: R-R-2: I-I-5: SEQ2 = U-U-30: B-B-30: V-V-30: Here SEQ1 and SEQ2 are the names of the sequences which will be used to reference the filter-integration-time combinations. The names correspond to up to six combinations of Romeo and Juliet filter pairs and an integration time. Note that a sequence should not contain more than one measure with the same filter. For instance SEQ1 = U-U-10:U-U-5 would result in only the 5-second integration being stored although both integrations would be performed. The photometer software retains the concept of a "default sequence" name so that a specific sequence need not be entered for each object. The ADAM command DEFSEQ (parameter = sequence-name) sets up the default. Thus DEFSEQ SEQ1 will set SEQ1 as the default sequence and if an object is requested without qualification this sequence will be used for the observation. At run time, objects and sequences can be associated by a slash '/'. Thus OBJ1/SEQ1 explicitly requests OBJ1 to be observed with SEQ1. The RUN file For convenience in specifying the objects to be observed a RUN file (created by SETRUN) may be created. This associates a single run name with a list of objects (and their sequences) and/or other run names. An entry in the RUN file could thus be RUN1 = FRED/SEQ1, FRED, OBJ1, OBJ2 RUN2 = OBJ1/SEQ2, OBJ2, RUN1, FRED If, in an acquisition program, 'RUN2' is requested as the name to be observed, then RUN1 will be translated to its constituent objects and so the following objects will be observed OBJ1/SEQ2, OBJ2, FRED/SEQ1, FRED, OBJ1, OBJ2, FRED Those objects without an explicit declaration of the associated sequence will be observed with the default sequence. Aperture and mode slides Apart from the filter slides, the photometer contains a slide holding the apertures (diaphragms) and one containing optics to determine the mode of operation. This latter slide can hold things like the beam-splitter, star-sky prism and the Foster prism. Since the aperture and the mode settings change infrequently these are set according to the value of ADAM variables which themselves are set by the commands AP(ERTURE) and one of BS5050, BS9010, STRSKY, FOSTER. These should be set BEFORE running the acquisition program. Section B Observing Modes. The Peoples' Photometer is a dual channel instrument with a number of possible modes of operation. As detailed in the photometer manual, the photometer has four pneumatically controlled slides. Two contain the filters: one slide for each channel. A third slide contains the apertures and a fourth (the Mode slide) has three positions containing the field viewing mirror, the star-sky prism (which directs the light passing through the double apertures to the appropriate channels) and one of the beam splitters passing (nominally) either a 90:10 or 50:50 ratio of light to the two channels. For polarimetry mode the beam splitter is replaced by a FOSTER prism. The most common use of the photometer is in the double-aperture 2 channel mode, the so-called STARSKY mode. Normal observing procedure in this mode is to measure the object in one aperture while simultaneously recording a sky measure in the other channel. The object is then changed to the other aperture and the readings repeated. Two observations of each object are obtained, each with an accompanying sky measure. The command which controls this mode of observing is called PP22 (Peoples Photometer 2 Aperture 2 Star measure). Although this mode utilizes the two channels of the photometer there is no choice possible in the position of the sky measure - apart from a wholesale rotation of the A&G box turntable and this mode is therefore not suited to photometry in crowded fields. If the dual-channel nature of the normal observing mode is inappropriate - say because the sky measure cannot be obtained with the other channel owing to a crowded field - the photometer can revert to a single channel instrument under the control of command PP11. In this mode only data from the Romeo channel are used. The object and appropriate sky region must be measured separately and thus must be specified as separate and distinct 'object' names. An aperture plate with only one single aperture (in the Romeo beam) is used in this mode. It is also possible to configure the photometer for use in a number of other ways. These are described briefly below and the individual control programs are described in detail in Section E. Three modes are provided for observing in a continuous or semi-continuous fashion. Each of these modes has its own limitations and advantages. For observing in a relatively slow manner the program MON(ITOR) allows objects to be observed with integration times from 1 to 999 seconds in a semi-continuous way. The photometer setup is controlled as normal through the OD files but a separate command MONTIME is used to set the total monitoring time. The time specified in the sequence is taken as the integration time for each observation of the object. The main limitation of this method is the 'deadtime' between integrations (up to 2-3 seconds) which means the data are not contiguous. This mode produces data files in the normal format which may be used as input to LD and RAWPLOT. A better approximation to a truly continuous mode of operation is provided by the slow continuous (SLCONT) program. This uses the normal hardware setup and data are gathered in bursts on N seconds where N is the value set in the sequence. The time resolution (i.e. the individual data point integration time) is set by the command CONTRES. After each burst the user may quit the data acquisition or continue - after recentering the star, say. The time resolution should be between 250 and 1000 milliseconds for this mode. The data format produced has the same dimensions as the normal photometry files but each data record is used to store 43 data points, plus object identification and timing information. A summary of the data file can be produced using LSLCONT and the data plotted using PSLC(ONT). The final continuous mode (FCONT) requires some hardware modifications but allows truly continuous data, with time resolutions from 1-10000 millisecs, to be obtained. The limitations are that the total count in any one integration should not exceed 32767 (16 bits) and the count rate should not exceed 200KHz - this corresponds approximately to V = 8.0 on the JKT. To use this mode all the photometer setup must be done using individual commands (e.g. the filters, apertures, mode slide) and the total time and time resolution set using the commands CONTIME and CONTRES. Each integration of CONTIME seconds creates a new data file whose record length will depend on the amount of data being acquired. Polarimetry (both linear and circular) is catered for although it requires a change in the hardware set up. The specification of the required observation is very similar to that used in normal photometry but see the details given for the command POLAR. The scanning-slits configuration is a mode which uses a rotating slotted wheel to derive intensity profiles of images with approximately 13 msec time resolution. Every scan across the image gives 112 data bins each with an effective integration time of 119 nanosecs. This has been used so far to investigate the intensity profiles of close double stars. It requires a specific hardware configuration, see command SS for details. One can obtain an intensity profile of an object on a rather different spatial scale than is possible with the scanning slits using the STEP command. This interfaces the photometer to the telescope and allows the telescope to be stepped across an object between integrations. Plotting of the in-coming data is possible and this mode has been used to observe intensity profiles of galaxies and other extended objects. Summary of data acquisition commands PP11 - 'normal' 1-2 channel photometry PP22 MONITOR ) SLCONT ) - (semi-)continuous mode FCONT ) POLAR - polarimetry SS - scanning slits STEP - object profile by stepping aperture DEADTIME - acquire data to calculate PMT dead times See under the individual commands for further details and associated commands. Section C PPAS data files The data files produced by all the acquisition modes within PPAS can be treated as standard integer (I*4) data files and even though in some cases they contain both numerical and descriptor-type information they may be safely transferred to and from tape using the FITS programs. It is most important that the files produced by the different observing modes are not mixed so whenever you change modes always start a new data file. The data files produced always contain the standard La Palma descriptor packets and in some modes these descriptors contain all the information necessary to interpret the data. If this is inappropriate (e.g. in 'normal' photometry mode) then this extra information precedes the data in the data record itself. Standard Photometry Mode (e.g. PP11, PP22, MONITOR, STEPPER) Initially the size of the data file is defaulted to 1000 records although this can be overridden by a command line parameter. Note, however, that the file size can only be set before the file is created, an existing file cannot be extended. Each data record is of 256 bytes (the equivalent of 64 I*4 quantities) which are allocated as listed below. Bytes Type Quantity 1-20 5I4 (A20) Object name - character 21-24 I4 RA (HHMMSS.S) scaled by factor of 10 25-28 I1 Dec. (qDDMMSS) 29-32 I4 Equinox (x100) 33-56 6I4 Std mags/colours (x1000) 57-60 I4 Year 61-64 I4 (A3) Month - character 65-68 I4 Photometer pneumatic slide status (Juliet, Mode, Aperture, Romeo) 69-72 I4 UT time (days x 100000) of the middle of the integration 73-76 I4 Airmass (x1000) 77-80 I4 Integration time (secs) 81-84 I4 Total number of counts 85-88 I4 Q - statistic (x 1000) 89-92 I4 R - statistic (x 1000) 93-96 I4 G - statistic (x 1000) Bytes 65-96 are then repeated a further 5 times to give the same information for integrations with up to six filters. If a particular filter is not used, all quantities relating to it are set to zero. At present only the Q - statistic is implemented. This gives the ratio of the observed noise (standard deviation of the individual 1-second counts which comprise the total integration) to the theoretical Poisson noise. Note that the filter data are always stored in the data file in the order U B V R I - for the Johnson system and u,v,b,y,n,w - for the Stromgren system regardless of the position of the filters in the slides. For user-defined systems the storage order will correspond directly to the filters in the slides, i.e. the first filter data in the data record will correspond to that for the filter in slide position number 1 etc. Security and trouble shooting The data files created by PPAS in its normal, slow-continuous and polarimetry modes are direct access in the sense that a pointer to the next free data record is kept by the system and new data are written into that record regardless of the previous contents of the file. There is always a danger, therefore, that if this pointer gets corrupted useful data may be overwritten. In order to increase the security on this, the value of the pointer is kept in two separate locations and these must agree before any data can be written. Note also that the data record to be used next is output at the terminal at the start of any acquisition program - so an eye should be kept on this. The two data-record pointers are NFUN (next free unit) which is kept by the photometer control program and ANFUN (Adam NFUN) which is maintained by the ADAM environment. The procedure NEXTREC retrieves the value of NFUN from the photometer control program and the ADAM command PRINT ANFUN will give the value known to ADAM. Note also that WARMST will actually read the data file, look for an end-of-data record and set NFUN: so this is the safest way to look "inside" a data file. If you get any error messages about either of the record counters or even the data file itself the safest thing to do is to start a new data file by using NEWDATA. Before you do that however find out the values of NFUN and ANFUN and record them (on a Software Error Report preferably) together with the circumstances in which the error occurred. If any error occurs during the running of an acquisition progam then abort as soon as possible and change data files. WARNING Be warned that the system makes no check whether data already exist in a data record about to be written. It is therefore possible to overwrite data - this can be as useful as it is hazardous. Whenever ADAM is restarted or NEWDATA is run the system assumes that data recording will start at the FIRST record. Whenever either of these things happens and you wish to use an old data file which already has useful data in it you MUST run WARMST otherwise you will lose the data. END WARNING Slow Continuous Mode (SLCONT) This mode also produces 256-bytes records each one allocated as follows Bytes Type Quantity 1-20 5I4 (A20) Object name - character 21-24 I4 RA (HHMMSS.S) x 10 25-28 I4 Dec. (qDDMMSS) 29-32 I4 Equinox (x100) 33-36 I4 Airmass (x1000) 37-60 6I4 Standard cols/mags (x1000) 61-64 I4 Year 65-68 I4 (A3) Month - character 69-72 I4 Photometer pneumatic slide status 73-76 I4 Time resolution (msecs) 77-80 I4 UT date (DDHHMM) 81-84 I4 UT time (millisecs) on start of first data point 85-256 43I4 Data points - counts/time interval If data from both channels are being recorded the Romeo and Juliet data are written as consecutive data records. The twentieth character of the object name field is reserved for the channel identifier. Fast Continuous Mode (FCONT) In fast continuous mode only data values are written in the data file. The descriptors of the data file contain sufficient information to interpret the data. The data file record size is determined by the amount of data to be taken in an integration. If a total of > 4096 data points are to be acquired then the records size is set to 8192 bytes (4096 I*2 data points). If fewer data are requested the record size will be cut to the lowest multiple of 256 bytes which will still contain the data. The number of records in a data file depends on the number of channels used and the integration/time resolution combination. Scanning Slits Mode (SS) The most data that a full scanning-slits-wheel rotation can produce is 36 x 112 = 4032 (I*2) data points. For efficiency of writing to disc this is padded out to 4096. If the on-line binning facility is used, however, the record size will be reduced as above to the lowest multiple of 256 bytes which will still contain the data. The number of records in the file will be equal to the number of wheel rotations requested. Polarimetry Mode (POLAR) In this mode each data record contains a combination of system information, derived polarimetric quantities and the raw data. Each record is 480 bytes long and these are distributed as follows. Bytes Type Quantity 1-20 5I4 (A20) Object name 21-24 I4 RA (HHMMSS.S x 10) 25-28 I4 DEC (DDMMSS) 29-32 I4 Equinox (x100) 33-36 I4 Airmass (x1000) 37-40 I4 Year 41-44 I4 (A3) Month 45-48 I4 UT time (days x 100000) 49-52 I4 Coded filter, aperture positions and number of rotations of wave plate. Stored number = abcde where a = filter position, b = aperture position, cde = number of waveplate rotations 53-84 8I4 Stokes parameters and their errors. 85-88 I4 Linear polarization (% x 1000) 89-92 I4 Position angle of polarization (x 1000) 93-96 I4 Circular polarization (% x 1000) 97-480 96I4 Raw data = mean of the waveplate rotations Section D On-line photometric results For most observing programs it is desirable that some form of real-time result is available. At the very least it is useful as a check whether the correct object has been observed. PPAS provides a full transformation of the observed counts to the standard system (either Stromgren or UBVRI - user-defined systems are handled differently, see below). To do this it uses coefficients stored in files which have to be made known to the system. At startup default files are nominated. These are ROMSTR and JULSTR for the Stromgren system and ROMUBV and JULUBV for the Johnson UBVRI system. The photometric properties of the two channels are sufficiently different that they necessitate different sets of transformation coefficients. The coefficients in these default files were derived from standard star observations on a dust-free photometric night and therefore may not be applicable much of the time! They could certainly be improved with additional observations, particularly in regard to the secondary coefficients, so if you obtain substantial observations of standard stars please let the local staff know. The errors given with the on-line results derive from two calculable sources. Firstly the photon statistics and secondly the errors inherent in the transformation coefficients. Whether or not the errors in the coefficients are included in the errors displayed with the on-line results is determined by the commands COFFERR and NOCOFFERR - the latter is the startup default. To check the applicability of the coefficients for a particular night it is worthwhile setting COFFERR and then the on-line results should agree with the standard value to within the displayed errors. Reset to NOCOFFERR mode to check the internal accuracy being achieved on that object. When setting up an object file in PPAS (using SETOBJ) the user is prompted for any standard photometric values for the object - for objects in the "standards" file this information is available by definition. If this extra information is provided in SETOBJ then the object will be treated as a photometric standard and the on-line results will be available for recalculation of the transformation coefficients. Whenever an object is observed in PP11 or PP22 mode the raw (i.e. untransformed) on-line magnitudes/colours are stored in a separate formatted file. The name and status of this file are prompted for at startup but they may be changed using the OLPHOT? command. The advantage of this additional file is that the on-line estimates should have the sky count subtracted - this is automatically the case for PP22 and is so for PP11 if an object with a name beginning with the characters 'SKY' is observed before any object. Organizing correct sky subtraction in the raw data file is problematical especially in PP11 mode. After sufficient standard stars have been observed over a large enough airmass range, it is possible to analyse the coefficients using UBVXTRAN or STRXTRAN as appropriate. Each of these programs is explained in section E. If new coefficient files are created by this means then do not forget to inform the system of the new files by using the commands RCOFF and JCOFF. If a complete analysis is inappropriate it is possible to create coefficient files, by hand as it were, using SETUBVC and/or SETSTRC. These programs at least give the ability to, say, guess at the primary extinction coefficient in V - which is the coefficient most likely to change. Note, however, that the default coefficient values offered in SETUBVC and SETSTRC are the standard ones for the Romeo channel - they would all have to be entered afresh to create a new Juliet set. User-defined photometric systems are catered for in PPAS. All that is required is to set the filter names in the hardware file (use CHANGE), use NEWFILT to tell the system what the valid filter names are and then use MATRIX to set up the magnitude/colour derivation matrix. The program MATRIX also asks for zero points and primary extinction values for the magnitudes/colours defined. There are only two coefficients catered for with user-defined systems. The on-line results reported will simply be: raw - zero point - (primary ext)* airmass for each magnitude/colour. On-line analysis of the coefficients is not possible. Data stored in the on-line photometry file can be plotted using the OLPLOT command. See its own write up for details. The programs dealing with photometric transformations viz UBVXTRAN, STRXTRAN, SETUBVC, SETSTRC, LISTCOEF have been derived from the equivalent SPIDER programs written for the VAX by A C Collier. Their use will, therefore, be familiar to any VAX users of the SPIDER reduction package. Transformations used by PPAS for on-line reductions For the Johnson UBVRI system up to four coefficients are used for each magnitude/colour. These are the zero point, the primary extinction, the transformation factor and secondary extinction, - for the colours (V-R) and (V-I) the last of these is considered negligible. Otherwise using (U-B) as an example with lower case denoting raw values and upper case standard values we have (u-b) = Z(ub) + P(ub)*X(ab) + T(ub)*(U-B) + S(ub)*X(ub)*(B-V) For the Stromgren system there are similarly up to four coefficients per magnitude/colour. The secondary extinction term is here replaced by a colour term - but only for c1 and m1. For the Hb index the extinction terms are negligible. Thus with these restrictions and using m1 as an example we have m1(obs) = Z(m1) + P(m1)*X(m1) + T(m1)*m1 + C(m1)*(b-y) Section E Commands available within PPAS. AP(ERTURE) n - define aperture of size n arcsec to be used for the observations APS? - list the apertures known to be in the slide. AUTO - switches pneumatic control to automatic mode. If a pneumatic-set failure occurs, 3 tries at resetting are allowed before the run is aborted. This is the startup default mode. See "MANUAL" command. BS5050 -) use appropriate beam splitter when observing. BS9010 -)^]) BUTTON n - procedure to wait for button n of the handset to be pressed. CHANGE - Update the contents of the hardware definition file. CLOUD* - monitors (with plotting) the output from either channel. No data are stored. CLTIME n - sets the individual integration times used in CLOUD to n seconds. This overrides the integration time specified in the sequence requested. CLTOTAL n - sets the total time (n seconds) for which an object is monitored using CLOUD. COFFERR - include the coefficient errors in the calculation of on-line photometric errors. CONTRES - set up continuous mode time resolution (millisecs) CONTIME n - set continuous mode total integration time (secs) CPBIN n - average slow-continuous mode data by n bins before plotting. CPCNT - plot only raw counts in PSLCONT. CPMAG - plot instrumental magnitudes in PSLCONT. DARKCNT* - calculate the dark count in both channels. DT* - make observations to enable dead times to be calculated. DEFSEQ xxxx - define default sequence name. DESCR* - list the data file descriptors. DK a b - procedure to set the system dark count variables to a and b counts/sec for Romeo and Juliet respectively. FCONT* - acquisition in fast-continuous mode. FCSTATS* - statistics of a fast-continuous data file. FOSTER - user Foster prism for polarimetry observations. GOAP n - move the aperture slide to the position with an aperture of n arcsecs in it. Note that this command actually moves the aperture slide (if n is a valid number) unlike command AP which merely sets up an ADAM variable for later use. The two commands are not interchangeable and each must be used in the appropriate context. JCOFF xxxx - change the Juliet coefficient file name. JF n - set Juliet filter slide to position n. LD* - transfer the contents of a data file to a formatted text file which may be printed or displayed. LEXINIT - initialise the LEXIDATA; should be run before plotting for the first time. LEXPLOT - produce hardcopy of LEXIDATA plots on line printer LISTCOEF - produce a formatted file containing the photometric transformation coefficients from a named file. The output file must be printed in the usual way (see section I-11). LOBJ* - List the contents of the OBJ, RUN, SEQ or standard LSEQ object files. LRUN LSTD LSLC(ONT)* - produce summary listing of slow-continuous data file MAGOFF - switch off the reporting of on-line magnitudes and colours. MAGON - switch on the reporting of on-line mags/colours (default). MANUAL - switch to mode in which any errors in setting the pneumatics are reported but the acquisition programs will continue regardless. The programs still initially attempt to set the pneumatics according to the requirements of the requested sequence. MFILE xxxx - set the ADAM character variable to the name which will be the default MATRIX (qv) file. MATRIX* - create and store the colour/magnitude matrix for a user-supplied photometric system. MON(ITOR)* - semi-continuous monitoring of object MONT(IME) - the total time to be observed with MONITOR MOVAP a b - offset the telescope from current position by a, b arcsecs in RA, Dec respectively. Used to get aperture offsets right by trial and error. NEWDATA - set up a new default data file. This resets the data-record counter to 1. NEWFILT* - change the photometric system in use. NEXTREC - report at what record in the current data file the next data record will be written. Note that PRINT ANFUN should yield the same value. If it does not see section C. NOCOFFERR - do not include coefficient errors in the calculation of errors in on-line photometry. NORMAL - return to normal photometry mode after polarimetry mode (need hardware change as well). NUMCHAN n - set number of channels to be used in continuous mode. NUMSTEPS - set the number of steps to be used in STEPPER mode. OLPHOT? - ask for on-line photometry file name and its status - this procedure is run on startup. OLPOFF - switch off reporting of on-line polarization parameters. OLPLOT* - plot data from the on-line photometry file. OLPON - switch on reporting of on-line polarization parameters. PFC(ONT)* - plot fast-continuous data. PLOTAP x - determines which channel's data (x=R or J) will be plotted - used with STEPPER and CLOUD. PLOTDEV x - specifies the output device for plotting maybe either TEK or LEX. Default on startup is LEX. PLOTOFF - switch off plotting in relevant programs. PLOTON - switch on plotting for programs which have a choice. PLRANGE x - set the range of plots to x magnitudes. Plots will also be "expanded" by this amount if any datum falls outside the current plot range. POLAR - run the acquisition program for polarimetry mode. POLL(IST) - produce a summary listing of a polarimetry data file in a formatted file. POLP(LOT) - plot polarimetry data. PP11* - run the acquisition program which uses single channel mode. PP22* - run the acquisition mode using observations of the object in both channels. PPCOM* - add comments to data file descriptors. PPSTAT - report positions of pneumatic slides. PPTEST - puts the photometer pneumatics through their paces to check for mechanical problems. PSLC(ONT)* - plot slow-continuous data. PUTDESCR n - write descriptors to the data file header. If n is 0 the current data file is used; if n > 0, file Rn is used. Beware that this command first deletes all existing descriptors so don't run this after PPCOM. Must run this in order to get any sensible FITS descriptors. QDARK - request current dark count values (use DARKCNT to determine them afresh). RCOFF xxxx - change the Romeo coefficient file name to xxxx. REPOFF - switch off the on-line reporting of observed counts. REPON - switch on the reporting of observed counts. RF n - set Romeo filter slide to position n. RP* - produce a plot of the raw data from the normal-mode PPAS programs. Converts to magnitudes/colours as necessary. SEROBJ a b - search for and list objects from the OBJ file in range a < RA < b. SERSTD a b - ditto for photometric standards file. SETOBJ* - create, append to or edit the .OBJ file. SETRUN* - create or append to the .RUN file. SETSEQ* - create or append to the .SEQ file. SETSTRC )^]) - create a photometric coefficient file. SETUBVC ) SLC(ONT)* - slow-continuous acquisition. SLIDES a b c d - set slides to those positions specified by parameters a,b,c, and d. The order is Juliet filter, mode slide, aperture slide, Romeo filter. SS* n xxxx) - acquire and plot scanning slits data. See later SSCP* a b ) notes for further details and associated commands. SSP a b c d) STEP* - acquisition mode in which the aperture is stepped across the object and an integration performed at each step. On-line plotting is provided. STRSKY - use star-sky prism for observations. STRXTRAN - analyse standard star data to produce estimates of transformation coefficients in the Stromgren system. SWAP? - Determines the need for automatic aperture switching in 2-channel or stepper mode. Prompts for the offsets and is run at startup. Use MOVAP to check the appropriate offsets if they are not already known and then set them using SWAP? TESTDAS - writes to the DAS and reads data back to verify operation of DAS. TRUN* - truncate a standard data file to its minimum size and store in a new file. The original may then be deleted. UBVXTRAN - analyse standard star data to produce estimates of transformation coefficients in the UBVRI system. USEALL xxx ) set ROOT names for observation files. USEI(PL)? - to tell the system whether you want to do automatic object setting using the interprocessor link (IPL). This procedure is run as part of the startup. USEOBJ xxx ) USERUN xxx - ) set ROOT names for observation files. USESEQ xxx ) WARMST* - read the current data file and determine where within it the next free record is. Set the system pointer to this value so that data recording will start there. MUST be used if ADAM is restarted and the same data file as before is to be used or if NEWDATA is used and an old data file is to be appended to. Note: The commands marked with an asterisk are more fully explained below. Program CHANGE; command = CH(ANGE) Used to edit the contents of the hardware definition file. This is automatically run at startup but should also be run whenever a change is made to the photometer hardware. The acquisition programs use the hardware file to interpret requests for photometer settings e.g. the correspondence between filter names and pneumatic slide positions and its contents must be correct at run-time. The order (where relevant) of the quantities input refers to the pneumatic slide positions in sequence, e.g. entering A,B,C,D,E,F implies that filter A is in position one, filter B is in position two and so on. Note that for the built-in photometric systems (UBVRI and Stromgren) the filter names X and x (upper and lower case respectively) should be used to indicate missing or blank entries in the two systems. Program CLOUD; command = CLOUD Program to assess the transparency of the sky or constancy of any object. The photometer is set integrating for a given total time with individual integrations which can be specified. The counts are reported on the terminal and the instrumental magnitudes are plotted. Associated ADAM commands which must be set before using CLOUD for the first time (they may be changed individually thereafter) are: PLOTAP x - plot the data from channel R or J PLOTON - switch on plotting CLTOTAL n - set total monitor time to n (secs) CLTIME n - set individual integrations to n (secs) this overrides the value set in the sequence PLRANGE x - set the magnitude range for the plots. If any data point falls outside the original plot the range is automatically extended by this value and the data replotted. Note: 1) A sequence containing only one filter request should be used to set the photometer hardware. 2) NO DATA ARE STORED - this program does not access the data file. Program DARK; command = DARKCNT Calculates the dark count in each channel and sets up the appropriate system variables. If this, or the procedure DK, is not run before observing then warning messages about suspicious dark counts will appear for each integration performed. Prior to the main 30 seconds integration the program does a separate 2 seconds integration to check that the counts are reasonable (i.e. between 1 and 100). If not, a prompt whether to continue or not is given. The program may be terminated during an integration by pressing any of handset buttons 1-4. If you wish to bypass the determination of the dark count or the dark counts have been well determined previously, the dark counts can be set manually by running the ADAM procedure DK (q.v.). Note that DARKCNT is a procedure that packages the program DARK. If you want to change the integration time used (default = 30 secs) then run the program DARK in isolation but you should first set the dark counts to zero (use DK 0 0) and then run DARK INTIME = xxxx where xxxx = integration time required in seconds. In this mode you will have to grin and bear the messages about suspicious dark counts of zero, unless you want to be really clever and first set DK 1 1 and at the end remember to add one to the values found! Program DEADTIME; command = DT The deadtime for each channel's detector system can be calculated from observations of a variable intensity source (usually the twilight sky as it brightens or darkens). The command DT will set the photometer integrating for 5 secs (connection file default) alternately in each of the special dual 2mm/6mm apertures - these must be specially loaded in the aperture slide. The program will alternate on these apertures until either the count rate exceeds 4x106 counts/sec (defaulted) or any of the handset buttons is pressed. In either case the field view mirror will be inserted and the program stopped. DT DOES NOT SET OR RESET THE FILTER SLIDES SO THESE MUST BE POSITIONED USING THE 'RF' AND 'JF'COMMANDS BEFORE RUNNING DT. The first integration will be for only one second so that the count rate can be checked quickly. It is far safer to run DT on the dawn sky since it can be stopped when the count rates approach the maximum. If it is necessary to run DT on the evening sky then use the following as a guide-line. With a Johnson U filter in both channels*, exposing to the zenith sky 15 minutes after official (not by eye which can be misleading) sunset gives counts in the 6mm aperture close to the normal 4MHz limit. This can be reduced to 11 mins. after sunset if a Stromgren u filter is used. * (Do not forget this has to be done 'manually' before running DT) Program DESCR; command = DESCR Produces a listing on the terminal or line printer (or both) of specified descriptors in a data file. Procedure FCONT; command = FC(ONT) OBJECT This is the control procedure for fast, (1-10000 millisec time resolution) truly continuous data acquisition. It requires a rearrangement of the CAMAC wiring and should therefore be planned well in advance. The data are initially stored in the DAS CAMAC module. This has the advvantage that while one half of the memory is storing data the other half can be read out so there are no gaps between data points. It has the disadvantage of only being a 16-bit store so that total integration counts per time resolution should not exceed 32767. The purpose built AVG module is also used in this setup - it is this that directs the data to the correct DAS memory location. Unfortunately the AVG introduces a count-rate deadtime of its own, effectively limiting count rates to < 200 KHz. On the JKT this corresponds approximately to a broad band (UBV) magnitude of 8.0. The procedure FCONT has one parameter - the object name. If the name contains delimiters (spaces, commas) it should be enclosed in double quotes and owing to the vagaries of ADAM cannot be a pure number. FCONT also requires that a number of other parameters have been set up previously. These are: CONTRES n - the time resolution in millisecs CONTIME n - the total integration time in seconds NUMCHAN n - the number of channels of data to use n=1 for Romeo n=2 for Romeo + Juliet. It also assumes that the filter slides have been set and the position of the mode slide defined by e.g. STRSKY. For each running of FCONT a new data file is produced and the dimensions of the data file are dependent upon the data-taking parameters. The DAS can store up to 4096 data points per channel before being read out. At 500 millisec resolution this gives up to 34 mins of data. If the number of data points requested in the total integration time is less than 4096 then the data file record length will be adjusted to be the lowest multiple of 256 bytes that will contain the data, otherwise the record length with default to 4096 data points. In the case of a shorter record length there will be just one or two data records per file depending on the number of channels specified. The run number of the data file is automatically incremented by the FCONT procedure. If this is not what is required or you wish to reset the counter then use NEWDATA and request a number one less than the next data file you want created by FCONT. If the integration time is longer than 60 seconds, the procedure is streamed which allows the terminal to service other commands during the exposure. An exposure can be terminated at any time by pressing button 1 of the handset. The external frequency synthesiser must be set as appropriate for the time resolution requested. Details of the required setting are given when FCONT is run. Associated Commands NEWDATA - set/reset data file number CONTRES n - set time resolution (millisecs) CONTIME n - set total integration time (secs) NUMCHAN n - set number of channels to use RF n - set Romeo filter JF n - set Juliet filter STRSKY ) BS5050 ) - set mode slide BS9010 ) TESTDAS - test Data Acquisition Store hardware PFCONT - plot fast-continuous data FCSTATS - statistics of a fast-continuous data file Program FCSTATS; command = FCS(TATS) Since fast-continuous mode is likely to produce a lot of data, rather than producing a formatted listing of it or even a summary listing, this program will give some basic statistics of the data in a file produced by FCONT. This at least checks that the data exist and also gives some idea of their validity. Program LISTDATA; command = LD For the nervous observer this produces a text file (which may be edited, printed or displayed) summary of the data file. The input and output (data disc assumed) files are prompted for together with the start and end data records to be listed. The output file specified must be a valid Perkin Elmer file name and must NOT already exist. Do not give the disc specification, the system sets that up. The file extension is optional so that a valid file could be FRED.LIS or just FRED. See section I for how to get the output file printed. If you have started a print job which you subsequently regret, the job can be cancelled at the system terminal by typing .SPL CAN LP1: Note: you must NOT attempt to print the raw data file. This will only produce reams of garbage on the printer. Note that the correspondence between the data values and the filters used will 1) in the Johnson system always be in the order data (1) ... data (5) = U,B,V,R,I 2) in the Stromgren system always be data (1) .. data (6) = u v b y n w 3) in a user-defined system be data (1) ... data (6) = filter in position (1) ... filter in position (6). Program LSLCONT; command = LSLC(ONT) Produces a formatted summary file of a slow-continuous mode data file. Only the mean value of each record is shown so do not treat this file as a backup data listing. The input and output file names are prompted for but the output file must be printed "manually" - see section I-11. Portions of a data file may be output by selecting the appropriate first and last record - if you are unsure ask for 1,1000 and the program will stop when it reaches the end of the data. See the notes on LISTDATA on how to abort a print job. Program MATRIX; command = MAT The magnitudes and colour indices to be derived from the individual filter observations in any given system can be made known to the acquisition programs through the use of MATRIX. This information is mainly for use in the creation of magnitudes and colour indices for on-line display. For the UBVRI and Stromgren systems only this information is hard-coded into the programs so that for the first of these a request for on-line photometric results will yield (U-B) (B-V) V (V-R) (V-I) In general the information needed can be stored in a matrix (here limited to 6 x 6) of the form 6 input filters up to 6 . . . . . . output . . . . . . combinations . . . . . . . . . . . . . . . . . . . . . . . . Thus the UBVRI matrix has the form U B V R I X U-B = 1 -1 0 0 0 0 B-V = 0 1 -1 0 0 0 V = 0 0 1 0 0 0 V-R = 0 0 1 -1 0 0 V-I = 0 0 1 0 -1 0 For a user-supplied photometric system, specification of the appropriate matrix allows any combinations to be output. Indeed if only the magnitudes were required from UBVRI observations then the system could be redefined as an OWN system, a diagonal unit matrix having the desired effect. The actual format would be 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 The program MATRIX prompts for the matrix entries together with a 7 character name for the output combination and the zero point and primary extinction coefficients appropriate to that magnitude/colour. An example of its use for an arbitrary photometric system using filters called a,b,c,d,e and f is attached. The file in which the information is stored is assumed to have file type .MAT. If the ADAM command MFILE (q.v.) has been run the ADAM variable specified will be taken as the file name. See also NEWFILT. Note that when using an 'OWN' photometric system (even if using UBVRI filters) the columns of the matrix refer to the physical position of the filters in the slides. With the UBV filters loaded in positions 1-5 then to output on-line information of V,B and (B-V) only the matrix created would be U B V R I X V 0 0 1 0 0 0 B 0 1 0 0 0 0 B-V 0 1 -1 0 0 0 Example of setting up a user-defined photometric system with on-line magnitudes and colours. Adam:>MFILE EXAMPLE Adam:>MAT Give the name of the colour/mag formed >a Give six values for the matrix line :>1 (note any following values not supplied are set to zero) Enter the photometric zeropt and primary ext (0.,0.) > (null response so zeroes entered) Give the name of the colour/mag formed :>c-d Give six values for the matrix line :>0,0,1,-1 Enter the photometric zeropt and primary ext (0.,0.) :> Give the name of the colour/mag formed :>a-d Give six values for the matrix line :>1,0,0,-1 Enter the photometric zeropt and primary ext (0.,0.) :> Give the name of the colour/mag formed >e+f Give six values for the matrix line :>0,0,0,0,1,1 Enter the photometric zeropt and primary ext (0.,0.) :> Give the name of the colour/mag formed :>f-a Give six values for the matrix line :>-1,0,0,0,0,1 Enter the photometric zeropt and primary ext (0.,0.) :> Give the name of the colour/mag formed :>d Give six values for the matrix line :>0,0,0,1 Enter the photometric zeropt and primary ext (0.,0.) :> Adam:>PP22 Will start recording data at record # 1 Give the object or run name :>HR153 Move telescope to the NEW object HR153 when slew has finished, centre object & hit RETURN :> 01:37:20 Mean counts/sec. Romeo(a): 123 Juliet(a): 4 01:37:24 Mean counts/sec. Romeo(b): 108 Juliet(b): 18 01:37:28 Mean counts/sec. Romeo(c): 99 Juliet(c): 10 01:37:32 Mean counts/sec. Romeo(d): 98 Juliet(d): 6 01:37:36 Mean counts/sec. Romeo(e): 97 Juliet(e): 8 01:37:40 Mean counts/sec. Romeo(f): 96 Juliet(f): 9 Change to other aperture. Hit RETURN when ready :> 01:38:21 Mean counts/sec. Romeo(f): 13 Juliet(f): 94 01:38:25 Mean counts/sec. Romeo(e): 22 Juliet(e): 93 01:38:28 Mean counts/sec. Romeo(d): 14 Juliet(d): 92 01:38:32 Mean counts/sec. Romeo(c): 15 Juliet(c): 91 01:38:36 Mean counts/sec. Romeo(b): 12 Juliet(b): 91 01:38:39 Mean counts/sec. Romeo(a): 18 Juliet(a): 90 Complete 2 aperture data set for HR153 written to disc Object .. HR153 a c-d a-d e-f f-a d Romeo channel ... -3.138 -0.075 -0.273 -6.141 0.353 -2.865 .000 .000 .000 .000 .000 .000 Juliet channel ... -4.886 0.012 0.024 -9.854 -0.047 -4.909 .000 .000 .000 .000 .000 .000 Standard values ... -0.090 3.660 0.087 0.134 0.000 0.000 Give the object or run name :> Program MONITOR; command = MON(ITOR) The acquisition program to produce semi-continuous data. The observation is specified as normal through the OD files. The integration time specified in the sequence is taken as the integration time for individual observations, while the time specified by the command MONTIME gives the total time over which the monitoring observations take place. Note that the number of observations taken = MONTIME/SEQUENCE time. The elapsed time of the monitoring will therefore be greater than MONTIME because of "dead time" between integrations. The mode slide function is set beforehand using STRSKY, BS5050 etc. This mode produces 'normal' photometry type data files which can be listed (LD) and plotted (RAWPLOT). The main disadvantage of this mode is the 2-3 seconds dead time between integrations which means the data are not truly continuous and the integrations not contiguous. The mid-integration time is still recorded to an accuracy of about 1 second. The sequence specified for use within MONITOR should only request one filter. For instance setting MONTIME 500 and then using a sequence of SEQ = B-B-10 within MONITOR would result in 50 integrations each of 10 seconds being performed through the B filter in each channel. The mode slide could contain either the star-sky prism (in which case object and sky would be monitored) or a beam splitter (in which case different percentages of the object light would go to each channel) and then it might be desirable to have different filters in each channel - e.g. SEQ = B-V-10: Associated commands STRSKY BS5050 - set mode slide position BS9010 USEALL SETSEQ - set up OD files, sequence gives individual integration SETOBJ time DEFSEQ xx - define the default sequence APER n - set aperture to use MONTIME n - set up total integration time LD - list data into formatted file for later printing RP - plot data Program FILTSYS; command = NEWFILT While the acquisition programs are being run under ADAM there exists the concept of a "current photometric system". This can be changed by the command NEWFILT. This procedure is also included as part of the start up process so that the photometric system is prompted for at startup. At present there are 3 valid photometric systems. 1) Johnson UBVRI (system name = UBV) 2) Stromgren uvby Hbn Hbw (system name = STR) 3) OWN For the PPAS programs to work in cases 1) and 2) the filters specified in the hardware file must correspond to those requested in the sequence and they must be a subset of UBVRI for case 1) or uvbynw for case 2). If the photometric system required is neither 1) or 2) then the system must know what filters are involved. This it does via a filter file (file type .FIL assumed) which is created and filled by NEWFILT if and only if the response to the photometric system prompt is NEW. The user may then specify up to 12 (6 for each slide) filters which are to be recognised in this system. If the response to the photometric system prompt is OWN - then the program will assume that the filter names already exist in the .FIL file. An ADAM variable OWNFIL is loaded with the retrieved filter names so this may be inspected as a check. The ADAM variable PMSYSTEM denotes the system currently in use. Program OLPLOT; command = OLPLOT The program is a clone of RAWPLOT (see notes on that) with the exception that the data it plots are taken from the on-line photometry file. This has the advantage that the data are likely to be sky-subtracted which is important for an assessment of fainter objects. Program PFCONT; command = PFC(ONT) This program allows the data taken under fast-continuous mode to be plotted. If two channels of data were taken, the channel from which to plot the data is prompted for. The data to be plotted are defined simply in terms of a "first" datum and a "last" datum in the data file. If the range of requested data points exceeds 1000 then the data will be automatically binned as appropriate. Program POLAR; command = POLAR Polar runs the polarization mode of PPAS. Linear or circular polarization mode is determined by the waveplate identifier specified in the hardware file (H = linear; Q = circular). To run in this mode some hardware rearrangement is necessary. 1) Set the wave plate module rotating - see the hardware manual. 2) Insert the mode slide assembly containing the FOSTER prism. 3) Connect the appropriate CAMAC inputs - again details are in the hardware manual. The waveplate rotates once every 960 millisecs and ninety-six 10 millisec bins of data are taken each rotation. The time specified in the sequence is here interpreted as number of waveplate rotations to combine into one measure. The specification of object name, sequence and run name is standard. The derived estimates of polarization and position angle are given on-line for each channel's data. The format for the data file is different in this mode so do not combine this mode with others. See Section C for details. Note that if you wish to observe in a non-polarimetric mode after using POLAR then in addition to the hardware changes, issue the ADAM/PPAS command NORMAL. This will reset the CAMAC module setups. Associated commands CHANGE - make sure hardware file knows correct wave plate. USEALL ) set up OD files. Sequence time is interpreted as SETOBJ ) - number of wave plate rotations required (1 rotation = SETSEQ ) approx 0.5 secs). DEFSEQ x - set default sequence. FOSTER - set mode slide to Foster prism. APER n - set aperture to be used. OLPON ) - switch on/off on-line reporting of polarization OLPOFF ) parameters. POLLIST - produce summary listing of data and deduced parameters in formatted file. POLPLOT - plot polarimetry data and deduced parameters. NEWDATA - define new data file if required. DO NOT mix polarimetry and normal photometry in the same file. NORMAL - reset CAMAC hardware after using polarimetry mode if require to use normal photometry afterwards. Program POLLIST; command = POLL(IST) This program gives a summary listing of a polarimetry data file. It does not list the raw data but only the derived parameters. Running and printing the output file are the same as for commands LD and LSLCONT. Program POLPLOT; command = POLP(LOT) Allows plotting of any of the derived polarimetry parameters (intensity, Stokes parameters, linear polarization, position angle) as a function of time or phase in a given period. Operation is very similar to PSLCONT (q.v.). Program PP1A1S; command = PP11 For photometry of objects in crowded fields the convenience of the simultaneous measurement of the sky afforded by PP22 may have to be foregone because of the lack of choice over where the sky is measured. If this is so, the instrument can revert to a single channel instrument using PP11 as the control program. Only the Romeo channel is used, but in the event of disasters with the Romeo channel it is possible to feed the Juliet signal into the Romeo CAMAC connection and thereby fool the system. Only one data record will be created per set of observations. On-line magnitudes/colours are still possible since if an object name begins with the characters 'SKY' those data are written to ADAM variables and will be used by subsequent observations for on-line sky subtraction. This does not affect the data written to the data file, but is essential to get sensible on-line results. Note the form of response to input the object(s) to be observed. Possible inputs are for example 1) RUN1 - where RUN1 is defined in .RUN file 2) OBJ1 - where OBJ1 is defined in .OBJ file and will use the default sequence 3) OBJ2/SEQ1 - where OBJ2 and SEQ1 are defined in .OBJ and .SEQ files respectively. 4) Any combination of above up to max of 10 separate entries e.g. RUN1, OBJ1, OBJ2/SEQ1, OBJ1/SEQ2. See Section M for details of how to interrupt an integration. If an object name cannot be found in the current .OBJ file or the standards file it is treated as an 'on-line' object and its position will be prompted for (if the name was a mistake just hit RETURN in response to the RA prompt). When the full details of the new object are known they will automatically be entered in the .OBJ file for later use. Associated commands STRSKY - set mode slide. AP n - set aperture required. USEALL SETSEQ - set up OD files. SETOBJ DEFSEQ - define the default sequence. DARKCNT - determine PMT dark count in each channel. USEIPL? - switch on/off automatic slewing to object. OLPHOT? - to set up on-line photometry file. RP - plot raw data. OLPLOT - plot data from the on-line photometry file. PUTDESCR - write the data file descriptors. These contain details of the hardware and software set up. Use only once and before any comments are entered. Program PP2A2S; command = PP22 Acquisition program to obtain observations of an object by measurement in both channels. The objects requested are observed in the first aperture and then automatically repeated (the telescope move to the other aperture can be automatic or manual) in the second. On-line magnitudes/colours will be reported as requested. Each group of multi-filter observations will create four records in the data file (star and sky for both channels). The last character of an extended object-name field is loaded with either 'R' or 'J' to signify in which channel the observations were obtained. In most cases the program decides automatically in which channel the object is, but if the statistics become uncertain the user will be prompted for this information. In order to save on "start-up" time the program loops back to the object input stage. Hit RETURN to exit from the program. See the notes on PP11 for further details of object/sequence specification. See Section M for details of how to interrupt an integration. Associated commands STRSKY - set mode slide. AP n - set aperture required. USEALL SETSEQ - set up OD files. SETOBJ DEFSEQ - define the default sequence. DARKCNT - determine PMT dark count in each channel. USEI(PL)? - switch on/off automatic slewing to object. SWAP? - switch on/off automatic moving between apertures. MOVAP a b - use to empirically determine correct offsets between apertures. Can also use telescope controls in INCrement mode. OLPHOT? - to set up on-line photometry file. RP - plot raw data. OLPLOT - plot data from the on-line photometry file. PUTDESCR - write the data file descriptors. These contain details of the hardware and software set up. Use only once and before any comments are entered. Program PPCOM; command = PPCOM(MENT) Add 'comment' descriptors to the data file header. Each comment can be up to 40 characters long. Make sure you only run this AFTER running PUTDESCR because that clears all existing descriptors. Program PSLCONT; command = PSLC(ONT) Plot the data taken in slow-continuous mode. Points to note: 1) Only 1000 data points can be plotted. The data may be binned by using command CPBIN n before running PSLCONT. 2) Typing CPMAG or CPCNT before running PSLCONT will determine whether magnitudes or raw counts are displayed. 3) If you are uncertain of the name of the object to plot, answer with HELP and a list of valid names will appear. Note that these names will have the filter number(s) and channel identifier appended to the name you entered but to ease things a little all spaces will have been removed. 4) The user is prompted for the intensity and time windows of the data to be plotted. 5) It is possible to fold the data with a specified period. 6) Typing '?' in response to the 'next command' prompt will give the list of options. 7) When the plot program reads a data file record it assumes the first zero-value datum signifies the end of data in that record. Program RAWPLOT; command = RP Allows rudimentary plotting of data from the PP11, PP22, STEP and MONITOR acquisition programs. The data points for the object can be selected with reference to time and/or magnitude and may be pre-folded with a given period. The data from a comparison object may also be plotted on the same screen - in which case the scale of its plot remains that of the main object but with a zero-point offset. The list of acceptable commands can be obtained by entering a '?'. There are a number of features which should be noted, these include a) The integer part of the Julian day is always subtracted from the times plotted. b) Before plotting the data are transformed using the currently defined transformation coefficients. c) The colours or magnitudes which can be plotted are determined in the same manner as for on-line results in the acquisition programs. For Johnson UBVRI the default 'known' parameters are U-B, B-V, V, V-R, V-I and similarly for the Stromgren system. If these are not what are required then use MATRIX (q.v.) to set up a user-supplied system and ensure that the current ADAM photometric system is 'OWN'. d) All spaces in object names are ignored in RP. This allows easier access to the channel identifiers (R or J as the 20th character) WHICH MUST BE INCLUDED as part of the requested name. e) Answering HELP in response to the request for an object name will produce a list of valid object names. Program SETOBJ; command = SETOBJ Creates or appends to a .OBJ file which contains details of the objects to be observed. The program prompts for the object name (max 10 characters - just hit RETURN to exit) and then the RA and Declination (format: HHMMSS and (sign)DDMMSS all zeros are significant e.g. RA = 7 hrs 0 mins 9 secs must be entered as 070009). The equinox allows the object position to be processed at run-time for the air mass calculation. If the object is a photometric standard you may enter up to six magnitudes/colours (separated by commas) when prompted - see the section on dealing with on-line photometric results. If the object name entered already exists in the current .OBJ file, that entry will be overwritten with the new input. Note that if a run-time object name is not found in either the current .OBJ file or the photometric standards file its details may be entered at run-time and they will be saved in the .OBJ file. Program SETRUN; command = SETRUN Creates or appends to the current .RUN file. The prompts are for the name of the run (max 10 characters) and the list of objects/sequences or other runs which comprise this run. Run names may be embedded in the definition of other runs. Any object without a specific sequence qualifier will use the run-time default sequence. For example RUN1 could be specified as translating to STAR1, STAR2/SEQ1, STAR3/SEQ2. If a run name already exists, it will be overwritten. BEWARE ADAM has the "useful" capability of translating certain character expressions into data file specifications. Thus DELETE R1 would be translated into DELETE MTM:PHOCDP.001 if CDP was using the Photometer and the data files were on disk MTM. This "translation" takes place whether you want it or not and occurs in unexpected places. In particular if you define a run called R1 (or RUN1 or something similar) when you request it at run time it will appear as a data file name! The moral is avoid all run-names which approximate to ADAM reserved key words. See Section I-12 for more details - or even better read the ADAM manual! In short this means avoiding anything of the form Rn, Sn, Tn and An - in particular do not call your standard stars S1, S2 etc (STD1, STD2 is OK though). Program SETSEQ; command = SETSEQ Creates or appends to the current .SEQ file. A sequence name is requested (max 10 characters) and then the Romeo and Juliet filters (up to 3 characters each filter separated by commas - if only one is entered both are assumed to be the same) and the integration time for that filter combination. The program loops up to six times on the filter-integration time input - this is the maximum number of filter integrations allowed since duplication of filters within a sequence is illegal. Just hit RETURN to exit from the filter loop and again in response to the sequence name prompt to exit from the program. The .SEQ file produced is a text file which may be listed or printed (see program LSEQ) and may have entries of the form SEQ1 = U-U-10: F10-F09-30: 41-42-30: in which the current photometric system would have filter names U, F10, F09, 41 and 42 defined. Note that the acquisition programs make the link between filter name requested and the photometer setting through the entries in the hardware file which must therefore still be correct in their reflection of the hardware. If the sequence name already exists it will be overwritten with the new definition. Do not forget to avoid names like S1, S2 etc for sequences. Note that for slow continuous mode the interpretation of the 'integration' time specified in the .SEQ file is different than normal. Program SLCONT; command = SLC(ONT) The slow-continuous mode which allows the photometer to be set integrating with a time resolution in the range 250 msec to 1 sec. Data are gathered without interruption in "bursts" of N secs, where N is the time set in the sequence. The sequence requested should be for only one filter per channel. The data file created is large enough to take one hour's data at the chosen time resolution. If a NEW TIME RESOLUTION value is chosen for observations then a new data file MUST be started. This applies to the first value chosen! That is, always start a new data file when using SLCONT for the first time. The data records are the same length as for other observing modes which gives sufficient space for 43 data points per record. Each record also contains other "housekeeping" information - see Section C for further details of the data format. At present the telescope is unguided during any integration so the reason for dividing the observation into "bursts" is to allow rechecking of the object position in the aperture. A series of bursts may be terminated either by entering Q(uit) at the end of a burst or, if the termination is more urgent, by aborting with button 1 on the handset. Different objects may be observed and their data stored in the same file but do not mix observing modes in the one data file. Data from either Romeo or Romeo and Juliet may be recorded. The choice is set by the command NUMCHAN which takes a parameter 1 or 2. For example NUMCHAN 2 will ensure that data from both channels are recorded when continuous mode is used. The time resolution unit can be set by the command CONTRES N where N is the required resolution is milliseconds. Thus CONTRES 1000 will set up 1 sec integrations. If each integration time is more than 500 msecs the counts being recorded are output to the system terminal. The program SLCONT uses a temporary data file (R999 in ADAM terminology) to transfer data between the photometer control program and the acquisition program. This has two consequences for the user. Firstly do not use 999 as a data file number when using continuous mode and secondly the message that file MTM:PHOxxx.999 has been deleted is a normal part of the procedure and should not cause alarm. At present the method of data storage/transfer becomes very inefficient when CONTRES is less than H 500 millisecs. So consider using FCONT if you want observations with higher time resolution. After running SLCONT you should run PUTDESCR(IPTOR) - once per data file is sufficient - remember it will clear any comments you have added. It is not possible to plot or list the data in an SLCONT data file unless the descriptors are present. Associated commands STRSKY ) BS5050 ) - set mode slide position. BS9010 ) APER n - set aperture to be used (arc secs) USEALL ) SETSEQ ) - set up OD files SETOBJ ) DEFSEQ xxx - define the default sequence DARKCNT - determine the dark count in each channel CONTRES - set time resolution (millisecs) NUMCHAN - define number of channels to use LSLCONT - list a summary of the data into a formatted file PSLCONT - plot data from slow-continuous mode PUTDESCR - write data file descriptors. Must be used before data can be plotted. NEWDATA - set up new data file - must use new file if CONTRES is changed. Procedure SS; command = SS NROT OBJECT The command SS controls the scanning slits mode of the photometer. In this mode a rotating wheel is placed behind the aperture and slits in the wheel traverse the image in approximately 13 millisecs. Normally, also, in this mode the photometer is used together with the magnification box. This holds various microscope objectives which can be used to select a suitable scale in the focal plane. The high speed data are acquired using purpose-built CAMAC modules. Since using this mode requires considerable hardware changes both at the telescope and in the CAMAC setup, further advice should be sought before applications to use this mode are used. This acquisition mode is controlled at the ADAM procedure level. Calling SS will create a new data file (the data file number - ADAM variable RUNO- is incremented by one each time SS is run) and store the data from N rotations of the scanning slits wheel, where N is the first parameter to SS. The second parameter to SS gives the object name which will be saved in the data file descriptors. If this contains any delimiters (e.g. spaces, commas) the whole of it should be enclosed in quotes and owing to the vagaries of ADAM it cannot be a pure number since ADAM is expecting a character string. Beware also the R, S, T and A constructs (see Section I item 12). There are 36 slits in the wheel and the data from each slit traverse are collected in 112 bins. At the full data rate, therefore, each rotation of the wheel creates 4032 data points. Only the Romeo channel is used in SS mode. For computational efficiency each data record (corresponding to a single rotation of the wheel) is padded out to 4096 data points. For some applications it may not be necessary to have the full 13 msec time resolution in which case it can be acceptable to bin the data from several slits before storing. If data are binned on-line then the data file record length is adjusted accordingly to the smallest multiple of 256 bytes that will hold the data. On-line binning is controlled by the command OLBINSS N where N = number of slits' data to be combined. It can take the values 1,2,4,9,18 or 36. Binning by the full 36 slits gives a time resolution of H 480 millisecs, that is, the rotation period of the wheel. Do not confuse this binning with that of plotted data (in SSP and SSCP) which is controlled by the parameter SSBIN. All other functions of the photometer must be set individually (i.e. filters, aperture, mode slide) since no adjustments are made to the photometer within the SS command - apart that is from removing and inserting the field-view mirror at the beginning and end of a run. This is done for safety reasons. The command SSGL(ANCE) is a variant of SS provided for quick looks at the data. Data obtained with this command are stored in data file R0 (by analogy with the CCD software) and the data file number is not incremented. Beware though that the default file number for the plotting programs is the last authentic (i.e. > 0) run number so you will have to specify R0 explicitly for it to be plotted. Data files (other than R0) not written to tape are write-protected until dumped. If you want to delete them without dumping to tape use the PURGE command otherwise DELETE will work. Data taking runs that involve more than (or equal to) 100 rotations of the wheel are submitted as background processes in ADAM. This leaves the terminal free for other tasks but beware that the CPU is working pretty hard during data taking so do not try anything too heavy or the data taking may be adversely affected. Unfortunately this inlcudes plotting data - the one thing you would like to do! Runs may be aborted by pressing button 1 on the handset. Associated commands STRSKY - set position to which mode slide will be moved when field-view mirror is moved out. GOAP n - move aperture slide to position containing aperture of n arcsecs. Note that this command will actually move the aperture slide, unlike the AP command. RF n - move Romeo filter slide to position n. JF n - move Juliet filter slide to position n. FVMIN ) - move the field-view mirror in and out of beam. Run FVMOUT) automatically within SS and SSGL but can be useful at other times. OLBINSS N - sets on-line binning to N slits. The data file record length will be reduced accordingly. SSRESET - generally sets all SS, SSP, SSCP parameters back to default values. SSGL(ANCE) N - does a 'glance' run for N rotations. MTON ) - switches on and off tape dumping after each run. (If MTOFF) MTON use only MAG1: otherwise use FITSOUT later on either deck. NEWDATA - to reset data file number - note the next data file will be (the number specified +1). SSPLOT a b c d - plot the raw data. SSCPLOT a b - plot the centroid positions of raw data. Since some of the setup parameters used in scanning slits mode are not machine readable the following commands are provided. This information will then eventually find its way into the data file descriptors. SSMOBJ n - records the magnification factor of the microscope objective being used. SSDOVE n - records the position angle of the field = 1/2 pa of dove prism. FREQSYN n - records the setting used on the frequency synthesiser. This is nominally 84 KHz - but the last value determined which gave no drift relative to the wheel was 83.999685 KHz. These items will retain their values until explicitly changed and so need not be entered for every run. Procedure SSCPLOT; command = SSCP a b This is a procedure to plot the centroid position of the scanning slits data against slit number in the data file (effectively 'time'). Some elementary control over the centroiding process is provided as described under SSP. In particular the plot binning (SSBIN), THRESH and WINDOW parameters are always active - unlike in SSP where they are switchable on and off. The program plots all the data available within rotations 'a' to 'b' inclusive. If on-line binning was in operation, then the data points plotted (centroids) will have different time resolutions, but the time span of the data is written on the Lexidata screen. The best way to judge sensible values of SSBIN, THRESH and WINDOW is to plot some raw data using SSP first. Program SSPLOT; command = SSP a b c d It is essential to be able to inspect the scanning slits data as it is taken. The command SSP produces a simple plot on the Lexidata and other commands allow some elementary manipulation of the data prior to plotting. SSP takes four parameters, a b c d. The data plotted will be the integrated data from slits c-d (inclusive) of rotations a-b (inclusive) of the specified data run. The only manipulation of the data possible is that the data from each slit crossing (or combination of slits - see below) may be centroided before being added to data from other slits. This allows some compensation for image motion be it atmospheric or instrumental in origin. The effectiveness of the centroiding is governed by three other parameters which are set by the following commands before SSP is run. a) SSBIN n1; the data from n1 consecutive slits are summed before any centroiding. This increases the signal to noise but if n1 is too large some smearing will still be present. b) THRESH n2; Within the data only data values > n2 are used in the centroiding process. If SSBIN is used, do a raw plot of just n slits data so you can judge where to set n2. c) WINDOW n3 n4; for each slit's data only the data in bins n3 to n4 inclusive will be used to calculate the centroid. This gives the facility of masking off other objects in the field. With these parameters set use the commands ROLLON or ROLLOFF to switch on or off the centroiding procedure within SSP. LEXPLOT can be used to obtain a line-printer hardcopy of any display. Note that as will SS, the parameters to SSP retain their value until explicitly changed. Program STEPPER; command = STEP This program allows a series of individual integrations to be obtained while the aperture is stepped across an object. The stepping of the telescope can be done manually using the telescope INCrement button or automatically using the interprocessor link to control the telescope (use commands USEI(PL?) and SWAP? to set this up). If the filter sequence specified contains a request for more than one filter the program will step across the object in each filter consecutively (i.e. not run through the filters at each step). If the telescope control is in manual mode button 6 of the handset must be used to start each integration after a telescope move. During integration buttons 1-4 can be used to abort as usual. The data are plotted as they are taken. Associated commands APER N - define aperture to be used (arcsecs) USEALL ) SETOBJ ) - set up OD files SETSEQ ) DEFSEQ xxx - define default sequence. STRSKY ) BS5050 ) - define mode slide position required. BS9010 ) NEWDATA - set up new data file number. PLOTAP x - determines which aperture's data are plotted (x=R or J) PLRANGE x - set the range (x) in magnitudes for the ordinate axis of the plots. NUMSTEPS x - sets the number of steps (x) across the object. NUMCHAN x - sets the number of channels of data to record (x=1 for Romeo only; x=2 for both channels). USEI(PL?) - set step to automatic/manual mode. SWAP? - in this context the values entered into SWAP? give the steps in arcsecs between data points. RP - plot the data (after acquisition has finished). LD - list the data in a formatted file. PUTDESCR - write data file descriptors. Program STRXTRAN; command = STRX(TRAN) This program is directly equivalent to UBVXTRAN except that the Stromgren photometric system is assumed. The valid choice of magnitudes/colours is then b-y, V, m1, c1, Hb See the notes on UBVXTRAN for details of how to run the program. Program TRUNCATE; command = TRUN All the acquisition programs by default produce data files containing 1000 data records. This number is a connection-file default so see Section K if it needs to be changed. Since data files are not extendable at run-time they are created this size and will be unchanged even if only two data records are written to them. Truncated (i.e. only retaining records to which real data have been written) copies of data files can be created using the command TRUN. A new data file is created so that if this facility is used to save disc space, the original should be deleted. Note that the data files output by TRUNCATE CANNOT be used for further data acquisition. Program UBVXTRAN; command UBVX(TRAN) This is the program which derives the coefficients for the photometric transformations from observations of standard stars held in the nightly on-line photometry file. The data file used is that currently defined in the system so if you want to go over a previous night's data use OLPHOT? to set the system name accordingly - don't forget to switch back for data taking! When the program starts up you will be asked for 1) which channel's data are to be analysed - respond either R or J. 2) which colour/magnitude is to be analysed - remember that at all stages responding with a ? will give on-line help. 3) the range of airmass considered sufficient to enable a good determination of the primary extinction coefficients. If the observations of standards do not cover this range the primary extinction coefficient will be set to a standard value in all solutions. There are several options when you reach the COMMAND> stage. First of all try the ST(andards) command. This will list the number of standard star observations and the number of valid ones to be used in the next solution. The command TY(pe) will list the coefficients for the current colour/magnitude. Note that to begin with the Transformation and Secondary extinction coefficients will have an asterisk beside them. This denotes that they will be fixed parameters in the next solution. This is the default situation since observations on a single night are unlikely to be sufficient to obtain a better determination of these coefficients. If, however, you are determined to let them float in a solution then use the RE(set) command - this will "release" all parameters (use TY again to see that the asterisks have disappeared). If you subsequently want to fix any coefficient for the next solution, use command PR(eset) and answer the prompts (don't forget ? to get help). Since this mode loops internally type END to return to the COMMAND> option. If you want to change the colour/magnitude under consideration use the CO(lour) command. Note that only one colour is dealt with at a time so that the process of defining a complete set of coefficients involves using essentially the same procedure of data selection, coefficient setting/resetting and solving five times, once for each colour/magnitude. In order to inspect the data (of the colour/magnitude already chosen) use the ED(it) command. Accepting the defaults first time around will give a plot of raw mag v airmass. This quick look is useful to identify any bad measures. If you want to delete any data points from further consideration then give the appropriate response to the questions asked and use the Lexidata tracker ball/keys. To delete a point, move the cursor to it and press the delete switch (right hand most switch). A point can be readmitted to the fold by identifying it with the cursor and pressing the switch labelled 'restore'. To exit from the cursor routine press the left most switch labelled EXIT. Once you are satisfied with the quality of the data and with the set/float status of the coefficients, use the SO(lve) command. This will perform a least squares solution for the free parameters and list the resulting coefficients. It is useful to do a TY immediately before an SO so that you can see the before and after results on the screen together. After using SO(lve) the data can again be inspected using ED(it). This time the defaults will give you a plot of residuals against airmass - they should of course cluster around zero! If you are satisfied with the results move onto the next colour and repeat the process. If at any time you want to leave the program without any further action type QU(it) in response to the COMMAND> prompt. You can write the current version of the coefficients to a disc file at any stage using WR(ite) - it is OK to overwrite previously existing coefficient files, but not the standard default ones. If you wish to exit from the program in an orderly manner, but first to write out the coefficients use the command EX(it). Note that the program LISTCOEF can be used to produce a hard copy of the contents of any coefficient file produced. Program WARMST; command = WARMST Reads through the current data file to find the next record which is free and available to receive data. This allows previously-used data files to be re-used after an exit from ADAM or after a change of data files. The next-free-data-record counter is set automatically. See also commands NEXTREC and NEWDATA. Section F Storing data on tape The data files created by the PPAS are standard I4 bulk data files which may be treated as "image" data and written to tape in FITS format. Four 'FITS' programs are available. They may be run under ADAM by typing in the name of the program e.g.: FITSINIT - must be used ONLY when a virgin D-tape is being written to. FITSOUT - will dump disc files to tape. FITSOUT will carry on dumping from the present position of the tape without rewinding. Unless a FITSINIT is performed first, files will be appended to any existing ones. FITSDIR - gives a listing of the headers of all files on tape if that mode is chosen. FITSIN - reads a file from tape and dumps it in a disc file. Don't forget to use the Rnnn construct to ease the specification of the data files (see Section I item 12 or the ADAM manual) thus to dump file numbers 1, 2, 3, 4, 9, 10, 15, 16, 17, 18, 20 to tape, the response within FITSOUT to "which files to write out" could be, in its briefest form: R1-4, R9-10, R15-18, R20. Section G Photometer Apertures The PPAS will only recognize the following apertures as valid on the JKT. Hardware file Value requested with AP command (mms) (arcsec) 0.5 7 0.7 10 1.0 14 1.5 21 2.0 28 2.4 33 3.0 41 3.5 48 4.5 62 5.2 72 6 83 8 110 10 138 Sizes in arcsec are given to the nearest arcsec assuming a scale of 13.8 arc seconds/mm. for the JKT. Note that in the hardware file (program CHANGE) the aperture size are specified in millimetres since this is how they are identified on the aperture plates but when requesting an aperture to be used for an observation the value is specified in arcsecs - since those are the units the observer will be thinking in by that stage. Section H The PPAS hardware definition file Since the various components of the photometer are not distinguishable remotely by the instrumentation computer, PPAS has to be kept informed of the hardware setup by less direct means. This is achieved through a disk file on the instrumentation computer whose contents should at all times reflect the current hardware setup. Access to the file is through the command CHANGE, which is part of the startup sequence, but which should be run explicitly whenever a hardware change is made. If this is not done there is a good chance that you will observe with the wrong hardware configuration without, in some cases, being aware of it - until it's too late. The hardware information will be stored as data file descriptors when the command PUTDESCR is run. Ideally a new data file should be started each time the hardware is changed, otherwise the descriptors will not accurately reflect the state of the hardware at the time the data were taken. A hardcopy listing of the file can be obtained by printing file MTM:PHOT.HAR/G (see section I item 11). Section I Running ADAM and the PPAS 1) SIGNON under any account from 1 to 8 (password same) e.g. SI CDP, 2, 2. The underlined initials should be your own. These will be used by ADAM to name data files (see ADAM manual). 2) Type in ADAM to startup the system and then select F/15 and Peoples Photometer as your working configuration. 3) Answer the prompt for a file number extension. This will set up the default file for data as data:PHOabc.nnn where data = name of data disk (usually MTM) abc = SIGNON initials and nnn = file number extension. For the normal modes which do not create much data, it is a convenient convention to use the day of the month as the file number. 4) Change any part of the hardware setup as necessary. 5) Enter the photometric system you wish to use - default is the one used last. 6) Enter the name (up to eight characters) of the file to be used for storage of on-line results. (Its full name will be name.FOT and it will be on the data disk (usually MTM but in any case defined by ADM_DVOL); it may be printed if desired.) If you give a null response here, any program requiring to use this file will reprompt for a valid name. You may use the command OLPHOT? to change the filename at any time. 7) Respond whether you want this file to be started afresh or appended to. If you are starting up after a power fail, say, you will want to append to the old file otherwise you will probably want to start afresh. 8) Reply to the questions about whether you want to use the IPL for telescope control. (If you do, but don't know what aperture offsets are required just hit RETURN in response to those subsequent questions. Once the values are known they can be set by running SWAP? later). 9) If another terminal is available on the PE3220 it may be used to access, list and edit files but no other work should be done on the PE3220 while an integration is being performed. 10) Within the application/observing programs, help is usually available about the necessary responses to prompts by replying with a question mark '?'. If it isn't, complain! 11) Note that one-line commands may be given in an out-of-ADAM environment by pressing the terminal BREAK key once when in ADAM, entering the command and pressing RETURN. As soon as the RETURN key is pressed the terminal will revert back to ADAM. This facility is especially useful for printing files - output from LD say. Never attempt to print the 'raw' data file. You may only print the output from programs LD, LSLCONT, POLLIST or the 'OD' files themselves, the on-line photometry file or the hardware file. Example: ADAM> (hit BREAK) * PRINT MTM:CDP001.LIS > back to ADAM. 12) As you may have gathered from reading the ADAM manual, ADAM has certain 'reserved' keywords. The most important of these are the Rx, Sx and Tx and Ax constructs where 1 < x < 9999 and which in any context within ADAM will be expanded into a full data file specification e.g. R1 could be expanded to MTM:PHOCDP.001. This applies even to the answers given to prompts within PPAS. hence don't try to set up any runs in the .RUN file with names like S1, A6, T3, R1 or R99 - you will be amazed at the result! Section J A typical observing setup Once you are over the startup procedure (Section I) and have received the ADAM> prompt, there are a number of things to set up before observing can begin. The following checklist can be used as a rough guide to at least get you on the road for the normal photometry modes: 1) When it is dark in the dome (remember the photometer is not strictly light-tight - but in any case don't forget the eyepiece cap) run DARKCNT to determine the dark count in each channel. This can also be run as a first diagnostic to see if counts are being recorded. 2) Define the name of the observation definition files either using USEALL xxxx or set them individually e.g. USEOBJ. 3) Define which aperture you want with AP x where x is in arcsecs. If you don't know what the system thinks is loaded use APS? Remember the hardware file apertures are in millimetres but here you request arcsec. 4) Define the mode of operation (essentially the position of the mode pneumatic slide) by requesting one of STRSKY, BS5050, BS9010 or FOSTER. 5) Define the default sequence name by DEFSEQ xxxx. 6) If you do not want the standard transformation coefficient set, use RCOFF xxxx and/or JCOFF xxxx to change the default file names. 7) If you are using a non-standard photometric system then, if you haven't already, run NEWFILT and MATRIX and then define the matrix file using MFILE xxxx where xxxx is the file name specified when you run MATRIX. 8) If you intend to use any plotting programs, run LEXINIT to reset the Lexidata. If this fails try it again, if that fails try switching the controller (in the 3220 racks below MAG2 - take the front cover off) off and on and then try LEXINIT again. 9) If the data file you specified on startup already contains data (you will have been warned) and you wish to append to it rather than overwrite it, run WARMST. 10) To test the pneumatic slides are working OK use the command SLIDES a b c d with a few different values. Remember 1 < a < 6 for the Juliet filter slide 1 < b < 3 for the mode slide 1 < c < 3 for the aperture slide 1 < d < 6 for the Romeo filter slide are the only valid values. An error will be reported if the slides fail to reach their requested positions. Note that the procedure PPTEST will perform a more thorough test of the pneumatics. It takes a couple of minutes to complete but is worth running particularly at the start of a run. Make sure the pneumatic control box at the photometer is set to CAMAC before running PPTEST. Section K Connection file defaults Each program run under the ADAM environment must have an associated "connection file" (filename.CON) through which it communicates to the environment. If a program requires parameter input but this information is unlikely to change from one running of the program to the next, this information may be set as a default in the connection file. The effect of this is that the data are available to the program without the user being prompted for them. If it is necessary to change the values of defaulted values, they may be reset on the command line that starts up the program in question. Thus, when a new data filename has been defined using NEWDATA (or as part of the normal startup), the size of the file may be changed from the default size of 1000 records by specifying the parameter D1M2 on the acquisition program command line. Note that this particular example can only be used for a new (as yet unused) data file - it will have no effect or extant files. Thus PP11 D1M2=5000 will create a data file five times the normal size. The defaulted parameters in the various PPAS programs can be found in the listings of the connection files given in Section N. Section L Controlling the telescope from within PPAS Now that the interprocessor link (IPL) between the PE 8/16E telescope control computer and the PE 3220 instrument computer is working, it is possible to control the telescope through the PPAS software. The most obvious places this can be useful are in slewing to a new object, offsetting between the double apertures when in two channel mode (PP22) and stepping the telescope across an object (STEPPER). Automatic slewing has the advantage that the object's position and equinox need only be entered once, in the .OBJ file, rather than at the telescope control user interface as well. When initiating a slew, the PE 3220 sends the required position to the source name .LINK (the third predefined object in the user interface object list) so that when this method is being used, the information display on the control desk will show .LINK as the name of the NEXT source. At the moment it takes approximately 6 seconds from the sending of the first object position information to the commencement of slewing. The start and finish of the process can be monitored by checking the position error display on the control desk although the programs themselves do check for successful completion of a move. When switching between the double apertures in 2-channel mode use the procedure SWAP? to set the values. With the apertures N/S and the telescope East of the pier, the offsets from the Romeo channel to Juliet are approximately (RA = 0, Dec = -175 arcsecs). The exact value changes with the aperture plate used and will obviously change if the instrument rotator angle is changed at the telescope. The sign of any Declination offset will also change if the telescope is used West of the pier (e.g. if the telescope is West the values in the example above would be (0, +175) arcsecs. Section M Using the handset to interrupt data acquisition The Peoples Photometer is provided with a six-button handset which is linked directly to CAMAC and whose status is read every second during data taking. The buttons of the handset can be used to interrupt the data acquisition process at different levels. Their action is as follows: Button 1 Exit from the acquisition program completely and return to the ADAM prompt. Button 2 Stop data acquisition and return to the point where the acquisition program requests the next object or run name. This, plus a null answer to the prompt, has the same effect as Button 1 but gives more time for a change of mind. Button 3 If within a multi-object RUN, then stop data taking and restart at the beginning of the Current object. Continue with the rest of the RUN if appropriate. Button 4 If within a multi-object RUN, then stop the data acquisition on the current object and start at the next object in the RUN. If only a single-object observation was in progress then this will have the same effect as Button 2. It should be emphasised that the handset status is only read WHILE AN INTEGRATION IS IN PROGRESS. The buttons will have no effect at other times. If you wish to take advantage of one of the effects of the buttons you must first start an integration - even if you mean to cancel it immediately! It is usually necessary to press the buttons several times before they are 'seen', just press the button until the "Abort noted" message appears. Note also the procedure BUTTON n (n=1,6) which when called, will just wait until button n of the handset is pressed and then exit. Section O Peoples Photometer Photomultiplier Tube Log Tube ________________________ Temperature Setting __________________ Channel _____________________ Date Dark count/second Deadtime (nanosecs) _________________________________________________________________________ | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| Peoples Photometer Photomultiplier Tube Log Tube ________________________ Temperature Setting __________________ Channel _____________________ Date Dark count/second Deadtime (nanosecs) _________________________________________________________________________ | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________| | | | | |_________|__________________________|__________________________________|