In a line of input to the user interface, all characters following an asterisk are ignored by the command processor. In prepared or SAVEd files it is often useful to indicate the purpose or significance of the commands that follow, to flag and date amendments or to indicate the source of the data values appearing as arguments of commands. Comments may be in blocks of lines, each with an asterisk in column 1, or as in-line comments following a command and its argument.
At the console the text is ignored and the user is prompted for further input; in a file the command processor ignores the text and moves on to interpret the next line. There are no qualifiers.
AC(QUIRE)
defines the autoguider acquisition mode and is used to tell the system whether to move the guide-probes or the telescope when acquiring a guide star. Veteran observers should beware the reversal of definitions compared with the historical case.
AC(QUIRE)/PR(OBE) moves the guide probes until the guide-star is centred while the telescope remains fixed (tracking). It is used when the object of interest is already positioned in the TV or on the CCD chip and should stay where it has been put. The position of the guide star will probably not be known very accurately and moving the telescope rather than the probe would cause the target to move.
AC(QUIRE)/TE(LESCOPE) moves the telescope to acquire the star while the guide-probe remains fixed in the focal plane of the telescope. It is used when the guide star position is known precisely a priori ; either because it has been observed before and the probe position is known or because the offset between it and the target has been measured in advance.
ADVISE
gives details of a source, telescope or UI parameters, or lists the source-names in the resident catalogue.
AD(VISE)/S(OURCE) source-name
gives details of source-name and times to rise and set from
a given time. The output is in LST and an example is given in
Figure 
. The desired time is input using SET/LST or SET/UT.
If no time has been set, the current time is used.
AD(VISE)/E(DIT)
gives details of the edit source and times to rise and set from a given time. This time is input using SET/LST or SET/UT. If no time has been set, the current time is used.
AD(VISE)/N(EXT)
gives details of the next source and times to rise and set from a given time. This time is input using SET/LST or SET/UT. If no time has been set, the current time is used.
AD(VISE)/CU(RRENT)
gives details of the current source and times to rise and set from a given time. This time is input using SET/LST or SET/UT. If no time has been set, the current time is used.
AD(VISE)/T(EL)
gives all telescope parameters such as SET/GUIDE/INCREMENT rates, offsets,
focus position and the like. Sample output Figure .
AD(VISE)/CAT
gives a list of only the source-names and sequence-numbers in the resident catalogue. This is a useful command to inspect object names in a large catalogue. Its output, however, is formatted to fill the line accross the VDU screen.
AD(VISE)/UI
gives coordinates of the edit, current and next sources, acquisition and telescope modes and the time set by SET.
AP(ERTURE)
AP(ERTURE)/A x y (arcsecs) sets aperture A
AP(ERTURE)/B x y (arcsecs) sets aperture B
sets up aperture offsets defined in an X-Y coordinate system fixed in the instrument rotator. These can be used, for example, to locate an object within a particular aperture or detector pixel. An aperture offset is executed by pushing one of the beamswitch buttons on the control desk.
If it is required to beam-switch (for example on a two channel photometer), then the apertures can be set up using the qualifiers /A and /B with X-Y offsets in arcsecs as input parameters. The control panel BEAMSWITCH buttons A, NOM and B (near the centre of the `System Control' Panel) are then used to select between either aperture or the nominal position. If the required aperture offsets are not known a priori then the /A and /B qualifiers for SNAFU may be used to set them up interactively.
APERTURE is applied as a pointing correction, so it is not reflected in the displayed telescope position: conceptually, applying an aperture offset causes the SAME object to be observed using a DIFFERENT area of the instrument whereas an RA/Dec offset causes a DIFFERENT object to be observed on the SAME part of the detector and therefore causes the displayed position to change. The RA & DEC displacements corresponding to a particular aperture offset will vary with the turntable rotator position angle (unlike that for an RA/Dec offset, of course), but the displacement on anything attached to the rotator (TV, CCD, IPCS) will remain constant. All of the aperture offsets are calculated relative to a nominal aperture position which is specified in the system startup (.STD) file and corresponds to an easily visible reference position (the Grinnell crosswires or the centre pixel of an imaging CCD). This is because the reference position does not usually coincide with the rotator axis (which defines the origin of coordinates). The displacement between the reference position and the rotator axis (the base aperture offset) must be calibrated from time to time. For the INT at prime focus, the reference point is in the centre of the CCD chip (10 arcmin off-axis), but for the Cassegrain systems on both telescopes, SNAFU is usually done on the Grinnell cross wires so the reference aperture offset is set up to be the (small) difference between the turntable centre of rotation and the Grinnell cross-wires with the TV in the centre/acquisition position.
AUTOFFSET
is a method of doing precise blind offsets which gets round errors in the declination encoder. The telescope and guide probe are offset by equal and opposite amounts whilst autoguiding, and the guide star is kept at the centre of the autoguider field. This exploits the fact that the probe encoding is more accurate than that of the telescope. It is recommended for blind ofsetting and for 2D spectroscopy when the slit is moved by small increments to cover the field.
AU(TOFFSET)/B(OTH) RA & DecAU(TOFFSET)/R(A) RA\
AU(TOFFSET)/D(EC) Dec
sets up the telescope offsets in arcsecs in RA, Dec or both according to the qualifier. These are defined in a tangent plane projection centred on the current position of the telescope. The telescope begins to move as soon as Return key is pressed. As the telescope moves to the OFFSET the autoguider automatically follows the reverse vector so that it does not lose the guide star. Be careful: there is always the danger that the autoguider probe may move to a position where it cannot see the guide star. Further, if you press the OFFSET NOM button after an AUTOFFSET then the telescope returns to its previous position but not the autoguider probe. BEAMSWITCH
is synonymous with APERTURE
D(EC)
D(EC) dd mm ss.s
enters the declination for the current edit source. The format is: degrees minutes seconds. The seconds and minutes may be omitted but then the command must be terminated explicitly either by a carriage return or by a semicolon `;'. There are no qualifiers.
DELETE
deletes sources from the catalogue according to the qualifier.
DEL(ETE)/F(ROM) source-name source-name
deletes the sources in the resident catalogue between and including the given source-names. If only one source name is given, only that source will be deleted.
DEL(ETE)/A(LL)
deletes all sources in the resident catalogue except the first three, since .DEFAULT, .GUIDE and .LINK are protected sources (for e.g. input from the autoguider or via the interprocessor link).
DEL(ETE)/S(EQ) sequence-number sequence-number
deletes sources in the resident catalogue between and including the given sequence numbers. If only one sequence number is given, only that source will be deleted.
DIFF\?RATES
DIF(F\?RATES)/B(OTH) RA-rate (secnds/sec) Dec-rate
(/sec)
DIF(F\?RATES)/R(A) rate(sec/sec)
DIF(F\?RATES)D(EC) rate(/sec)
sets up differential tracking rates in RA,Dec or both (according to the qualifier). This will be actioned by pressing the `differential track' button DIFFRATE in the right-hand lower corner of the System Control Panel. Note that this mode is switched off upon source change.
EDIT
E(DIT) Source-name
selects the given source as the edit source. There are no qualifiers. If you define a new source name with the SO command, it will become the current 'EDIT source'.
EQUINOX
EQ(UINOX) Byear
EQ(UINOX) Jyear
EQ(UINOX) A(pparent)
sets up the mean coordinate system (B for Besselian or J for Julian) and the equinox (year) for the edit source. The equinox for apparent coordinates is assumed to correspond to the current date. FK4(B1950.0) and FK5(J2000.0) will eventually be supported, but at the moment only FK4 is implemented. Note that B, J or A must be specified.
FOCUS
F(OCUS) position (mm)
Sets the required focus position. The telescope focus will be driven to this value when the FOCUS NOM button on the control desk (right-hand side of System Control Panel) is pressed. Pressing the FOCUS STOP button halts a focus drive. Once the focus drive has been set it will track to follow any change in tube temperature. There are no qualifiers. The position value is mm of motion of either the secondary mirror (Gassegrain mode) or the instrument at Prime. Increasing values mean that the secondary or primary instrument is moving further from the main mirror.
GOTO
GO(TO)
slews the telescope to the NEXT or given source and initiates tracking.
GO(TO)/N(EXT)
is equivalent to pushing the T/S DOME SRCE button on the control
panel. It will move the telescope to the NEXT source and initiates
tracking. If the source is within the
software limits, then the green go lamp will light up and the telescope
will commence slewing. If the object is beyond any (soft) limit, then the
go lamp will only flash briefly and the red stop lamp will be lit.
Appropriate messages will also be output to the Information Display (see
section ).
If you changed your mind while the telescope is moving push the STOP button to halt the slew.
GO(TO)/SO(URCE) source-name
slews the telescope to the named source and initiates tracking. Beware, this option has not yet been tested!
GUIDE\?OBJECT
GU(IDE\?OBJECT) guide-name
defines a guide object for the edit source by linkage to an existing entry in the catalogue containing the coordinates of the object which you want to be the guide star. After the telescope is pointed to a new source and the GUIDE PROBE button GUIDESTAR is pressed on the Acquisition and Guidance panel (A&G, the right-hand panel in bay 3, NOT to be confused with the Autoguider Panel), the probes will drive to the position of the guide object, but only if it is at a legal position, i.e. within its physical limits. This procedure can be used when the coordinates of a guide star are known in advance. There are no qualifiers.
HANDSET
HA(NDSET)/A(LL) set-rate guide-rate increment HA(NDSET)/S(ET) set-rate [0 - 75] /secHA(NDSET)/G(UIDE) guide-rate [0 - 75] /sec
HA(NDSET)/I(NCREMENT) increment [0 - 6000]
This command inputs the set and guide rates and the increment step to be actioned by the handset and/or the `arrow' buttons on the System Control panel, and the XY AXES buttons SET, GUIDE and INC, which are found in the lower-left corner of the System Control panel. When in SET or GUIDE mode, the motion is continuous; when in INCREMENT mode, the motion is stepped everytime the button is pressed. If you change a HANDSET parameter the control software will not adopt the new value until the appropriate button has been pressed.
H(ELP)
H(ELP) Command
provides on-line help information about a specific command. There are no qualifiers.
INPUT
I(NPUT)
inputs a catalogue from a specified disc file.
I(NPUT)/N(ORMAL) file-name
If no extension of the file-name is given then .CAT is assumed. A maximum of 500 entries in the catalogue is allowed.
I(NPUT)/PROMPT device name:
This is used on startup of the user-interface to select input from this terminal interactively, and is rarely needed.
LIST
L(IST)
will list the source names and coordinates from the resident catalogue.
L(IST)/A(LL)
will list the whole resident catalogue to the screen, pausing after each page to ask whether more output is wanted.
L(IST)/F(ROM) source1 source2
will list from source1 to source2 on the screen.
L(IST)/PR(INTER)
will list the whole resident catalogue to the line printer.
NEXT
N(EXT)/NA(ME) source-name
N(EXT)/SEQ(UENCE) sequence-number
defines the next source to be observed, selected by name or sequence number according to the qualifier used. .DEFAULT is number 1, .GUIDE is number 2 and so on through the catalogue.
OFFSET
O(FFSET)/B(OTH) RA-Offset Dec-Offset O(FFSET)/R(A) RA-Offset ()O(FFSET)/D(EC) Dec-Offset ()
Sets up the telescope offsets in arcsec in RA, Dec or both (according to the qualifier). These are defined in a tangent-plane projection centred on the current position of the telescope. They are actioned by the control panel OFFSET buttons. Pressing OFFSET will action the offset; pushing the NOM button will return the telescope to the original position. The current offset values are displayed on the information display. Beware: If you use the FOCUS or MULTEXP commands from the ADAM terminal then you will find that any values you have previously entered for OFFSET have been overwritten.
PROPER\?MOTION
P(ROPER\?MOTION)/B(OTH) RA Dec P(ROPER\?MOTION)/R(A) RA (secs/year)P(ROPER\?MOTION)/D(EC) Dec (/year)
sets the proper motion of the edit source in RA,Dec or both. The corresponding epoch is assumed to be the same as the equinox. Note the different units!
RA
R(A) hh mm ss.s
sets up the Right Ascension for the edit source. This format is hours minutes seconds. As with D(EC) the last two are optional but the command must be terminated with a semi-colon if they are omitted. There are no qualifiers.
ROTATOR
RO(TATOR) position (deg)
synonym for TURNTABLE (q.v)
SAVE
SA(VE) Filename
saves the catalogue in memory to a user-specified disk file, which will have a .CAT extension, whatever extension was defined at the User Interface; if you were to specify another extension, a warning would appear: `File type is forced to .CAT'. There are no qualifiers.
SET
Sets up various UI parameters for the ADVISE () command according to the qualifier:
SET/LST hh mm ss
sets up the Local Sidereal Time for use by the ADVISE command.
SET/UT hh mm ss
sets up the UT for use by the ADVISE command
SET/NOW
ADVISE will use the current time (this is the default on startup)
SNAFU
sets up the telescope collimation and index errors or the aperture offsets.
SNAFU/NOMINAL
sets the collimation and index errors.
The sequence of events for a ONE-STAR SNAFU is as follows:
The qualifiers /A and /B enable the different aperture positions to be recorded by the system for use by the BEAMSWITCH buttons A and B. The procedure is:
SO(URCE)
defines a new entry in the source catalogue. Note that the first three entries, .DEFAULT, .GUIDE and .LINK, cannot be deleted nor redefined, because they have a dedicated function in data transfer via the CAMAC interfaces. For instance, .LINK is used to transfer source data from the PE 3210 instrument computer over the interprocessor link, and enables the sending of a pointing command to the telescope control software from the ADAM environment.
A newly defined entry automatically becomes the current 'edit' source, so its parameters (RA, Dec etc.) can be entered immediately. Note that, until a new SOURCE command is issued, all commands which specify source parameters (e.g. RA, Dec, P, etc.) will update the values associated with the 'source-name' last entered.
SO(URCE)/I(INPUT) source-name
This command provides the source with default values for RA, DEC, EQUINOX, coordinate type (MEAN or APPARENT) and PROPER\?MOTION in both coordinates. The default values for all these quantities are copied from the source which is called .DEFAULT . This is the first entry in the catalogue and has its parameters set on start up.
SO(URCE)/M(ARK) Source-Name
This command reads values for RA,DEC, EQUINOX and coordinate type from the current position of the telescope: proper motions are set to zero. Thus, it provides a means to record the positions of objects with poor or unknown coordinates, as measured at the telescope. Again, the new entry in the catalogue becomes the 'edit' source.
Error checks are made to see if the source-name is already in the catalogue; whether the maximum number of catalogue entries has been exceeded; whether the storage allocated to the dictionary of source-names has been filled; or whether the name of the source is too long. If the source name does already exist the entry is simply overwritten without error message. Otherwise, appropriate messages are displayed in each case and no catalogue entry is made.
STOP
STOP
is the equivalent of the T/S Dome STOP button on the control panel. It stops both the telescope and the dome. There are no qualifiers.
TELESCOPE
T(ELESCOPE)/O(VER\?POLE) I<>(INT default)T(ELESCOPE)/U(NDER\?POLE) (INT not enabled)
T(ELESCOPE)/E(AST) (JKT)
T(ELESCOPE)/W(EST) (JKT)
is used to set the mode of telescope operation according to the qualifier; i.e. working either East or West of the pier on JKT with E(AST) as default. On the INT, OVER is the default and UNDER\?POLE is NOT enabled.
TITLE
TI(TLE)
is only used for input from files. The text following the command is printed on the terminal. It is used for instance to output the initial messages for the user interface. There are no qualifiers.
TRAIL
TR(AIL)/ALL duration length angleTR(AIL)/D(URATION) duration (secs)
TR(AIL)/L(ENGTH) length (arcsecs)
TR(AIL)/A(NGLE) position-angle (degrees)
sets up the parameters for a trail on the sky to be followed by the telescope. The trailing is activated by pushing the associated buttons under SCAN/TRAIL near the centre of the System Control panel (see below). The starting position is where the telescope happens to be at the time the TRAIL begins; thus, its definition is relative to the starting point; there is no offset to a central position.
Note that the default mode is TRAIL, with the SCANTRAIL button unlit. (SCAN is a command very similar to TRAIL; if the SCAN mode is selected this button lights up. In SCAN mode you are supposed to be able to make a series of parallel trails, in order to scan an area of sky; this command has, however, not yet been commissioned.)
A TRAIL is performed as follows:-
TURNTABLE
TU(RNTABLE) position angle (degrees)
sets the required rotator position at Cassegrain. The turntable will be driven to this position when the TURNTABLE NOM button on the control desk is pressed. There are no qualifiers. Note that it has a synonym, ROTATOR.
ZEROSET
is used to zeroset the incremental encoders.
Z(EROSET)/A(UTO)
sets the incremental encoder readings to zero when the telescope slews past a hardware marker. The sequence of operations is:
Warning: this command is not yet fully debugged. It can be used when the
hardware zeroset is broken. In this case, move the telescope to the
zeroset position at the zenith (HA = 0; Dec = latitude) as indicated by
the synchros (INT) (or setting circles at the JKT) and enter Z(EROSET)/M(ANUAL).
This effectively does a SNAFU operation assuming that the telescope is
at the zeroset position. The result will be significantly less accurate
than the standard hardware zeroset. See section for more
information.