WHT Autoguider Network Messages

Philip Taylor, Bruce Gentles & Jonathan Burch

12th August 1996

Introduction

This document describes the set of utility network messages that the WHT autoguider and system computer will use to communicate with each other, which has been agreed upon after several discussions involving various people. The format of the messages resembles the 4MS 'standard' as far as is practicabe. In this document the term 'instrumental magnitude' refers to the magnitude measured by the autoguider, but with the effect of the autoguider filter taken out with an offset.

Command codes

The following command codes are recognised by the Autoguider micro software :

101 - Requests autoguider action with associated parameters.

200 - Immediate status return for specified Autoguider function.

201 - Delayed status. Status returned when the current requested autoguider function is completed.

Status Message codes

Status messages issued by the 4MS are identified by prefix codes of the form 8** ( MON800, fofr example ), whoses meanings are defined in the doeument ER412. The following summary gicves an outline of the mesage types issued by the $ms and how they are affected by the level of monitor mode enabled.

800 - Immediate status message issued to a node in response to an imemdiate status request ( code 200) from that node.

801 - Delayed staus message issued to a node in response to a delayed status request ( code 201) from that node.

802 - Unexpected change notification issued to any node that has monnitor mode enabled ( level 1 or 2 , set with the MON101 command ), if the 4MS detects a change that was not the result of a network command.

803 - Initiation message issued to any node that has monnitor mode enabled ( level 1 or 2 , set with the MON101 command ), at the beginning of an operation which takes an appreciable length of time to complete. Operations involving the movement of physical mechanisms tend to fall into this category , whereas those that simply resuly in a bit of processing withint the 4MS do not. Any node that has level two of monitor mode enabled will get a stream of these messages for the duration of these time consuming operations.

804 - Completion message issued to any node that has monnitor mode enabled ( level 1 or 2 , set with the MON101 command ) on completion of any command except one of the standard functions which are executed synchronously.

Command Error and State Values

The command state returned will adhere to the ER412 standard -

8016 TSKACTIV task active

The command errors returned will be from the following set

0216 OUTRANGE Parameter out of range

0416 BADFRMAT Invalid format

0516 LISTFULL Monitor node list full.

Mechanism Error Status Values

0116 CCDRDERR Error reading CCD

0216 BADSRANK Bad star rank number

0316 STARSLOW Less than N stars in window

0416 BADWNDSZ Bad window size

0516 NOGDSTAR No guide star tagged

0616 GALREADY Guiding already on

0716 GDNOWOFF Guiding already off

0816 SIGNLLOW Signal low warning

0916 GSUSPEND Guiding suspended due to low signal level

0A16 BADNFIB Bad fibre number value

0B16 WOVRLAP Window overlap

0C16 2ROACTV more than on window being read out.

0D16 BADFMOD Bad Fibre update mode value

0E16 GDFIBRE Fibre currently used for guiding.

1016 BADSGUI Bad guiding state value

1116 BADNGUI Bad guiding packet integrations value

1316 CCDEDGE Guide star has reached edge of CCD

1416 BADTAU Requested integration time out-of-range

1516 BADMZERO Bad magnitude zero point

1616 BADTLVAL Bad tolerance value specified

1716 CCDHANG CCD Controller not responding

1816 CCDWARM CCD Temperature high

1916 NOAPPFUN Function not available for this application

1A16 NOFIBRES No fibres selected

1B16 BADNCEN Bad number of AF2 centroids

1C16 DICIOFL CCD data overflow

1D16 DICIBER CCD data Bus error

1E16 PIXMISS CCD pixels missing

1F16 DICICER DICI command error

2016 CRUNNING Continuous readout loop still running

2116 CNOWOFF Continuous readout loop now off

2216 LHUNG Continuous readout loop failed to exit normally

2316 LTOOFAST Loop time too fast for window/integration

2416 CRMTOUT Continuous readout mode loop timeout

2916 HNOTCON CCD controller not connected.

Commands

APP - select the autoguider application.

  1. APP101(na)
    1. Select specified autoguider application.
    1. na - one-digit decimal integer, autoguider application to be selected. Application numbers as follows :
      0 = Cassegrain
      1 = UES
      2 = Prime focus
      3 = AutoFib
      4 = Ghril
      5 = Integral
  2. APP200/201
  3. APP800/801/803/804(eec,eem,na,nv)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      na - as above
      nv = ascii string, micro code version string. E.g. V4.0.2a ( Max length 40 chars. )

ATG - Autoguide: find a guide star and start the guide loop.

  1. ATG101(nb)
    1. This command does the equivalent to FLD101(nb) SEL101(nb) GUI101(1). It reads out the CCD, finds the nb brightest stars and starts guiding on the least brightest found. To guide on the brightest star, set nb to 1, and only one star will be searched for.

The operation of the command is dependent on the configuration selected with the APP command, as described in Table 1 below.

Table 1 - Operation of ATG command with different configurations

Cassegrain Whole field is searched. Least brightest chosen    
           to guide on.                                       

UES        Search slit probe and guide on slit star image.    

Prime      Search probe area. Least brightest chosen to       
           guide on                                           

AutoFib    Search Fixed probe. Least brightest chosen to      
           guide on.                                          

Ghril      As Cassegrain.                                     

Integral   Search fibre A / fibre #1. Least brightest chosen  
           to guide on                                        


nb - one-digit decimal integer, required guide stars rank in the starlog.

  1. ATG200/201
  1. ATG800/801/803/804(eec,eem,nb,x*,y*,x,y,min,m*,sgui)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      nb - as above
      x* - three-digit decimal integer, CCD x pixels; x coordinate of the star centroid
      y* - three-digit decimal integer, CCD y pixels; y coordinate of the star centroid
      x - three-digit decimal integer, CCD x pixels; recommended adjustment in x
      if the star falls on a defect.
      y - three-digit decimal integer, CCD y pixels; recommended adjustment in y
      if the star falls on a defect.
      min - two-digit decimal integer, seconds , recmmended minimum integration time to be
      used when guiding.
      m* - four-digit decimal integer, hundredths of a magnitude, instrumental magnitude of the star.

CEN - read out fibre window and centroid.

  1. CEN101(rmode, int, ncent)
    1. This command is only valid when the AutoFib configuration is selected. Switch to the fibre specified by nfib, if necessary. Read out the fibre ncent times. For each window read out, extract the window defined by the CWN command and centroid this image. Calculate the average of the centroids, fwhm and magnitudes. If the guide loop is active, it will be suspended whilst this command is running. After the command finishes, guiding should be restored as before. The TCS will be informed of the time needed for this command so that it does not drop out of its 'autoguide' mode. Either the whole fibre, or just the centroid window is read out and displayed.
    1. rmode - one-digit decimal integer, readout mode, 0 rmode 1 modes are:
      0 = readout & display whole fibre; centroid window defined by CWN command
      1 = readout, display and centroid only the window defined by the CWN command
      int - five digit decimal integer, milliseconds, 50 int 50000
      ncent - two digit decimal integer, number of centroids to average
  2. CEN200/201
  3. CEN800/801/803/804(eec, eem, fwhmcen, magcen, xcen, ycen, ncen, int, ncent, ncurr)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      fwhmcen - four digit decimal integer, averaged full width half maximum of the star images.
      magcen - four digit decimal integer, averaged stellar magnitude of the centroided stars.
      xcen - four digit decimal integer, microns from fibre centre, average x centroid.
      ycen - four digit decimal integer, microns from fibre centre, average y centroid.
      ncen - one-digit decimal integer, fibre index, 4 nfib 5; fibre being centroided.
      int - as above
      ncent - as above
      ncurr - two digit decimal integer, number of centroids performed so far.
      1. CCDRDERR
        BADNFIB
        SIGNLLOW
        BADTINT
        CCDHANG
        CCDWARM
        NOAPPFUN
        CCDEDGE

CTA - start or stop displaying currently configured CCD windows.

  1. CTA101(scta)
    1. The CTA command starts or stops the ConTinuous Acquisition loop. This will read out the currently configured CCD windows and display them. When starting the acquisition loop, if the guide loop is running, the CTA command will abort with error status.

Table 2 Operation of CTA command with different configurations

Cassegrain Whole field is read out & displayed.               

UES        Windows defined by GDM mode read out & displayed.  

Prime      Probe area read out & displayed.                   

AutoFib    Windows defined by GDM mode read out & displayed.  

Ghril      Whole field is read out & displayed.               

Integral   Windows defined by GDM mode read out & displayed.  


At Cassegrain, the whole CCD is read out.
At UES, those fibres in the display list ( see GDM ) are displayed.
At Prime focus, the Guide fibre is read out.
At AF2, those fibres in the display list ( see GDM ) are displayed.
At Ghril, the whole CCD is read out.
At Integral, those fibres in the display list ( see GDM ) are displayed.

  1. scta - one digit decimal integer, desired loop state, 0=off 1=on.
  1. CTA200/201
  2. CTA800/801/802/803/804(eec, eem, scta)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      scta - one digit decimal integer, current loop state, 0=off 1=on
      1. CENRUNN
        CCDRDERR
        CCDHANG
        CCDWARM
        LHUNG

CRC - display cursor relative to fibre or chip centre

  1. CRC101(xccur,yccur)
    1. CRC draws the graphics cursor at position xccur yccur on the CCD image, relative to the CCD centre ( cass, Ghril ) or current fibre centre ( UES, AF2, Prime ) . It can be used to visually confirm the results of another operation. Note that the FLD, CEN, GUI, CTA commands will also draw the graphics cursor at various places on the CCD image during their normal operation.
    1. xccur - three digit decimal integer, x coordinate of cursor position. -200 xcur 200
      yccur - three digit decimal integer, y coordinate of cursor position. -144 ycur 144
  2. CRC200/201
  3. CRC800/801/803/804(eec,eem,xccur,yccur)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      xccur - as above
      yccur - as above

CRO - display cursor relative to CCD origin

  1. CRO101(xcur,ycur)
    1. CRO draws the graphics cursor at CCD pixel position xcur ycur. xcur ycur are relative to the CCD chip origin. It can be used to visually confirm the results of another operation. Note that the FLD, CEN, GUI, CTA commands will also draw the graphics cursor at various places on the CCD image during their normal operation. CEN101(0,0) will put the cursor at the lower left hand corner of the CCD image and turn it off.
    1. xcur - three digit decimal integer, x coordinate of cursor position. 0 xcur 399
      ycur - three digit decimal integer, y coordinate of cursor position. 0 ycur 287
  2. CRO200/201
  3. CRO800/801/803/804(eec,eem,xcur,ycur)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      xcur - as above
      ycur - as above

CME - clear all mechanism errors

  1. CME101
    1. clears the mechanism error variable for all network commands. This allows the autoguider to be brought to a known state, so that when a XXX200 immediate status request is issued ( usually from an OBEYW ) previous operations can be ignored and not affect expected porocedure operation. ( This is to get round the problem of OBEYW calls failing due to an error status left lying around, for example the SIGNLLOW or GSUSPEND or CCDHANG error left from the last time a command was run. The error may have been cleared by running another command but the error status is retained with the command which was running when the error occured. )
    1. none
  2. CME200/201
  3. CME800/801/803/804(eec, eem)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      1. none

CWN - Autofib centroid window position

  1. CWN101(Nfib,x1,y1,x2,y2)
    1. CWN defines the area within the AutoFib fibre where the centroid is performed. The default set with the APP command is the whole fibre area. During the CEN command, a window within the fibre is extracted and the centroid performed there, in order to speed up operation and make the centroid more accurate. Noise and background sky signal may swamp a centroid performed on too large a window.
      (x1,y1) defines the bottom left hand corner of the window relative to the fibre centre.
      (x2,y2) defines the top right hand corner of the window relative to the fibre centre.
    1. nfib - one digit decimal integer, probe fibre , 0 nfib 1 Fibre indexes defined as follows:
      4 = Fixed fibre 5 = mobile fibre
      x1 two digit decimal integer, distance to left hand window edge, 10 x1 99
      y1 two digit decimal integer, distance to bottom window edge, 10 y1 99
      x2 two digit decimal integer, distance to right hand window edge, 10 x2 99
      y2 two digit decimal integer, distance to top window edge, 10 y2 99
  2. CWN200/201
  3. CWN800/801/803/804(nfib,x1,y1,x2,y2)
    1. returns the centroid window definition and the fibre for which this refers
    1. nfib - as selected by the
      y1 - as above
      x2 - as above
      y2 - as above

DAP - Calculate dark current noise pattern for current CCD

  1. DAP101
    1. DAP averages 10 full frame exposures of 0 mS integration time and 10 exposures of 10 second integration time. From these images, the static CCD readout pattern and the integration time component are calculated and stored to disk. These are removed from each CCD frame read out during the FLD CTA CEN and GUI commands. Note that the EXP command does not remove dark current from the CCD image.
    1. none
  2. DAP200/201
  3. DAP800/801/803/804(eec, eem, nhead)
    1. Informs the system computer or any node with monitor mode enabled of the activity of this command.
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      nhead - one digit decimal integer, ccd head number. 0 nhead 4 as follows:
      0 = Cassegrain
      1 = UES
      2 = Prime Focus
      3 = AutoFib
      4 = Ghril
      1. CCDRDERR
        CCDHUNG

EXP - expose CCD

  1. EXP101(exp)
    1. Exposes the current CCD for exp mS and displays the full frame readout without any processing. ( The image is left in data collection area #0 for any processing from the Engineering console. )
    1. exp - five digit decimal integer, milliseconds, Exposure time. 50 exp 50000
  2. EXP200/201
  3. EXP800/801/803/804(eec, eem, exp, cur)
    1. Reports the status of the EXP command.
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      exp - as above
      cur - five digit decimal integer, milliseconds since exposure started
    2. CCDRDERR
      CCDHUNG

FIB - define or read window variables

  1. FIB101(Fmode,Nfib,dx,dy,x0,y0)
    1. Sets, reads or resets the appropriate window variables. All of the positions of readout windows are defined in a single array, these windows are known either as windows or fibres as appropriate. A fibre image definition is treated simply as the box which is read form the CCD to see the fibre. These definitions area not fixed, but may be changed on-line within the CONFIG engineering menu. To enable the system computer to know the current configuration, this command allow the current fibre variables to be set, read, or reset to the defaults read from disk, or even to overwrite the default set saved on disk. This command modifies or reads one variable quartet. The whole set of fibre definitions is stored or read from disk. When a variable set is written to, the fibre is redrawn on the display. If the continuous readout loop is active the window read out is modified to reflect the new definition.
      Note that overlapping windows are not allowed to be read from the CCD. Creating an overlap may cause unexpected effects. Do not use this command if more than one window is being read from the CCD.
    1. Fmode - one-digit decimal integer, command mode; 0 Fmode 3; modes are:
      0 = read fibre variable quartet
      1 = write fibre variable quartet
      2 = revert to variable set stored on disk
      3 = write current variables set to disk
      Nfib - one-digit decimal integer, fibre index, 0 Nfib 13; Fibre indexes are:

index name type relevant commands

  1. Tracking guide window internally generated
  2. window tracking dead area internally generated
  3. UES slit fibre ABS
  4. UES coarse fibre ABS
  5. Prime guide fibre ABS
  6. AF2 Fixed probe ABS ( FLD SAP SAW )
  7. AF2 Mobile fibre ABS ( FLD SAP SAW )
  8. Integral probe A or #1 ABS ( FLD SAP SAW )
  9. Integral probe B or #2 ABS ( FLD SAP SAW )
  10. Tracking window valid movement area ABS ( TOL )
  11. Max CCD acquisition area ABS ( SAW )
  12. CCD active pixel (underscan) area ABS
  13. Centroid extract area - Fixed probe REL ( CWN )
  14. Centroid extract area - Mobile probe REL ( CWN )
  15. internal use only
  16. internal use only
  17. internal use only
  18. Full frame CCD limits ABS
  19. Acquisition search area REL ( SAW APP)

dx - three-digit decimal integer, CCD x pixels; 1 dx 400 ; window width
dy - three-digit decimal integer, CCD x pixels; 1 dx 288 ; window height
x0 - three-digit decimal integer, CCD x pixels;
0 x0 400 for absolute -400 x0 400 for relative ; window x origin
y0 - three-digit decimal integer, CCD x pixels;
0 y0 288 for absolute -288 y0 288 for relative ; window y origin

  1. FIB200/201
  2. FIB800/801/802/803/804(eec,eem,Fmode,Nfib,dx,dy,x0,y0)
    1. returns parameters of current fibre, set with the FIB101 command
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      Fmode - as above
      Nfib - as above
      dx - as above
      dy - as above
      x0 - as above
      y0 - as above
      1. WOVRLAP
        2ROACTV
        BADWSIZ
        BADFMOD
        BADNFIB

FLD - field acquisition.

  1. FLD101(nb)
    1. This command samples the field of the autoguider probe and searches for up to nb stars in the image. All stars found are entered into a starlog, ranked by brightness. Single 'hot' pixels are ignored. Star images are removed from the image when found. If the brightest pixel in the image does not produce enough signal to noise to centroid, the search is aborted. Stars are identified primarily by position of brightest pixel. The starlog contains the coordinates of the centroid of the stars found.

Table 3 Operation of the FLD command in different configurations

Cassegrain Search area is whole CCD within underscan.         

UES        Search area restricted to area defined by GDM      
           mode.                                              

Prime      Search area is within probe field of view.         

AutoFib    Search area restricted to area defined by GDM      
           mode.                                              

Ghril      Search area is whole CCD within underscan.         

Integral   Search area restricted to area defined by GDM      
           mode.                                              


  1. nb - one-digit decimal integer, required rank of guide stars in the starlog.
  1. FLD200/201
  1. FLD800/801/803/804(eec,eem,x*,y*,x,y,min,m*)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      x* - three-digit decimal integer, CCD x pixels; x coordinate of the star centroid
      y* - three-digit decimal integer, CCD y pixels; y coordinate of the star centroid
      x - three-digit decimal integer, CCD x pixels; recommended adjustment in x
      if the star falls on a defect.
      y - three-digit decimal integer, CCD y pixels; recommended adjustment in y
      if the star falls on a defect.
      min - two-digit decimal integer, seconds , recmmended minimum integration time to be
      used when guiding.
      m* - four-digit decimal integer, hundredths of a magnitude, instrumental magnitude of the star.
      1. ccdrderr
        badsrank
        starslow
        badwndsz
        ccdwarm
        ccdhung

FLO - CCD head flush rate

  1. FLO101(ilock,thresh)
    1. This command enables or disable the interlock which stops the cooling of the CCD if the dry Nitrogen flush rate falls below the threshhold value.
    1. ilock - one-digit decimal integer, desired interlock state; 0 ilock 1 ;
      1 = interlock enabled, 0 = interlock disabled
      thresh - six-digit decimal integer, ml per hour; flow rate threshold
  2. FLO200/201
  3. FLO800/801/803/804(eec,eem,ilock,thresh,rate)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      ilock - one-digit decimal integer, desired interlock state; 0 ilock 1 ;
      1 = interlock enabled, 0 = interlock disabled
      thresh - six-digit decimal integer, ml per hour; flow rate threshold
      rate - six-digit decimal integer, ml per hour; current flow rate

GDM -select Guide Mode

  1. GDM101(umode)
    1. The Guide mode defines which of the fibres in multi fibre configurations are to be use for acquisition and guiding and which fibres are to be used as auxiliary displays.

One fibre is nominated as the "guide" fibre. The field command will search for stars within the area of that probe since the acquisition window is set to be within the guide fibre. As a result, the starlog will contain stars from that fibre and they will be used in the guide loop.

When the guide loop is active, it is possible to switch between modes as long as those modes have the same guide fibre. Thus starting and stopping display of the other fibre is possible without interrupting the guide loop. If the guide loop is active and a mode is requested which does not retain the same guide fibre, the command aborts with BADFMOD error status. The mapping between modes and configurations is shown in Table 4.

Table 4 Guide modes for each configuration

Configurati gdmode    description                                
on                                                               

Cassegrain  -         Command not available. (camera not fibre   
                      fed.)                                      

UES         1         search slit,  display slit,  guide on      
                      slit.                                      

            2         search XY probe, display XY probe guide    
                      on XY probe                                

            3         search slit,  display both  guide on slit  

            4         search XY probe, display both guide on XY  
                      probe                                      

Prime       -         Command not available. (only one fibre so  
                      one mode)                                  

AutoFib     1         search fixed,  display fixed   guide on    
                      fixed                                      

            2         search mobile, display mobile guide on     
                      mobile                                     

            3         search fixed,  display both  guide on      
                      fixed                                      

            4         search mobile, display both guide on       
                      mobile                                     

Ghril                 Command not available. (camera not fibre   
                      fed.)                                      

Integral    1         search #1,  display #1  guide on #1        

            2         search #2, display #2 guide on #2          

            3         search #1,  display both  guide on #1      

            4         search #2, display both guide on #2        


umode - one-digit decimal integer, guide mode; 1 umode 4; modes as defined in Table 4:

  1. GDM200/201
  2. GDM800/801/803/804(eec,eem,umode)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      umode - as above
      1. BADFMOD

GLP - set number of guide centroids to average

  1. GLP101(nglp)
    1. sets the number of guide loop centroids to average per output to the TCS. Each output is the average of the next nglp centroids.
    1. nglp - one-digit decimal integer, number of centroids; 1 nglp 100
  2. GLP200/201
  3. GLP800/801/803/804(eec,eem,nglp)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      nglp - as above

GUI - start or stop the guide loop

  1. GUI101(sgui)
    1. starts or stops the guide loop. The guide loop takes the coordinates of the currently selected star in the current starlog, and starts a loop which reads out a window of the current guide window size. The image from this guide window is centroided and the result sent to the TCS every nglp loops. See also GDM GLP WSZ SEL FLD . The window will track the star across the CCD if it moves, this feature can be disabled with the TRA command. The tracking is disabled by default for the UES configuration.

Multiple windows may be read out, depending on the guide mode. All windows read out are centroided. The guide mode also defines which one of these will be nominated as the guide window, its centroid is passed to the TCS via a serial line.

  1. sgui - one-digit decimal integer, desired loop state ; 0 sgui 1
  1. GUI200/201
  2. GUI800/801/802/803/804(eec,eem,nglp,nfib,nlog,nstar)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      nglp - as above
      nfib - af2 or UES fibre
      nlog - af2 current log
      nstar - currently selected star

HED - select autoguider ccd camera.

  1. HED101(nhead)
    1. selects the desired ccd camera head. This will involve using the appropriate serial port for communication and the appropriate CCD controller. At AF2, the Prime controller is used via the Prime focus port. The CCD controller is re-initialised. Only one controller can be accessed at once.
  2. nhead - one-digit decimal integer, head number; valid head numbers are:

Head        CCD Camera head      connected   VME rack          
number      name                    via      connector         

0           Cassegrain           cass port   (SP2, first       
                                             card)             

1           UES                   ues port   (SP3, first       
                                             card)             

2           Prime                prime port  (SP4, first       
                                             card)             

3           AF2                  prime port  (SP4, first       
                                             card)             

4           Ghril               ghril port   (SP1, second      
                                             card)             

5           Integral            ghril port   (SP1, second      
                                             card)             

6           LPO lab/spare head   cass port   (SP2, first       
                                             card)             

7           Cambridge lab head   cass port   (SP2, first       
                                             card)             



  1. HED200/201
  2. HED800/801/803/804(eec,eem,nhead,nport)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      nhead - as above
      nport - one-digit decimal integer, port number; port numbers as for head numbers.

INT - set integration time

  1. INT101(int)
    1. sets the system integration time used for CTA GUI and FLD commands
    1. int - five-digit decimal integer, milliseconds; 50 int 50000
  2. INT200/201
  3. INT800/801/803/804(tint)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      int - as above

LOG - report starlog information

  1. LOG101(nlog)
    1. The starlog records the results of the FLD field search command in the form of a list of CCD coordinates ordered by brightness.
      At Cass, UES Prime and Ghril, only one starlog exists, nlog = 0.
      At AF2, there are two starlogs, one for each of the probe fibres. up to nlog starlog entries are reported, the rest are null.
    1. nlog - one-digit decimal integer, number of entries to report; 1 nlog 8
  2. LOG200/201
  3. LOG800/801/803/804(eec,eem,nlog,nfound,nsel,nfib)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      nlog - as above
      nfound - one-digit decimal integer, valid stars found by FLD command
      nsel - one-digit decimal integer, currently selected star
      nfib - one-digit decimal integer, currently selected fibre

MAG - Filter magnitude correction

  1. MAG101(mc)
    1. This command specifies the correction factor added to the instrumental magnitude to get the stellar magnitude, and compensates for the effect of the autoguider filter.
    1. mc - three-digit decimal integer, .001 magnitude; 0 mc 999
  2. MAG200/201
  3. MAG800/801/803/804(eec,eem,mc)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      mc - as above

MON - monitor mode

  1. MON101(sm)
    1. sets sm the monitor mode level.
    1. sm - one-digit decimal integer, request for sm; 0 sm 2
      0 = monitor mode disabled
      1 = level 1 monitor mode enabled ( see section 3 )
      2 = level 2 monitor mode enabled ( see section 3 )
  2. MON200
  3. MON800(eec,eem,sm)


  4. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
    eem- two digit hexadecimal bit mask, 'mechanism error code'
    sm - as above.
    1. LISTFULL

PEL - enable peltier cooling of CCD

  1. PEL101(spel)
    1. sets the required cooling state of the electronic peltier cooler used to cool the CCD to around -40C. The autoguider loads with cooling turned off.
    1. spel - one-digit decimal integer, required state, 0 spel 1; 0=off/warm 1 = on/cool
  2. PEL200/201
  3. PEL800/801/803/804(eec,eem,spel,temp,nhed)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      spel - as above - current state
      temp - four-digit decimal integer, 0.1C; -50.0 temp +20.0
      nhed - one-digit decimal integer, current CCD camera head, 0 nhed 4

PLO - set guide error plot parameters

  1. PLO101(smag,stime)
    1. sets the scales for error magnitude and time for the plot of guide errors versus sample mumber on the autoguider display. The error is in multiples of 0.1,0.2 or 0.5 ArcSeconds full scale each side of the axis, and the time display is in numbers of guide samples per output point. The plot is 256 points long.
    1. smag - one-digit decimal integer, scale index; 0 smag 8, the index corresponds to
      0 1 2 3 4 5 6 7 8
      0.1 0.2 0.5 1 2 5 10 20 50
      stime - two-digit decimal integer, samples; 1 stime 10; number of samples per plot point.
  2. PlO200/201
  3. PLO800/801/803/804(eec,eem,smag,stime,xmin,ymin,xmax,ymax)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      smag - as above
      stime - as above
      xmin - minimum value of x error plotted
      ymin - minimum value of y error plotted
      xmax - maximum value of x error plotted
      ymax - maximum value of y error plotted

RES - reset the autoguider and reload the software from disc

  1. RES101
    1. this command aborts all current operations and reload the system from disc. It currently is not operational, The status return is currently operational.
    1. none
  2. RES200/201
  3. RES800/801/803/804(eec,eem,tres)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      tres - six-digit decimal integer, seconds , time since last reload.

SAW - set Acquisition window ( field search area )

  1. SAW101(x1,y1,x2,y2)
    1. sets the field search area. Defaults to the largest possible area when the APP command is executed. (x1,y1) are the coordinates of the bottom left window edge relative to the fibre or chip centre. (x2,y2) are the coordinates of the top right window edge relative to the fibre or CCD centre. Precise parameter limits are sensitive to the application and fibre position & size. The FLD command will look inside this box for stars.
      At Cass and Ghril the whole chip is available.
      At UES this command is not available
      At AF2 this command applies to the current acquisition probe fibre - see SAP
    1. x1 - three-digit decimal integer, CCD x pixels; -200 x1 +200
      y1 - three-digit decimal integer, CCD y pixels; -144 y1 +144
      x2 - three-digit decimal integer, CCD x pixels; -200 x2 +200
      y2 - three-digit decimal integer, CCD y pixels; -144 y2 +144
  2. SAW200/201
  3. SAW800/801/803/804(eec,eem,nfib,x1,y1,x2,y2)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      nfib - one-digit decimal integer, currently selected probe fibre
      x1 - as above
      y1 - as above
      x2 - as above
      y2 - as above

SEL - select guide star from starlog

  1. SEL101(nstar)
    1. Selects a star from the starlog to use as the guide star. Changes to this star if the guide loop is active. At Cass, Prime, Ghril, starlog 0 is used. At AF2, the currently selected acquisition fibre starlog , selected with SAP, is used. The FLD SEL GUI commands all use the same starlog.
    1. nstar - one-digit decimal integer, 1 nstar 8
  2. SEL200/201
  3. SEL800/801/803/804(eec,eem,ncen)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      ncen - as above

STA - reset or report statistics on guide errors

  1. STA101
    1. The STA101 command resets the statistics on the guiding process. The STA status request reports the current guiding statistics.
    1. none
  2. STA200/201
  3. STA800/801/803/804(eec,eem,nsta,sx,sy,dsx,dsy,mag,dmag)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      nsta - five-digit decimal integer, number of valid samples in guide buffer
      sx - three-digit decimal integer, hundredths of arcsecond; Mean seeing fwhm in x
      sy - three-digit decimal integer, hundredths of arcsecond; Mean seeing fwhm in y
      dsx - three-digit decimal integer, hundredths of arcsecond; variance in sx
      dsx - three-digit decimal integer, hundredths of arcsecond; variance in sy
      mag - three-digit decimal integer, hundredths of arcsecond; Mean instrumental magnitude
      dmag - three-digit decimal integer, hundredths of arcsecond; variance in mag

TOL - tolerance for variable quantities

  1. TOL101(s-,s+,ns,m*-,m*+,nm*,p*)
    1. Sets the tolerances for the seeing; the variation of the instrumental magnitude of the guide star; and the guide star's proximity to the edge of the CCD's area. This is a utility function that delivers a mode message if any of these quantities strays outside a range that can be defined by the system computer.
    1. s- - four-digit decimal integer, of an arcsecond;
      lowest acceptable value for the mean FWHM.
      s+ - four-digit decimal integer, of an arcsecond;
      highest acceptable value for the mean FWHM
      ns - five-digit decimal integer; number of samples over which the seeing is averaged
      (this may be one).
      m*- - three-digit decimal integer, thousandths of a magnitude;
      lowest acceptable value for the rms variation in the instrumental
      magnitude of the guide star.
      m*+ - three-digit decimal integer, of a magnitude;
      highest acceptable value for the rms variation in the instrumental
      magnitude of the guide star.
      nm* - five-digit decimal integer, number of samples over which the variation in the instrumental
      magnitude of the guide star is averaged (this may be one).
      p* - two-digit decimal integer, pixels; smallest acceptable number of pixels between the guide
      star and an edge of the CCD's or fibres' imaging area.
  2. TOL200/201
  3. TOL800/801/802/803/804(s-,s+,ns,m*-,m*+,nm*,p*,Ftol)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      s- -
      s+ -
      ns -
      m*- - as above
      m*+ -
      nm*
      p*
      Ftol - one-digit hexadecimal bit-mask, tolerance flags. A monitor mode message is delivered
      if any of the bits changes. Each bit has the following significance if set:
      0 = s- has been transgressed
      1 = s+ has been transgressed
      2 = m*- s- has been transgressed
      3 = m*+ s- has been transgressed
      4 = p*s- has been transgressed
      1. BADTLVAL

TRA - enable / disable tracking of guide window.

  1. TRA101(stra)
    1. sets whether or not the guide window is allowed to track the star if it moves away from the centre of the guide window. Not available at UES. This facility is useful in bad seeing.
    1. stra - one-digit decimal integer, desired tracking state; 0 stra 1
      0 = tracking disabled. 1 = tracking enabled
  2. TRA200/201
  3. TRA800/801(eec,eem,stra)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      stra - as above

WMO - move the guide window to a given position on the CCD.

  1. WMO101(wref,xc,yc)
    1. WMO moves the tracking guide window to a predermined place on the CCD chip. This must be within the tolerances set by the TOL command. This is useful for manually offsetting the telescope and having the autoguider follow without having to re-acquire a guide star. The parameters are either relative to the fibre/CCD centre or to the CCD origin. The outer limits are used for command error checking, the area of the CCD where the guide window would track is used within the application code.
      WMO may be used after SEL, or instead of SEL, to start the guide loop at a pre-determined place. To achieve this, WMO must be issued directly before the GUI101(1) command.
    1. wref - one-digit decimal integer, coordinate reference, 0 wref 1;
      0=from CCD origin, 1=from Fibre/CCD centre.
      xc - three-digit decimal integer, x CCD pixel. 21 xc 386 when wref=0
      -179 xc 186 when wref=1
      yc - three-digit decimal integer, y CCD pixel. 10 xc 277 when wref=0
      -134 xc 133 when wref=1
  2. WMO200/201
  3. WMO800/801/803/804(eec,eem,wref,xc,yc)
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      wref - mode used in last operation of the command.
      xc - as above
      yc - as above

WSZ - set guide window size

  1. WSZ101(wsize)
    1. Sets the desired size for the guide window. The window is square, of length wsize on each size. If the guide loop is running, the active window is modified. Not available at UES.
    1. wsize - one-digit decimal integer, CCD pixels ; 10 wsize 100
  2. WSZ200/201
  3. WSZ800/801/803/804
    1. eec - two digit hexadecimal bit mask, busy bit and 'command errors'
      eem- two digit hexadecimal bit mask, 'mechanism error code'
      wsize - as above

Document History

V1.0    9th March   1989    Original issued version (JMB).                  

V1.1    15th January 1993   Detailed amendments by Philip Taylor            

V2.0    20th January 1993   Extra mnemonics, error codes to conform with    
                            new version of Autoguider micro software        

 V2.1   29th January 1993   Further mnemonics and revised errors            

V3.1    15 July 1994        Major revisions and additions by Bruce Gentles  
                            and Jonathon Burch for AutoFib                  

V4.0    9 August 1996       ABG: Additions to HED and APP commands for      
                            INTEGRAL configuration. replaced UMO and SAP    
                            and SCP commands by the GDM command to follow   
                            actual Af2 implementation.