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Telescope
SMU
SMU control parameters

The SMU parameters and their default values are to be seen at

   /jac_sw/itsroot/src/smu/XML/SMUinit.xml
Some of these will change as observing proceeds, eg the focus offsets DX, DY, DZ, and some will be changed occasionally, eg, following adjustments, the various OFFSETs, but many are essentially constant specifications of the secondary mirror hardware : eg the many SCALEs. The list below is of the 191 parameters used by the SMU task, and (the first few words of) a description of each parameter.

The actual values may have changed since this version.
Notes regarding those parameters marked with a * - especially notes re sign conventions - follow the table.

   Parameter      Default  Help
   -------------  -------  ------------------------------------------------------
   ABORT_CHOP_EW   NO     'Chop East-West axis abort state: YES = abort, NO = ena
   ABORT_CHOP_NS   NO     'Chop North-South axis abort state: YES = abort, NO = e
   ABORTCHOP_WAIT  2.0    'Delay [sec] between enabling chop axes and applying po
   APPLY_TEMP_CORR TRUE   'If true then apply temperature corrections to the Z fo
   AZ_RESPONSE     1.0    'AZ_Chopper static/dynamic response coefficient.'
   BEAM            'R'    'Beam for offsetting the telescope.'
   BLANK_TIME       0     'Chopper blanking time in millisecs.'
   BUS_1            3     'IEEE bus number to which XYZ device is attached.'
   BUS_2            3     'IEEE bus number to which CHOPPER device is attached.'
   CHOP_INTERVAL    1     'SM Chopper update interval [seconds].'
   CHOP_MONITOR    NO     'SM Chopper monitoring flag.'
   CHOP_THRESHOLD  1.0    'Threshold for following the rotation of the field [arcs
   CHOP_TRACKING    0     '0=Not chop_tracking, 1=chop_tracking.'
   COORDS         'AZ'    'Coordinate system for chopping.'
   DX              0.0    'X table user offset [mm].'     
   DY              0.0    'Y table user offset [mm].'
   DZ              0.0    'Z table user offset [mm].'
   DZT_COEFF      0.070   'Z linear temperature correction coefficient [mm/K].'
   DZT_CONST      -0.24   'Z linear temperature correction constant term [mm].'
   EL_RESPONSE     1.0    'EL_Chopper static/dynamic response coefficient.'
   ELEVATION_DEG  45.0    'Elevation [degrees].'
   ENABLE_TABLESW   1     'Time interval between checking tables have initialised
   EW_AMPL_SCALE  1.0E-02 'AZ chopper amplitude scale factor [arcsec per encoder u
   EW_AMPL_SLOPE  1.3413E-02  'AZ chopper amplitude slope factor [arcsec per encoder u
   EW_AMPL_CORR   9.81E-03    'Correction factor to apply to EW amplitude'
   EW_PHASE_SCALE 0.087890625 'East/West chop phase scale factor [degree per firmware
   EWAMP          60.0     'East-west chop amplitude in SM units [arcsec].'
   EWOFF           0      'East-west offset or tilt [arcsec].'
   EWPHASE         0      'East-west phase [degree].'  
   FE_TASK      'DISABLE' 'Frontend task name.'
   FREQ_LIMIT     4.0     'Cutoff frequency for chopper scale determination [arcse
   FREQUENCY      7.8125  'Chopper frequency [Hz].'
   FTS_X_OFFSET    0.0    'X focus offset of FTS from nominal position'
   FTS_Y_OFFSET    0.0    'Y focus offset of FTS from nominal position'
   FTS_Z_OFFSET    0.0    'Z focus offset of FTS from nominal position'
   FTS_1_X_OFFSET  -0.6   'X focus offset of FTS_1 (port 1) from nominal position
   FTS_1_Y_OFFSET  -0.61  'Y focus offset of FTS_1 (port 1) from nominal position
   FTS_1_Z_OFFSET  -3.68  'Z focus offset of FTS_1 (port 1) from nominal position
   FTS_2_X_OFFSET  0.0    'X focus offset of FTS_2 (port 2) from nominal position
   FTS_2_Y_OFFSET  0.0    'Y focus offset of FTS_2 (port 2) from nominal position
   FTS_2_Z_OFFSET  0.0    'Z focus offset of FTS_2 (port 2) from nominal position
   GO_EW            NO    'YES if want to chop East-West, NO otherwise.'
   GO_NS            NO    'YES if want to chop North-South NO otherwise.'
   IEEE_CONNECT    YES    'YES if want to use IEEE to connect to the Chopper, NO
   IEEE_CONNECT_1  YES    'YES if want to use IEEE to connect to the Tables, NO i
   INTERRUPT_CHOP   NO    'Stop chop while moving tables?'
   JIGGLE_COORDS   'AZ'   'Coordinate system for jiggling.'
   JIGGLE_DWELL     1     'The time in unit of chop period, to dwell at a jiggle p
   JIGGLE_END       1      'Index of the last jiggle offset value to be loaded.'
   JIGGLE_FILE             'Jiggle file name.'
   JIGGLE_MAX       1      'Maximum number of jiggle points in the current pattern'
   JIGGLE_SCALE    1.0     'Scaling factor for the currently loaded jiggle pattern'
   JIGGLE_START     1      'Index of the first jiggle offset value to be loaded.'
   JIGGLE_THROW   60.0     'Hypothetical chop throw used with CHOP_THRESHOLD for up
   LOCKIN_DELAY    15      'Time for the FE_TASK to achieve lockin [sec].'
   MAX_AMPL       24000    'Maximum amplitude of the chop [encoder units].'
   MAX_OFFS       24000    'Maximum offset of the chop [encoder units].'
   MAX_PHASE      4096     'Maximum phase (360 deg) of the chop function [firmware
   MAX_SET_CHOPPER  2      'Maximum number of tries to set the chopper parameters.'
   MODE             0      'Chopping mode specifing internal/external reference and
   MO_TASK    'DISABLE'    'Monitor task name'
   MPI_X_OFFSET    0.0     'X focus offset of MPI from nominal position'
   MPI_Y_OFFSET    0.0     'Y focus offset of MPI from nominal position'
   MPI_Z_OFFSET    0.0     'Z focus offset of MPI from nominal position'
   NO_DEVICES       2      ' Number of IEEE devices.'
   NOD_WAIT        0.0     'User delay for the telescope to nod [seconds].'
   NS_AMPL_SCALE  1.0E-02     'EL chopper amplitude scale factor [arcsec per encoder u
   NS_AMPL_SLOPE  1.3138E-02  'EL chopper amplitude slope factor [arcsec per encoder u
   NS_AMPL_CORR   1.36E-03    'Correction factor to apply to NS amplitude'
   NS_PHASE_SCALE 0.087890625 'North/South chop phase scale factor [deg per firmware u
   NSAMP          60.0     'North-South amplitude in SM units [arcsec].'
   NSOFF           0       'North-south offset or tilt [arcsec].'  
   NSPHASE         0       'North-south phase [degree].'
   OUTPUT_WAVE_EW 'POS'    'East/West output waveform signal from the chopper.'
   OUTPUT_WAVE_NS 'POS'    'North/South output waveform signal from the chopper.'
   PERIOD         128      'Period of the waveform [milliseconds].'
   POSANG         90.0     'Position angle of the chopper throw vector [degrees].'
  *POSOFF_EW     -2825     'Chopper Position Offset to the E/W axis [encoder unit]
  *POSOFF_NS     -2991    'Chopper Position Offset to the N/S axis [encoder unit]
   PRIMARY_1       16     'IEEE primary device address of XYZ microprocessor.'
   PRIMARY_2       15     'IEEE primary device address of CHOPPER microprocessor.
   PRINT_ERRORS    NO     'If this is set, Micro checksum info will be written to
   RX             0.0     'X focus offset of the current frontend from the nomina
   RXW_C_X_OFFSET  -0.56  'X focus offset of RXW_C from nominal position'
   RXW_C_Y_OFFSET  -0.74  'Y focus offset of RXW_C from nominal position'
   RXW_C_Z_OFFSET  -0.58  'Z focus offset of RXW_C from nominal position'
   RXW_D_X_OFFSET  -0.42  'X focus offset of RXW_D from nominal position'
   RXW_D_Y_OFFSET  -0.76  'Y focus offset of RXW_D from nominal position'
   RXW_D_Z_OFFSET  -0.84  'Z focus offset of RXW_D from nominal position'
   RXA2_X_OFFSET   -0.07  'X focus offset of RXA2 from nominal position'
   RXA2_Y_OFFSET   -0.52  'Y focus offset of RXA2 from nominal position'
   RXA2_Z_OFFSET   -0.67  'Z focus offset of RXA2 from nominal position'
   RXA3I_X_OFFSET  -0.52  'X focus offset of RXA2 from nominal position'
   RXA3I_Y_OFFSET  -0.59  'Y focus offset of RXA2 from nominal position'
   RXA3I_Z_OFFSET  -1.02  'Z focus offset of RXA2 from nominal position'
   RXB3_X_OFFSET   -0.06  'X focus offset of RXB3 from nominal position 
   RXB3_Y_OFFSET   0.56   'Y focus offset of RXB3 from nominal position'
   RXB3_Z_OFFSET   0.41   'Z focus offset of RXB3 from nominal position'
   RXB_X_OFFSET    -0.34  'X focus offset of RXB from nominal position'
   RXB_Y_OFFSET    -0.83  'Y focus offset of RXB from nominal position' 
   RXB_Z_OFFSET    -0.91  'Z focus offset of RXB from nominal position' 
   RXC2_X_OFFSET   0.41   'X focus offset of RXC2 from nominal position'         
   RXC2_Y_OFFSET   -0.95  'Y focus offset of RXC2 from nominal position'         
   RXC2_Z_OFFSET   -0.44  'Z focus offset of RXC2 from nominal position'         
   RXG_X_OFFSET    0.0    'X focus offset of RXG from nominal position' 
   RXG_Y_OFFSET    0.0    'Y focus offset of RXG from nominal position' 
   RXG_Z_OFFSET    -0.21  'Z focus offset of RXG from nominal position' 
   RXH_X_OFFSET    0.0    'X focus offset of RXH from nominal position' 
   RXH_Y_OFFSET    0.0    'Y focus offset of RXH from nominal position' 
   RXH_Z_OFFSET    0.0    'Z focus offset of RXH from nominal position' 
   SPIFI_NUREST   '345.0' 'Rest frequency for SPIFI'
   SPIFI_X_OFFSET  0.0    'X focus offset of SPIFI from nominal position'        
   SPIFI_Y_OFFSET  0.0    'Y focus offset of SPIFI from nominal position'        
   SPIFI_Z_OFFSET  0.0    'Z focus offset of SPIFI from nominal position'        
   SCUBA_CHP_CORR  1.00966  'Correction factor to the slope of the SCUBA chop scale
   SCUBA_CHP_OFFS  0.75     'Zero point offset for SCUBA chop scale calibration.'  
   SCUBA_NUREST    '230.0'  'Rest frequency for SCUBA'           
   SCUBA_X_OFFSET  -1.08  'X focus offset of SCUBA from nominal position'        
   SCUBA_Y_OFFSET  -1.03  'Y focus offset of SCUBA from nominal position'        
   SCUBA_Z_OFFSET  -5.13  'Z focus offset of SCUBA from nominal position'        
   RY               0.0   'Y focus offset of the current frontend from the nomina
   RZ               0.0   'Z focus offset of the current frontend from the nomina
   UKT14_X_OFFSET    0    'X focus offset of UKT14 from nominal position'        
   UKT14_Y_OFFSET    0    'Y focus offset of UKT14 from nominal position'        
   UKT14_Z_OFFSET    0    'Z focus offset of UKT14 from nominal position'        
   SECONDARY_1     -1     'IEEE secondary device addr of XYZ micro; -1 = not used
   SECONDARY_2     -1     'IEEE secondary device addr of CHOPPER micro; -1 = not 
   SET_TABLESW      3     'Time interval between checking tables have set [sec].' 
   START_CHOPPERW   3     'Time interval between checking chopper has started [sec
   STEP_THRESHOLD   1    'Threshold for stepping the telescope [arcsec].'        
   STOP_CHOPPERW    3    'Time interval between checking chopper has stopped [sec
   SX              0.0   'X table switched offset [mm].'       
   SY              0.0   'Y table switched offset [mm].'       
   SZ              0.0   'Z table switched offset [mm].'       
   T_TASK      'DISABLE' 'Telescope task name.'      
   TEL_TASK        'TEL' 'Telescope task name.'      
   TABLES_INTERVAL  30   'Tables monitoring interval [seconds].'        
   TABLES_TRACKING   0   '0=Not tables_tracking, 1=tables_tracking.'    
   TEST_SMFGST  '8,96,0' 'Dummy reply to the Chopper SMFGST command.'   
   TEST_SMP_ST    '0'    'Dummy reply to the XYZ tables ST command.'    
   TEST_SMPSST    '0'    'Dummy reply to the XYZ tables SMPSST command.'         
   TEST_SMV_ST    '0'    'Dummy reply to the chopper ST command.'       
   TEST_SMVBST    '0000' 'SMU Chopper Simulation status data (4 Digit Hex).'     
   THROW          60.0   'Chopper throw in arc seconds (2*ampl of vibration vecto
   TILT_EW        0.0    'EW tilt of chopper [arcsec].'        
   TILT_NS        0.0    'NS tilt of chopper [arcsec].'        
   TRACKING       0      '0=Not tracking, 1=tracking.'         
   TRIPOS_EW       NO    'Centre (3-Position) chopping along East-West axis.'   
   TRIPOS_NS       NO    'Centre (3-Position) chopping along North-South axis.' 
   UPDATE_INTERVAL 15    'SM Tables update interval [seconds].'         
   USERWAVE_FILE         'Name of Userwave file containing wave amplitudes'      
   VIB_INTERVAL    30    'Chopper system monitoring interval [seconds].'         
   WAVEFORM     'SQUARE' 'Name of SM chopper waveform.'        
   WAVETYPE     'SQUARE' 'Name of SM chopper wavetype.'        
   X              0.0    'X table nominal position [mm].'      
   X_ENABLE       YES    'Enable X position control? '         
   X_SCALE     -273.756  'Number of X encoder units per millimeter.'    
   X_SLIMN        400    'X soft limit negative [encoder units].'       
   X_SLIMP        13300  'X soft limit positive [encoder units].'       
   X_TOLERANCE    3      'X encoder servo tolerance [encoder units].'   
   X_ZERO       -27.99   'Encoder zero [mm].'         
  *X2EL         30.25    'X to EL offset coefficient [arcsec/mm].'      
   XA           5.791    'X focus curve gradient [mm].'        
   XB          -5.838    'X focus curve intercept [mm].'       
   XYZ_THRESHOLD 0.01    'Fractional change in gain for updating the tables.'    
   Y             0.0     'Y table nominal position [mm].'      
   Y_ENABLE       YES    'Enable Y position control? '         
   Y_SCALE       257.02  'Number of Y encoder units per millimeter.'    
   Y_SLIMN        275    'Y soft limit negative [encoder units].'       
   Y_SLIMP        13250  'Y soft limit positive [encoder units].'       
   Y_TOLERANCE    3      'Y Encoder servo tolerance [encoder units].'   
   Y_ZERO         22.88  'Encoder zero [mm].'         
  *Y2AZ           28.0   'Y to AZ offset coefficient [arcsec/mm].'      
   YA              0.0   'Y focus curve gradient [mm].'        
   YB             3.73   'Y focus curve intercept [mm].'       
   Z              0.0    'Z table nominal position [mm].'      
   Z_ENABLE       YES    'Enable Z position control? '         
   Z_SCALE      273.817  'Number of Z encoder units per millimeter.'    
   Z_SLIMN        300    'Z soft limit negative [encoder units].'       
   Z_SLIMP        12900  'Z soft limit positive [encoder units].'       
   Z_TOLERANCE    3      'Z Encoder servo tolerance [encoder units].'   
   Z_ZERO         25.09  'Encoder zero [mm].'         
   ZA             0.54   'Z focus curve gradient [mm].'        
   ZB           -12.53   'Z focus curve intercept [mm].'       
   ZC             0.845  'Z focus curve non-linear term coefficient [mm].'       
   ZA_SCUBA       0.54   'Z focus curve gradient [mm].'        
   ZB_SCUBA       -12.4  'Z focus curve intercept [mm].'       
   ZC_SCUBA       0.845  'Z focus curve non-linear term coefficient [mm].'       
   ZA_SPIFI       0.54   'Z focus curve gradient [mm].'        
   ZB_SPIFI       -12.53 'Z focus curve intercept [mm].'       
   ZC_SPIFI       0.845  'Z focus curve non-linear term coefficient [mm].'       

Sign Conventions

  • POSOFF_EW : value 81.05 encoder units/".
    viz A change of +1000 encoder units in POSOFF_EW mimics/precipitates a change in azimuth pointing of +12.34".
    Such a change would need compensating by imposing uel = -12.34".
    There was no evidence to change this value following the FCO of Oct 2007.

  • POSOFF_NS : value 77.845 encoder units/".
    viz A change of +1000 encoder units in POSOFF_EW mimics/precipitates a change in elevation pointing of +12.85".
    Such a change would need compensating by imposing uel = -12.85".
    There was no evidence to change this value following the FCO of Oct 2007.

  • X2EL : value 30.25 "/mm viz A change of +1mm in SMU-X mimics/precipitates a change in elevation pointing of -30.25".
    Such a change would need compensating by imposing uel = +30.25".

  • Y2AZ : value 28.0 "/mm
    viz A change of +1mm in SMU-Y mimics/precipitates a change in azimuth pointing of -28.0".
    Such a change would need compensating by imposing uaz = +28.0".

Contact: Iain Coulson. Updated: Tue Dec 18 16:53:12 HST 2007

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