2.5 sdds2dfeedforward

• description: sdds2dfeedforward performs two-dimensional feedforward on process variables. It sets one or more actuators according to a predetermined function of two readback values. The user supplies tables giving the actuator value as a function of two readbacks. Each table is provided as an SDDS page containing the columns Readback1Value, Readback2Value, and ActuatorValue. Parameters Readback1Name, Readback2Name, and ActuatorName specify the corresponding process variables. Optional parameters include ReadbackChangeThreshold and ActuatorChangeLimit.
• examples: A basic invocation reads an SDDS table and applies it every ten seconds:
  sdds2dfeedforward ID1Compensation.sdds -interval=10

  where ID1Compensation.sdds might contain

  Readback1Name = ID1:X   Readback2Name = ID1:Y   ActuatorName = S1B:H1:CurrentAO  
   Readback1Value  Readback2Value  ActuatorValue  
  ------------------------------  
         150.000       0.000          0.000  
         100.000      50.000          1.000  
          50.000     100.000         10.000

• synopsis:
  usage: sdds2dfeedforward <inputfile>  
         [-controlLog=<rootname>]  
         [-interval=<real-value>] [-steps=<integer-value>]  
         [-verbose] [-dryRun] [-offsetOnly]  
         [-averageOf=<number>[,interval=<seconds>]]  
         [-advance=<seconds>]  
         [-testValues=<SDDSfile>]  
         [-runControlPV=string=<string>[,pingTimeout=<value>]]  
         [-runControlDescription=<string>]  
         [-CASecurityTest]  
         [-pendIOtime=<seconds>] [-infiniteLoop]

• files:
  • input file: An SDDS file with parameters Readback1Name, Readback2Name, and ActuatorName. Optional parameters include ReadbackChangeThreshold and ActuatorChangeLimit. Required columns are Readback1Value, Readback2Value, and ActuatorValue.
• switches:
  • interval=<real-value> — Interval in seconds between corrections.
  • steps=<integer-value> — Number of iterations before exiting.
  • verbose — Print additional information.
  • dryRun — Readbacks are read but actuators are not changed.
  • offsetOnly — Offset tables using initial readback values so no change is made until a readback moves.
  • averageOf=<number>[,interval=<seconds>] — Average multiple readings of each readback before computing corrections.
  • advance=<seconds> — Advance readback values based on their ramp rate by the given number of seconds.
  • testValues=<file> — SDDS file giving limits for PV tests that suspend feedforward when violated.
  • runControlPV=string=<string>[,pingTimeout=<value>] — Use a run-control PV and optional ping timeout.
  • runControlDescription=<string> — Description for the run-control record.
  • CASecurityTest — Check Channel Access security before writing values.
  • pendIOtime=<seconds> — Time to wait for Channel Access operations.
  • infiniteLoop — Run indefinitely.
  • controlLog=<rootname> — Log input and output data to an SDDS file using the given root name.
• see also:
  • sddsfeedforward()
• author: Michael Borland, ANL/APS.