Misunderstanding of epid record ODEL field?

[Peter Linardakis <peter.linardakis@anu.edu.au>]

Hello techtalkers

 

I am trying to control a motor that drives a slow tuner based on phase and/or amplitude error signals.  It’s still just in testing but the basic control works.  However, The motor seems to attempt to move on every iteration of the epid loop, even if the magnitude of the epid.OVAL field is less than the epid.ODEL field.  Do I understand the intention of the ODEL field correctly?  I’d rather not have the motor try to move on every loop iteration.  The relevant records are below:

 

record(calc, "$(res):$(ta):tuning_error") {

  field(DESC, "Overall tuning error")

  field(INPA, "$(res):$(ta):phase_error")

  field(INPB, "$(res):$(ta):ampl_error")

  field(CALC, "B-3*A")

}

 

record(epid, "$(res):$(ta):tuner:control_pid") {

  field(DESC, "PID loop to control tuner postion")

  field(INP, "$(res):$(ta):tuning_error CPP")

  field(SCAN, ".1 second")

  field(SMSL, "supervisory")

  field(VAL, "0")

  field(OUTL, "$(res):$(ta):tuner:motor.RLV PP")

  field(FBON, "1")

  field(MDT, "5")

  field(KP, "-0.12")

  field(KI, "0")

  field(KD, "0")

  field(EGU, "mm")

  field(ODEL, "0.04")

  field(DRVL, "-1")

  field(DRVH, "1")

  field(DISV, "0")

  field(SDIS, "$(res):$(ta):tuner:mode CPP")

}

 

Thanks in advance

Peter

 

Dr Peter Linardakis

Accelerator Research & Development Engineer

Nuclear Physics | Research School of Physics and Engineering

Australian National University

e: peter.linardakis@anu.edu.au

p: +61 2 6125 2862

w: http://physics.anu.edu.au/nuclear/