Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Wed, 22 Apr 2015 12:15:36 +0000

Hi Peter,

Here is a result of a case-insensitive search for the string "odel" in the stdApp/src directory, where the epid record is located:

corvette:std/stdApp/src>grep -i odel *
epidRecord.dbd: field(ODEL,DBF_DOUBLE) {

So the field is defined in the record, but it not used in any of the code.  It probably should be implemented, as you suggest, but is not currently.

Mark

________________________________
From: [email protected] [[email protected]] on behalf of Peter Linardakis [[email protected]]
Sent: Wednesday, April 22, 2015 1:08 AM
To: [email protected]
Subject: Misunderstanding of epid record ODEL field?

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: [email protected]<mailto:[email protected]>
p: +61 2 6125 2862
w: http://physics.anu.edu.au/nuclear/

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System