Experimental Physics and
Industrial Control System

"Leonard J. Reder" <[email protected]> · Fri, 02 Jun 2000 09:31:42 -0700

Hi Brian,

Thanks very much for the reply.  I would like to look at the CPID
record and have read about it in the R3.13 Record Reference manual.
The problem is that in my EPICS distribution the record does not
seem to be included.

Could you  send me the cpidRecord.c and cpidRecord.dbd files and I
can hook them in and give it a try.

Regarads,

Len

Brian Bevins wrote:
> 
> "Leonard J. Reder" wrote:
> 
> Hi Len,
> 
> You might want to consider the CPID record we use here at Jefferson Lab.
> It uses the corrected equation for the integral term plus it adds other
> useful funtionality. It has limits on both the magnitude and rate of
> change of the output. It can write out the total output or the
> incremental change. It has special modes that allow the output to be
> overridden by program or operator control in an intelligent way (i.e.,
> smooth transitions between modes).
> 
> It is fully described (with a few typos) in the R3.13 Record Reference
> Manual. If you have trouble finding it or have other questions let me
> know.
> 
> Brian Bevins
> 
> 
> > Hello:
> >
> > I am utilizing the PID record within EPICS to perform closed loop
> > position control of some mirrors for our interferometer and some
> > questions came up.  The PID record's servo loop is now functioning
> > but not as expected.  Our application uses PZT like devices to position
> > a Newport Mirror mount and capacitive sensors to read back the position
> > into the CVL input of the PID record. The STPL input accepts the target
> > position for the mirror.  The PID record is feeding a AO record.
> > The AO is in incremental mode.
> >
> > For this system integral gain term is all we expect would be needed but
> > the servo does not respond at all until some proportional gain term is
> > added independent of the value of the integral term.  Basically the
> > integral term seems to be ignored are we missing something?
> >
> > One other problem I am seeing is that the medm/dm2k GUI does not seem
> > to be picking up the HOPR and LOPR field from the PID record.  Is this
> > a known bug.  How do I monitor on a GUI the ERR and DM fields?
> >
> > We are using EPICS Release 3.13.0.beta12.
> >
> > Any replies will be greatly appreciated.
> >
> > Len
> >
> > P.S. Thanks to Thomas Birke at Bessy and Kevin Tsubota at Keck for
> >      assistance in building the new dm2k application.
> >
> > --
> > ____________________________________________________
> > Leonard J. Reder
> > Jet Propulsion Laboratory
> > Interferometry Systems and Technology Section 383
> > Email: [email protected]
> > Phone (Voice): 818-354-3639
> > ____________________________________________________

-- 
____________________________________________________
Leonard J. Reder
Jet Propulsion Laboratory
Interferometry Systems and Technology Section 383
Email: [email protected]
Phone (Voice): 818-354-3639
____________________________________________________

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System