EPICS Home EPICS Controls Argonne National Laboratory

Experimental Physics and
Industrial Control System

Format page
for printing


Search Tech-talk
1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  <2023>  2024  Index 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  <2023>  2024 
<== Date ==> <== Thread ==>
Subject: Re: Question about asynMotor record, limits
From: Mark Rivers via Tech-talk <tech-talk at aps.anl.gov>
To: "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>, Borys Lysyansky <bor.lys at gmail.com>
Date: Fri, 21 Apr 2023 13:17:11 +0000
Hi Boris,

The problem is that the software limit checking is done in the EPICS motor record, not in the driver.  The motor record does send those limits to the driver, because in some cases the controller can also act on them.  But writing those values to the controller as you are doing does not set them in the motor record.  Your program should set the limits in the record, not in the driver.

Mark

From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Borys Lysyansky via Tech-talk <tech-talk at aps.anl.gov>
Sent: Friday, April 21, 2023 5:33 AM
To: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: Question about asynMotor record, limits
 
I have the following problem:

I have my asynMotor record with the following lines in
motor.substitutions:

{P,     N,   M,        DTYP,        PORT,             ADDR,  DESC,          EGU,   DIR,  VELO,  VBAS,  ACCL, BDST,  BVEL, BACC,  MRES,  PREC,   DHLM, DLLM, INIT}
{PREFIX:,  1,  "WL",         "asynMotor",  MyController,  0,  "motor $(N)",  nm,    Pos,  .0,   .0,    .0,    0,     1,    .2,    1e-6,     6,       17,     2,  "0"}

During the program run I would like to change the motor limits, which are now 2..17 with
the following code:

auto status1 = m_pAxes[0]->setDoubleParam(motorLowLimit_, newLowValue * 1e6);
auto status2 = m_pAxes[0]->setDoubleParam(motorHighLimit_, newHighValue * 1e6);

Both obtained status are asynSuccess. I have also checked the result by
calling

double lowLimit = 0, highLimit= 0;
getDoubleParam (0, motorLowLimit_,     &lowLimit);
getDoubleParam (0, motorHighLimit_, &highLimit);

It was also correct. However, I would expect that the new low/high limits
should have impact on commands
caput PREFIX:WL.VAL someValue

However, the program behavior here is somehow strange.
Could you, please, explain me it.

With best wishes,
Boris

References:
Question about asynMotor record, limits Borys Lysyansky via Tech-talk
Navigate by Date:
Prev: RE: Search all PV available CAOUEN Loic via Tech-talk
Next: mbbo with 32 choices Le, An via Tech-talk
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  <2023>  2024 
Navigate by Thread:
Prev: Question about asynMotor record, limits Borys Lysyansky via Tech-talk
Next: mbbo with 32 choices Le, An via Tech-talk
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  <2023>  2024 
ANJ, 21 Apr 2023 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·