Experimental Physics and
Industrial Control System

Hej Alex,
I need to correct myself.

A prototype which should have the RBV/DRBV field working is here:

<https://github.com/EuropeanSpallationSource/motor/commit/ed71166ba2c5a83b23e8528ab7196feefad25a5f>

Note that RRBV is wrapping around.

If you have a chance to test it, please let us know the results.

/Torsten



On 23/01/18 06:31, Torsten Bögershausen wrote:

Thanks for the report.

There is even an older discussion here:
https://github.com/epics-modules/motor/issues/8


And the situation can be improved:

<https://github.com/EPICS-motor-wg/axis/commit/7a125b9c90298a111d20555e6e3794ae9e16fb21>

I am working on a "backport" to the motor module,
this will take some days.
/Torsten


On 23/01/18 00:02, Mark Rivers wrote:

Hi Alex,

The problem is that the RRBV field in the motor record is a 32-bit integer:

This is from motorRecord.dbd:

         field(RRBV,DBF_LONG) {

                 prompt("Raw Readback Value")

                 special(SPC_NOMOD)

         }

The motor driver reads back the theoretical and encoder positions as doubles, but then they is converted to 32-bit integers in devMotorAsyn.c to be compatible with the fields in the record.

     if ( pPvt->needUpdate )

     {

         epicsInt32 rawvalue;

         rawvalue = (epicsInt32)floor(pPvt->status.position + 0.5);

         if (pmr->rmp != rawvalue)

         {

             pmr->rmp = rawvalue;

             db_post_events(pmr, &pmr->rmp, DBE_VAL_LOG);

         }

         rawvalue = (epicsInt32)floor(pPvt->status.encoderPosition + 0.5);

         if (pmr->rep != rawvalue)

         {

             pmr->rep = rawvalue;

             db_post_events(pmr, &pmr->rep, DBE_VAL_LOG);

         }

Mark

*From:* [email protected] [mailto:[email protected]] *On Behalf Of *Sobhani, Bayan

*Sent:* Monday, January 22, 2018 4:20 PM
*To:* [email protected]
*Subject:* How to work with motor record position counts larger than 2147483648?

I am working on adapting the SmarAct MCS motor record driver for the MCS2, which seems to record its position in picometers unlike the MCS’s nanometers.

I have the following code in my polling function:

Int64_t val = getp(0); //Gets position of channel 0 positioner

printf(“%f\n”,(double) val); //prints -6000093133.000000

setDoubleParam(c_p_->motorEncoderPosition_,(double)val);

setDoubleParam(c_p_->motorPosition_,(double)val);

…

callParamCallbacks();

return asynSuccess;

But when I look at the motor record, the RRBV is shown as -2147483648. I looked at asynMotorController.cpp and saw the line:

createParam(motorEncoderPositionString,        asynParamFloat64, &motorEncoderPosition_);

Shouldn’t this mean I can write 64-bit floating point values to motorEncoderPosition_ (i.e. larger than 2147483648)? How should I go about working with position counts larger than 2147483648?

Alex

References:

How to work with motor record position counts larger than 2147483648? Sobhani, Bayan

RE: How to work with motor record position counts larger than 2147483648? Mark Rivers

Re: How to work with motor record position counts larger than 2147483648? Torsten Bögershausen

Navigate by Date:

Prev: Re: PV Scan - Set values Anton Derbenev

Next: Re: PV Scan - Set values Ralph Lange

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: Re: How to work with motor record position counts larger than 2147483648? Torsten Bögershausen

Next: PV Scan - Set values Pilar Gil Jaldo

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