Re: Galil controller with incremental encoder question

[Mark via Tech-talk <tech-talk at aps.anl.gov>]

    Hi Mark,
    I hope you are doing well?  It's good news that the issue is
    solved.  Sounded like a tricky issue indeed.
    
    In case you're interested in trying the home routines provided, the
    control settings are located toward the bottom of the motor extras
    screen.  It's possible to configure the home settings so the current
    position, except on an active limit, is used as home.  To support
    the motor extra feature "wrong limit protection", the provided home
    routine will back off a limit during homing, assuming the home
    process completes successfully.  If the home process times out
    (unsuccessful), then the process could complete whilst a limit is
    still active.  Custom home routines can be delivered to the
    controller using GalilReplaceHomeCode iocShell function.  The
    GalilReplaceHomeCode function takes the target axis and a code file
    name as parameters.  GalilReplaceHomeCode will substitute the macro
    $(AXIS) found in the specified code file with the axis name
    specified.  The GalilReplaceHomeCode iocShell function is rarely
    used, but there are a few production cases.  The axis/motor record
    homed status can be checked by middleware before driving it.
    
    I highly recommend the Qt EPICS framework as a display technology
    for use with the Galil driver.  The Galil driver has both MEDM and
    Qt EPICS screens provided.
    The folks at the Australian Synchrotron have developed a fantastic
    GUI technology for use with EPICS.
    https://qtepics.github.io/
    The Qt EPICS framework integrates into Qt designer, providing a drag
    and drop GUI builder, so sites can make their own screens too.
    
    Kind regards,
    Mark Clift

On 22/03/2024 12:51 pm, Mark Rivers wrote:

Hi Mark,

 

I have solved the problem.  It is related to the problem in this tech-talk thread:

https://epics.anl.gov/tech-talk/2024/msg00121.php

 

My template file did not define ERES, only MRES.  Thus, encoder ratio was infinite during iocInit, which resulted in setEncoderPosition not being called when the motor position was set.  This problem is hard to spot because ERES is later set to MRES in iocInit, so it appears OK.

 

Based on my previous problem, devMotorAsyn.cpp has been fixed to avoid this issue.  When I updated my motor version to master with that fix the problem is gone.  I could have also fixed it by adding ERES to the template file.

 

Sorry for the bother.

 

Thanks,

Mark

 

From: Mark Rivers <rivers at cars.uchicago.edu>
Sent: Thursday, March 21, 2024 6:07 PM
To: tech-talk at aps.anl.gov; padmoz at tpg.com.au
Subject: Re: Galil controller with incremental encoder question

 

Hi Mark,

 

Thanks for the reply, sorry it's taken awhile to get back to this.

 

I am working on axis C on a Galil 4183 with the D3140 servo amplifier unit installed.  

 

I have attached a screen shot of the motorx_all screen (Galil.png).  I have also attached a screen shot of the galil_motor_extras.adl for this axis (Galil_extras.png).

 

The axis is configured as Servo with Reverse Quadrature encoder.  (The problem happens with Normal Quadrature as well).

 

In the motorx_all screen I have set Use Encoder=Yes (UEIP field).  I put the axis in Set mode and type 0 into the VAL field.  VAL, DVAL, and RVAL all set set to 0 as expected.  However, RRBV, RBV, and DRBV do not change, they are the same encoder readback as before I set the position.

 

• Ensure dual feedback mode is off with DFx=0. 

 

I have done that.

 

• I recommend checking if the value is written to the hardware correctly by using Galil commands DEx=?, DPx=? (where x is the motor in range A-H). 

 

DEC=? returns 0, but DPC=? returns -4000, so the encoder value was not written to the hardware.

 

Here are the PVs you asked about:

 

(base) [epics@corvette ~]$ caget 13BMC:Galil7:m73_MTRTYPE_CMD

13BMC:Galil7:m73_MTRTYPE_CMD   Servo

 

(base) [epics@corvette ~]$ caget 13BMC:Galil7:m73_MTRTYPE_STATUS

13BMC:Galil7:m73_MTRTYPE_STATUS Servo

 

(base) [epics@corvette ~]$ caget 13BMC:Galil7:m73_MENCTYPE_CMD

13BMC:Galil7:m73_MENCTYPE_CMD  Reverse Quadrature

 

(base) [epics@corvette ~]$ caget 13BMC:Galil7:m73_MENCTYPE_STATUS

13BMC:Galil7:m73_MENCTYPE_STATUS Reverse Quadrature

 

(base) [epics@corvette ~]$ caget 13BMC:Galil7:m73_AENCTYPE_CMD

13BMC:Galil7:m73_AENCTYPE_CMD  Normal Quadrature

 

(base) [epics@corvette ~]$ caget 13BMC:Galil7:m73_AENCTYPE_STATUS

13BMC:Galil7:m73_AENCTYPE_STATUS Normal Quadrature

 

(base) [epics@corvette ~]$ caget 13BMC:Galil7:m73.ERES

13BMC:Galil7:m73.ERES          0.0001

 

(base) [epics@corvette ~]$ caget 13BMC:Galil7:m73.MRES

13BMC:Galil7:m73.MRES          0.0001

 

Thanks,

Mark

 

---

From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Mark Clift via Tech-talk <tech-talk at aps.anl.gov>
Sent: Wednesday, March 13, 2024 9:49 PM
To: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: Re: Galil controller with incremental encoder question

 

Hi Mark,

On my test system, using a motor with incremental encoder, I can set the position and RRBV updates to the new value.  So I am unable to reproduce the error at this time.

 

Setting a new motor position involves setting the position on the controller and then reading the position back in the poll cycle.  I recommend checking if the value is written to the hardware correctly by using Galil commands DEx=?, DPx=? (where x is the motor in range A-H).  I'd need to know the motor type to determine which of the above 2 commands to use, so I recommend trying both of the above commands.  At the bottom of the DMC controller screen, is a console where folks can type Galil commands whilst the driver is running.  If the value is not written to hardware I recommend checking GalilAxis::setPosition and GalilAxis::setEncoderPosition methods to find where the write to hardware is failing.

 

Generally speaking with stepper motors, ERES and MRES are different values and both must be set if an encoder is used.  With servo motors ERES, and MRES are normally the same.

 

The GalilAxis::poller method reads the motor readback position from hardware, it's a good place to look if the driver isn't reading the value from the hardware correctly.

 

Ensure dual feedback mode is off with DFx=0.  If DFx=1 then the main and auxiliary encoder registers are swapped.

 

If no solution is found, could you please report the value of the following records on your system:

$(P)$(M)_MTRTYPE_CMD

$(P)$(M)_MTRTYPE_STATUS

$(P)$(M)_MENCTYPE_CMD

$(P)$(M)_MENCTYPE_STATUS

$(P)$(M)_AENCTYPE_CMD

$(P)$(M)_AENCTYPE_STATUS

$(P)$(M).ERES

$(P)$(M).MRES

And I will try again to reproduce the problem.

Kind regards,

Mark Clift

 

 

 

 

 

 

Virus-free.www.avg.com