Re: Delta Tau motor control problem

[Mark Davis <davism50@msu.edu>]

Hi Giles,

It took a while to get through the differences between the version I was 
using and this latest one, but I eventually got it running using the 
version you released yesterday.  Unfortunately, it hasn't made any 
difference.
Is there an easy way to test this functionality without going through 
the motor record so I can at least determine if the problem is in the 
driver or the motor record?
Does anybody know if there anything in the motor record that could cause 
this if the fields in the motor record that describe various aspects of 
the motor (e.g. velocity, acceleration, etc) are not properly configured?
Mark


Mark Davis NSCL/FRIB Control Systems Software Engineer davism50@msu.edu
On 8/1/2018 12:04 PM, giles.knap@diamond.ac.uk wrote:
> Hi Mark,
>
>
> See latest pmac at https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_dls-2Dcontrols_pmac_releases_tag_2-2D1&d=DwIFAw&c=nE__W8dFE-shTxStwXtp0A&r=D7ZiziuMQuq40HlGYOZPBg&m=hXNy61CAHm2fE0dEnE_T6w8Mom1Re8RSl3DCYELh4zE&s=nQGySqmgeIasdlsqnzhNQCIgICRA-EbDPaFv3g9Gkvs&e=
>
>
> I agree with Mark R that this is related to an interaction between driver and NTM but I don't think a well behaved driver should ever exhibit what you describe.
>
> ________________________________
> From: tech-talk-bounces@aps.anl.gov <tech-talk-bounces@aps.anl.gov> on behalf of Mark Rivers <rivers@cars.uchicago.edu>
> Sent: 01 August 2018 15:21:19
> To: tech-talk@aps.anl.gov; Mark Davis
> Subject: Re: Delta Tau motor control problem
>
> Hi Mark,
>
>
> The motor record contains an NTM field that controls the behavior when a new target value is entered and the motor is still moving.  What value does NTM have for your record?
>
> Mark
>
>
> ________________________________
> From: tech-talk-bounces@aps.anl.gov <tech-talk-bounces@aps.anl.gov> on behalf of Mark Davis <davism50@msu.edu>
> Sent: Wednesday, August 1, 2018 8:35 AM
> To: tech-talk@aps.anl.gov
> Subject: Delta Tau motor control problem
>
> HI all,
>
> I have run in to another problem with my attempts to control a stepper
> motor using a Delta Tau controller.
>
> Current configuration:
>
>      Motor Controller:  Delta Tau Power Brick LV-IMS
>      EPICS version:  3.14.12.2
>      Asyn module:  4.32
>      powerPMAC driver:  The 2014-09-25 version at
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.observatorysciences.co.uk_deltatau-5Fdownloads.php&d=DwIFAw&c=nE__W8dFE-shTxStwXtp0A&r=D7ZiziuMQuq40HlGYOZPBg&m=hXNy61CAHm2fE0dEnE_T6w8Mom1Re8RSl3DCYELh4zE&s=-YPCsQc3KmJAS2-hRXAfTk3oJfzx4jZLMLQTKgz_GEw&e=
>      IOC config:
>
>         #===== for Power Brick LV-IMS controllers =====
>         drvAsynPowerPMACPortConfigure("SSH1", "192.168.137.234", "root",
> "deltatau", "0", "0", "0")
>
>         # 'Ctlr port name', 'SSH port name'. 'port address'. '#axes'
> 'Moving poll interval (ms)', 'Idle poll interval (ms)'
>         powerPmacCreateController("PBRICK1", "SSH1", "0", "32", "25", "100")
>
>         # open-loop axes (they don't use the encoder readback)
>         pmacCreateAxis("PBRICK1", "3")
>
>         asynSetTraceMask("PBRICK1", 0, 0)
>         asynSetTraceMask("SSH1", -1, 0)
>         asynSetTraceIOMask("SSH1", -1, 0)
>
>         # includes a motor record...
>         dbLoadTemplate("db/powerPMAC.substitutions")
>
>
> Using this configuration, I can control the motor via the motor record
> just fine, as long as I wait until the motor reaches the new position
> after each new setpoint.
>
> However, if I change the setpoint while the motor is still moving, it
> will stop before getting to either the new or the previous setpoint, the
> done moving bit in the status value from the controller stays at 0, and
> new setpoints to the motor record are ignored.
>
> If I then give the controller a move command directly, this works fine:
> The motor moves to the new position and the done moving bit goes back to
> 1, at which point new setpoints applied to the motor record will work again.
>
> NOTE:  Changing the setpoint in a middle of the move using commands on
> the controller itself also works fine (e.g. it will happily reverse
> direction in the middle of a move to get to the latest setpoint).
>
>
> Given how long the motor record has been around, I assume that such a
> basic problem would have been resolved long ago.  And the controller is
> fine with changes to the setpoint during a move, so I would think that
> the problem must be in the driver.
>
> Has anyone run in to this sort of thing before?  Someone mentioned that
> the driver available from the Diamond Light Source incorporates the
> driver I am using (i.e. it should work for Geo Brick and Power Brick
> controllers?).  Does anyone now if this is a driver bug and whether or
> not it is fixed in the DLS version?
>
> Thanks.
>
> --
> Mark Davis
> NSCL/FRIB
> Control Systems Software Engineer
> davism50@msu.edu