Re: Delta Tau Power Brick LV-IMS driver

["giles.knap@diamond.ac.uk" <giles.knap@diamond.ac.uk>]

Hi Mark,


My reading of the code is that there are only two possible causes of the problem bit being set.

1) an amp fault

2) axis limits are disabled


If the cause is 2 then you should be seeing the message:-

*** WARNING *** Limits are disabled on controller %s, axis %d

The driver allows you to override the check for disabled limits by calling pmacDisableLimitsCheck() in the startup script.


We have recently released a model 3 driver that supports both geobrick and power pmac. It has better diagnostics than the original Observatory Sciences driver (upon which it's ppmac support is based) and should always print a reason for setting the problem bit.


If you do try out the new driver then please note that it will also set the problem bit if any coordinate sytsem feedrates are below the default threshold of 100%. You will need to set the threshold to 0 for a ppmac, see the PV $(P):FEEDRATE_LIMIT".


See https://github.com/dls-controls/pmac.<https://github.com/dls-controls/pmac>


Regards,

giles

________________________________
From: tech-talk-bounces@aps.anl.gov <tech-talk-bounces@aps.anl.gov> on behalf of Mark Davis <davism50@msu.edu>
Sent: 06 July 2018 16:13:01
To: tech-talk@aps.anl.gov
Subject: Delta Tau Power Brick LV-IMS driver

Working with some new equipment here and having some problems getting
things working correctly and hoping someone can give me some tips on
what to look for.

We have a couple of new Delta Tau Power Brick LV-IMS controllers that I
need to get working ASAP.

Here is where I am at the moment:
    - I have an EPICS 3.14.12.2 IOC running the following:
        - The powerPMAC driver from
http://www.observatorysciences.co.uk/deltatau_downloads.php,
        - The ssh2 library as described in the manual for the driver
        - Version 6-9 of the motor module
        - Version 4-23 of the asyn module
        - The records included in the example/test IOC config included
with the driver (which includes a motor record)
    - The latest PowerMAC IDE application from Delta Tau running on a
Windows 7 computer
    - A FESTO stepper motor (Model EMMS-ST-57-S-SEB-G2), which includes
a brake and an encoder
    - The appropriate power supply from Delta Tau to provide the power
for the controller and (through it) the motor
    - A very basic configuration/program running on the Delta Tau (one
which I was told is basically a copy of one of the examples provided by
Delta Tau) which includes definitions for 8 open-loop axes (where the
reported position is based on the # of steps) and 8 read-only virtual
axes that report the position based on the encoder counts.

Both the IOC and the IDE application can connect to the Delta Tau, and I
can open a command-line shell to it via SSH (the controller runs some
version of Linux)

If the IOC is not running, when I use the IDE application to jog the
motor it will move until it reaches the the specified position.

When the IOC is running, if I change the setpoint for the motor record,
the motor moves a bit in the correct direction but quickly stops.  This
is presumably because the PROBLEM bit in the motor record's MSTA field
is always set so the motor record is in the major STATE alarm state,
causing the record logic to stop the motor movement.

The brief description of the PROBLEM bit simply says "driver stopped
polling, or hardware problem".  But fields in the motor record are
frequently updating, showing any changes in the position of the motor,
so I wouldn't think it would be a polling problem.  And the fact that
everything appears to work fine when using the IDE application would
seem to imply that there are no hardware problems.

I will be digging through the code trying to trace this back to some
identifiable cause, but if anyone has any experience with this
controller and has some tips on what I might check or should be looking
for, that would be much appreciated.

Mark Davis
NSCL/FRIB


    - The ssh2 library


I have this driver installed on a Linux box running EPICS 3.14.12.2 and
(as explained in the doco for this driver) installed the libssh2 library
it needs to open an SSH connection to the controller.

I know almost nothing about the controller itself, but was provided with
a very basic "project" with some code that I was told is mostly a copy
of some example from Delta Tau.

I have

-- 
This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail.
Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd. 
Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message.
Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom