Experimental Physics and
Industrial Control System

"[email protected]" <[email protected]> · Mon, 9 Jul 2018 08:00:28 +0000

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: [email protected] <[email protected]> on behalf of Mark Davis <[email protected]>
Sent: 06 July 2018 16:13:01
To: [email protected]
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

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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System