Experimental Physics and
Industrial Control System

Kevin Peterson <[email protected]> · Tue, 7 Feb 2017 11:04:19 -0600

In general, the recommendation to write a model 3 driver is a good one.
Under some circumstances, however, that is far from the easiest option.

If the controller doesn't have a status command that allows queries of
the moving state, it can be awkward and inefficient to make the model 3
driver work well with the motor record, which expects the driver to
reliably set the done bit of the MSTA field.

If the goal is EPICS support and the motor record is not required, I
have found that StreamDevice support
(http://epics.web.psi.ch/software/streamdevice/) is a much better fit
and significantly easier to write.

Kevin

On 2/7/17 3:53 AM, Ralph Lange wrote:
> Dear motion specialists,
> 
> I am writing on behalf of Paramveer Jain (in CC) who has contacted me
> with this issue, but as I have never done motion control integration
> with EPICS, I'd rather throw this ball up than send him into the wrong
> direction.
> 
> He is being tasked with developing EPICS support for a locally developed
> motor controller.
> 
> The hardware setup can be summarized as:
> 
>   * Moxa embedded TCP-to-serial converter (NE4110S)
>   * Serial connection (RS-232)
>   * Homemade motor controller (based on an AT89C52)
>   * Ark Motion AMS 3630 stepper motor driver.
> 
> The controller software talks ASCII in command/response fashion, e.g.:
> 
>   * Read position (rotary encoder)
>     Command: STX U <CR>
>     Response: STX U pppppp <CR>
>     pppppp = six digit hex (divide by 640 to get millimeter)
>   * Go to position (rotary encoder)
>     Command: STX P1 sss pppppp <CR>
>     Response: \06 (ACK)
>     sss = three digit hex (speed in mm/s multiplied by 240)
>     pppppp = six digit hex (millimeter multiplied by 640)
>   * ...
> 
> What's the best/easiest way to do this? What are the caveats?
> Is there a tutorial he could follow?
> Is there existing support for another motor that he could start from?
> 
> Thanks a lot for your help!
> ~Ralph
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System