Re: How to support a new stepper motor controller?

[Maren Purves <m.purves@eaobservatory.org>]

Coming from the EPICS of 20 years ago, I still would do the same

only with more modern drivers/device support (we're still using

drvAscii, drvSerial, tnetIo from when we implemented ours):

it's just a device on a serial line, it an be controlled with analogout-s

or stringout-s, and similar for input, strings being put together or
split apart in gensub-s/asub-s.

Being faced with a similar problem, what is/are today's serial line

on terminal server/CMS drivers of choice?

Maren

On Mon, Feb 6, 2017 at 11:53 PM, Ralph Lange <ralph.lange@gmx.de> 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