Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Thu, 7 Mar 2013 13:07:43 -0600

Hi Mike,

On 2013-03-07 Westfall, Michael D wrote:
> Does anybody have any tips as how to communicate via a serial interface to
> a device that takes commands and gives responses in binary bytes rather
> than ASCII?  We are using EPICS R3.13.4, and it appears that streamDevice
> is not available, or would require some extensive hacking to get it to
> work. devAscii is available, but since it relies heavily on string
> scanning functions, it will likely choke on any data that contain null
> bytes.

For 3.13.x we mostly used a C++-based module called MPF (Message Passing 
Facility) for handling serial devices, which had its own UART drivers (I think 
it could talk to a local serial port too, but I'm not 100% sure of that).  It 
was capable of handling binary messages, and could also use serial ports that 
were connected to remote (slave) machines.  However it might take a bit of 
learning to adopt that.

I do have one driver and device support that directly opens a local serial 
port on the vxWorks CPU  board and does binary I/O through it, although it may 
be more complicated than you'd like — it talks the Metasys protocol to Allen 
Bradley PLCs.  Whether the code's author (Bob Dalesio) can remember anything 
about though I have no idea, but I can send you a copy if you'd like it.

- Andrew
-- 
There is no such thing as a free lunch.  When invited for lunch,
it is best to check if you are there to eat, or to be eaten.
-- Clive Robinson

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System