Experimental Physics and
Industrial Control System

"Konrad, Martin" <[email protected]> · Tue, 8 Oct 2013 05:14:06 +0000

Hi Christian,
 > thanks for all the nice suggestions how to solve my shell command 
problem.
> Of all presented solutions i like the "subroutine record" or the
> "StreamDevice" solution most.
> In both cases i have to implement a new iocsh function in C to do the
> system() call, as shown in the example from Emmanuel.
You do _not_ need any IOC shell functions to use the system() call from 
a subroutine record. system() is a C function, it doesn't care about the 
IOC shell. But keep in mind that record processing usually is intended 
to be very fast. Starting external processes that communicate with 
hardware definitely isn't. It might work for you right now but you might 
run into problems later. Of course you can spawn an own thread for that 
on IOC start. This thread then starts the external process when you send 
it a signal. A lot of code for such a simple thing. That's why I would 
prefer the streamdevice solution.

Martin

-- 
Martin Konrad
Control System Engineer
Facility for Rare Isotope Beams
Michigan State University
640 South Shaw Lane
East Lansing, MI 48824-1321, USA
Tel. 517-908-7253
Email: [email protected]

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System