Experimental Physics and
Industrial Control System

Mazanec Tomáš <[email protected]> · Thu, 16 Apr 2015 12:37:34 +0000

Hi Marek

I'm not sure if I understand your setup correctly, so...

you're using RS232 device attached to a computer where an IOC with streamDevice is running in order to acquire data from it. 
If the device is set to transmit data, it does that at 10Hz rate.
An EPICS record is configured with SCAN="I/O Intr", DTYP=stream.... and reads the data using streamDevice protocol command which has only "in" command defined.

If so, it should work smoothly.
Of course, it depends on data. What is the amount of data and what structure it has ?
And then it depends on serial line speed.

Which of the device modes (Polling, Interrupt) sends the data automatically and periodically at 10Hz ?
Does the interrupt mode means the data are sent in the same way as poll but non-periodically ?

I've checked S-LINK's product webpage. It mentions some "Fast rate data transfers to PC" at 10kHz rate. Is this the case ?

I'm interested, we have got one S-LINK in lab too. However its integration to EPICS may not happen at all.

Thanks,
Tomas Mazanec

________________________________________
Od: [email protected] [[email protected]] za uživatele bohmm [[email protected]]
Odesláno: 14. dubna 2015 12:07
Komu: Tech talk
Předmět: Gentec S-link power meter problem with ending I/O interrupt    measurement

Hello,
  I am an EPICS newbie and trying to implement statistics functions for
our energy meter. Our laser system is running at 10 Hz and the energy
meter has to catch every pulse energy/power value for the statistics to
be computed properly. So the energy meter is running with an external
trigger. I am communicating with the device via StreamDevice using
serial commands.

  The device supports two acquisition modes: Polling ("Free running") and
I/O interrupt (device is generating interrupts).

The problem is, once I get into I/O Interrupt mode @ 10 Hz, the device
is so busy receiving the data, that any other byte streams send to it
via StreamDevice do not get through. The consequences are that I am not
able to send the command to end the I/O Interrupt mode once I started it
and get back to Polling ("free running"), and also that the devices does
not receive its other statuses.

At really low repetition rates (@ 0.5 Hz) this problem does not occur,
the device has "time to answer".

Did anybody deal with a similar problem? Is it possible to solve without
writing a driver?

Best regards

Marek Böhm

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System