Experimental Physics and
Industrial Control System

Eric Norum <[email protected]> · Fri, 31 Oct 2008 13:54:11 -0500

I'm not that familiar with the internals of Streamdevice. Dirk will
be able to confirm this, but I'm pretty sure that the write/read
operations are done with the port locked.
On Oct 31, 2008, at 1:45 PM, Szalata, Zenon M. wrote:
Thanks Eric,

I think I can combine these two IOC's into one. Once that is done,
do I need to do anything special to coordinate orderly access to the
two instruments or does asyn handle it for me?
Thanks again,
Zen
-----Original Message-----
From: Eric Norum [mailto:[email protected]]
Sent: Friday, October 31, 2008 10:03 AM
To: Szalata, Zenon M.
Cc: EPICS Techtalk
Subject: Re: GPIB - asyn - streamdevice
Would it be possible to run both instruments from the same soft IOC?

I don't think that it would be easy to try and mutex the requests
from separate clients of the GPIB/LAN adapter.
On Oct 31, 2008, at 11:05 AM, Szalata, Zenon M. wrote:
I have two GPIB instruments attached to ICS 8065 Ethernet - GPIB
Controller (according to the manual this device is a replacement for
the Agilent E2050 and E5810).  I have written two soft IOC's to
control and monitor two instruments (one is Agilent 33220A Waveform
Generator, the other is Boonton 4500B RF Peak Power Analyzer).  Both
IOC programs use epics R3-14-9, asyn R4-9, and streamdevice R2-3.
The 33220A IOC has a records with SCAN="1 second", which reads the
status byte.  The 4500B IOC has a waveform record with SCAN="5
second", which is used to read waveform data, a stream of ASCII coded
floating point values.  The waveform consists of 500 data points.
This stream of data is converted to floating point data in a genSub
record.
The 4500B IOC program performs flawlessly when it is the only one
running.  When the 33220A IOC program is also running, the waveform
data read by the 4500B IOC gets corrupted from time to time.  I
interpret what is happening as follows: while the waveform data is
being read, the other IOC program requests a status byte and somehow
these two concurrent operations interfere with each other.  How can I
solve this?  Is it possible to make reading the waveform an atomic
operation (i.e. uninterruptable)?
I am using the following streamdevice protocol for reading the
waveform:
rTDCh12{ InTerminator="";  out "TRAC:SOUR CH\$1;:TRAC\$1:INDEX
1;:TRAC\$1:AVER:DATA?"; in "%10000c";}
Any suggestions will be greatly appreciated.
Zen

--
Eric Norum <[email protected]>
Advanced Photon Source
Argonne National Laboratory
(630) 252-4793

--
Eric Norum <[email protected]>
Advanced Photon Source
Argonne National Laboratory
(630) 252-4793

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System