Re: GPIB - asyn - streamdevice

[Eric Norum <norume@aps.anl.gov>]

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:norume@aps.anl.gov]
> 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 <norume@aps.anl.gov>
> Advanced Photon Source
> Argonne National Laboratory
> (630) 252-4793

--
Eric Norum <norume@aps.anl.gov>
Advanced Photon Source
Argonne National Laboratory
(630) 252-4793