EPICS Home EPICS Controls Argonne National Laboratory

Experimental Physics and
Industrial Control System

Format page
for printing


Search Tech-talk
1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024  Index 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024 
<== Date ==> <== Thread ==>
Subject: Re: Read and Write errors with VME-EVR-300
From: Andrew Johnson via Tech-talk <tech-talk at aps.anl.gov>
To: Michael Davidsaver <mdavidsaver at gmail.com>, "Hong, Ran" <rhong at anl.gov>
Cc: "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>
Date: Wed, 5 Oct 2022 11:45:51 -0500
On 10/5/22 10:56 AM, Michael Davidsaver via Tech-talk wrote:
Talking of seeing a change when a separate card is
acting as VME arbiter make me wonder if a similar
sort of issue has arisen.

When we got our first MVME board that used a Tempe (TSI-148) chip we found that unlike the older VMEchip2 and Universe-2 chips the Tempe would not release some of the strobe lines (probably DS*, AS* and/or IACK* but I forget exactly which) at the end of a bus cycle until it needed to run the next bus cycle or to release ownership of the bus. The older VME chips released those/that strobe immediately, whether they had another cycle to run or not. There was no timing requirement from the VMEbus spec that a bus master should do that, but at least one of our older VME I/O boards had problems with that — it might have been that it didn't actually cancel its internal "interrupt pending" state until IACK* got released. IIRC using another board as the system controller made the Tempe release the strobe and its ownership of the bus at the end of the cycle, thus resolving the issue.

Not sure if this Tempe behavior could help explain the problem, probably not though...

- Andrew
-- 
Complexity comes for free, Simplicity you have to work for.
References:
Read and Write errors with VME-EVR-300 Hong, Ran via Tech-talk
Re: Read and Write errors with VME-EVR-300 Michael Davidsaver via Tech-talk
Navigate by Date:
Prev: Re: Read and Write errors with VME-EVR-300 Michael Davidsaver via Tech-talk
Next: Re: EPICS mrfioc2 and new mtca card EVRTM-300 Michael Davidsaver via Tech-talk
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024 
Navigate by Thread:
Prev: Re: Read and Write errors with VME-EVR-300 Michael Davidsaver via Tech-talk
Next: How to read ENUM type PV using PvaClientChannel calss? Jörn Dreyer via Tech-talk
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024 
ANJ, 05 Oct 2022 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·