EPICS RE: [EXTERNAL] Bus errors accessing VME with base 7.0.6.1 and latest synApps modules

Experimental Physics and Industrial Control System

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 ==>

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: [EXTERNAL] Bus errors accessing VME with base 7.0.6.1 and latest synApps modules

From:

Mark Rivers via Tech-talk <tech-talk at aps.anl.gov>

To:

"Hartman, Steven" <hartmansm at ornl.gov>

Cc:

"tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>

Date:

Thu, 9 Jun 2022 21:06:04 +0000

The A16 addresses are always at the in the “mailbox register” address range of the IP330 Industry Pack module in the crate. They only happen when the IP330 module is being used. Its interrupt service routine reads the contents of those mailbox registers. So those are real recently used addresses. Those addresses are readable, but not writeable. It seems that the bus error is arising because that address is being written.

Mark

From: Hartman, Steven <hartmansm at ornl.gov>
Sent: Thursday, June 9, 2022 3:58 PM
To: Mark Rivers <rivers at cars.uchicago.edu>
Cc: tech-talk at aps.anl.gov
Subject: Re: [EXTERNAL] Bus errors accessing VME with base 7.0.6.1 and latest synApps modules

Looking for an example with A16 access, I only found one, embedded in the first email of the thread . . .

[Wed May 18 20:23:06 2022] VME Bus Error accessing A16: 0x300e
. . .
[Wed May 18 20:23:06 2022] 0x55d8aa0 (CAS-event): The task has been terminated because it triggered an exception that raised the signal 10.

. . .

ioc13ida> tt 0x55d8aa0
. . .
fr0 = -1

No obvious relation between -1.0 and 0xfbff300e, though. For the A32 access errors, the FR0 value appears to always match the bad address.

--
Steven Hartman
hartmansm at ornl.gov

On Jun 9, 2022, at 1:56 PM, Hartman, Steven via Tech-talk <tech-talk at aps.anl.gov> wrote:

On Jun 9, 2022, at 12:05 PM, Mark Rivers via Tech-talk <tech-talk at aps.anl.gov> wrote:

I am now convinced that the A32 addresses which generate VME bus errs are in fact the double values that are written to the ao records.

And this number shows up in the floating point register for the terminated task as FR0 . . .

VME Bus Error accessing A32: 0xbfe26ed0
...
fr0 = -0.576028

0xbfe26ed000000000 = -5.7602691650390620e-1

VME Bus Error accessing A32: 0xbffffffc
...
fr0 = -2

0xbffffffc00000000 = -1.9999961853027344

Still the big question as to where this is being treated as an address.

--
Steven Hartman
hartmansm at ornl.gov