Experimental Physics and
Industrial Control System

"Allison, Stephanie" <[email protected]> · Wed, 12 Jun 2013 16:14:55 -0700

Hi Bruce,

Regarding the problem where a record is tagged LINK INVALID when it tries to write to a read-only PV (same being true with trying to read from a no-read-access PV), instead of a message, I think both dbAccess.c and dbCa.c could be smart enough to check for the specific bad access status and set the PV to WRITE_ACCESS INVALID (or READ_ACCESS INVALID) instead of the more generic LINK INVALID.

Thanks for reminding me that a LINK status on a record does not necessarily mean some INP or OUT link with MS has an abnormal severity.  Can also mean bad status from dbGet and dbPut and will show up even if the INP or OUT is NMS.

Stephanie Allison

> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf
> Of Bruce Hill
> Sent: Friday, June 07, 2013 8:12 PM
> To: Techtalk
> Subject: Adding error msgs to dbAccess.c
> 
> We recently had an issue where an IOC that had been
> working for over a year stopped working.   On investigation,
> we found that one of the PV's was in a LINK INVALID state.
> 
> We finally traced that to dbAccess.c, and from there to a
> gateway configuration issue in which a missing hostname
> made a PV read-only that the IOC needed to write to.
> 
> I've created a small patch for 3.14.12 dbAccess.c that adds calls
> to recGblRecordError where recGblSetSevr is being called
> to set LINK INVALID due to a CA put error, along with a
> couple of other places where SEVR is set w/o any error msg.
> This would have saved us long hours of debugging if it
> had been in place earlier, so I thought it might be worth
> adding to base.
> 
> Thanks,
> - Bruce
> 
> --
> Bruce Hill
> Member Technical Staff
> SLAC National Accelerator Lab
> 2575 Sand Hill Road M/S 10
> Menlo Park, CA  94025

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System