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<== Date ==> <== Thread ==>
Subject: Re: "buffer over-write" problem with StringIn record
From: Ralph Lange <[email protected]>
To: Maurizio Montis <[email protected]>
Cc: EPICS Tech Talk <[email protected]>
Date: Thu, 10 Sep 2009 11:01:55 -0400
Hi Maurizio,

there's not much you can do inside the stringin record - it will post a value whenever it gets processed and the string changes.

The CA Archiver keeps a ring buffer for each channel, where values are stored until the buffer is flushed out to disk.
The "buffer overwrite" will occur usually on monitored channels, if values are coming in with a much higher rate than the archiver configuration declares. You have to adjust the archiver configuration:
  • Start a command line camonitor on the channel to see how fast the updates are.
  • Set the <period> for the channel to something that gets close to the real update rate.
  • If update rates are changing a lot: Increase the <buffer_reserve> for a higher safety margin.
Good luck!
Ralph


Maurizio Montis wrote: 
Hi,
i have an IOC connectied with an High Current Power Supply and i use
StringIn/StringOut records to comunicate with it. I also have an EPICS
Archiver that archives any PV in my Channel Access, but i have a
"buffer over-write" problem with the StringIn record. If i have Ai
records i know i have to set ADEL and MDEL fields, but i would like to
know if i can do the same with my StringIn and/or how i have to set my
record to solve this problem.
Thanks a lot!

Maurizio M.
References:
"buffer over-write" problem with StringIn record Maurizio Montis
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