Experimental Physics and
Industrial Control System

"Walters, M \(Malcolm\)" <[email protected]> · Thu, 15 Jun 2006 08:51:42 +0100

Allan,

This comes from the record reference manual
(
http://www.aps.anl.gov/epics/EpicsDocumentation/AppDevManuals/RecordRef/Recordref-5.html#HEADING5-308)

"A scan alarm is generated if a record is not successfully placed in the
desired scan list, or if it is found by the scan task to be locked in
ten successive attempts to process it. When a scan alarm occurs, the
alarm severity is always set to INVALID."

I guess if you look at the records they are all set as processing. It
may be that a message has been sent but no reply received and hence the
record is still waiting for a reply. If all records are using the same
port then the port may be locked by one and all others are simply
waiting for it to finish.

Is any communication to the device working? If possible it may be worth
logging the communications and seeing what the last message sent and the
reply was. Also is the remote device rebooted every day? It could be
that the device has a problem.

Malcolm

________________________________

	From: Al Honey [mailto:[email protected]] 
	Sent: 15 June 2006 03:15
	To: [email protected]
	Subject: STAT -> SCAN

	Aloha

	No not a CAT SCAN, although there are folks who think that may
be appropriate in my case.

	I have bumped into a recent problem that is subsequent to
upgrading to r3.13.10 on our PPC/VxWorks IOCs.

	I have 17 records that are scanned every 10 seconds. Those
records are connected to a remote device connected to a serial link.
About two weeks ago those records started to stop scanning an hour or so
after the IOC is rebooted (done daily) with no error being logged from
the drivers (simply no trace of why they stop scanning). When the
problem occurs the records' SEVR fields are set to INVALID and their
STAT fields are set to SCAN. 

	Can anyone enlighten me as to what at STAT field value of SCAN
implies?

	Note:  there is one other record in the 10 second scan task and
it is happily continuing to scan

	          the EPICS upgrade occurred 10 weeks ago

	Thanks

	            Allan

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System