Thanks Bob, I'm aware of being able to change the scan rate this way.
But longer scan rate is not really desirable. The typical task performed
by the device is only a couple of seconds, so long scan rate for status
updates would be close to useless.
David
---
Dr. David Michel
Address: 8 Viking Drive, Didcot, OX11 9RD, Oxfordshire
Mobile: 0789 670 98 01 - Home: 0123 581 46 93
On 3 September 2014 14:26, Dalesio, Leo <[email protected]
<mailto:[email protected]>> wrote:
If you need a longer scan rate - you can modify menu.dbd. I think
that the instructions in the Application Developer's Guide covers this.
Bob
________________________________________
From: [email protected]
<mailto:[email protected]>
[[email protected]
<mailto:[email protected]>] on behalf of Mark Rivers
[[email protected] <mailto:[email protected]>]
Sent: Wednesday, September 03, 2014 8:08 AM
To: David Michel; EPICS mailing list
Subject: RE: Processing a record a in loop
What is the maximum/typical time between when you send a query and
receive a response?
You should be able to set the timeout to a value just longer than
the maximum and then you can process the record with any fixed rate
(1 seconds, 10 seconds, etc.). The record will be busy (PACT=1) if
the next scan interval happens before the reply from the previous
one. So it will not keep sending query messages, it will wait for a
reply before proceeding.
What does your protocol file look like? Is it a single query per
response, etc.?
Mark
________________________________
From: [email protected]
<mailto:[email protected]>
[[email protected]
<mailto:[email protected]>] on behalf of David Michel
[[email protected] <mailto:[email protected]>]
Sent: Wednesday, September 03, 2014 6:02 AM
To: EPICS mailing list
Subject: Processing a record a in loop
Hi All,
I'm using StreamDevice to talk to a custom device that doesn't
support I/O interrupt so one has to keep sending commands to it to
get status information.
Problem is that after a while (~ couple of hours), the device's
buffer fills up and doesn't reply anymore. Increasing the
ReplyTimeOut improves things slightly, but the problem still
eventually occurs.
One potential solution would be to send the next command only once
the previous one has returned in a loop (instead of using a set
frequency).
Making the record FWD link to itself doesn't seem to do it... I
started something using purely database trickery with a FANOUT
record set with a fixed SCAN field and disabling it depending on
whether the streamdevice record has finished processing or not...
but it's getting messy
Is there an elegant way of doing this?
David
