Experimental Physics and
Industrial Control System

"Chen, Xihui" <[email protected]> · Mon, 25 Jun 2012 11:17:12 -0400

Thanks for all the quick replies! Looks like this is a common issue and Jeff just have created a bug entry for it.

Regards,
Xihui 

________________________________________
From: Hill, Jeff [[email protected]]
Sent: Monday, June 25, 2012 11:11 AM
To: Chen, Xihui
Subject: RE: Large waveform PV through CA Gateway

I created bug entry 1017549. Note that Peng Sheng (of SLAC) is also
looking into this issue.

Jeff
________________________________________
From: Bertrand Alain Gregor [[email protected]]
Sent: Monday, June 25, 2012 11:07 AM
To: Chen, Xihui; [email protected]
Subject: RE: Large waveform PV through CA Gateway

Hi Xihui,

We have the exact same kind of issues with the current EPICS Gateway,
basically my understanding of the problem is that the gateway must wait
till all the IP packet for a given EPICS message came in, before being
able to re-construct the value in the "Server" part of the gateway and
only then send the event to the clients that a new value is there. This
introduce of course some latency.

Due to this issue and others, we are currently developing a gateway
implementation which works with a different approach and the initial
tests are promising.

Sincerely,

Alain Bertrand

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Chen, Xihui
Sent: Monday, June 25, 2012 16:50
To: [email protected]
Subject: Large waveform PV through CA Gateway

Hi,

I have a performance issue with transferring large image PV(2048*2048 at
1hz) through CA gateway. Without CA gateway, the client are able to
update at 1hz, but with ca gateway, it can only get updates every 10
second. The CPU usage on IOC, gateway and client are all very low. I
want to know if anyone has similar experience?

Thanks,
Xihui

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System