回复: How to capture messages generated by PyEpics?

["Li, Ji via Tech-talk" <tech-talk@aps.anl.gov>]

Thanks Mark. I expect Wireshark to be install & play. The one I used is an old installation on an old server. Will find another one and try it out.

Best,

-Ji Li

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发件人: Mark Rivers <rivers@cars.uchicago.edu>
发送时间: 2021年2月18日 20:11
收件人: Li, Ji <liji@bnl.gov>
抄送: tech-talk@aps.anl.gov <tech-talk@aps.anl.gov>
主题: RE: How to capture messages generated by PyEpics?

 

Ø   When I get/set from PyEpics (tried both PV module and CA module), the program was able to successfully get the up-to-date value of the PV and set new value to it,

Ø  > but no messages showed up. Doesn't PyEpics communicate using CA protocol messages? Are there specific filter/configuration to be done in Wireshark to show these messages?

 

There is no difference in the CA network messages using caget and PyEpics.    They both use the same libca.so library from EPICS base.

 

You must have something configured wrong in Wireshark or something.

 

Mark

 

 

From: Tech-talk <tech-talk-bounces@aps.anl.gov> On Behalf Of Li, Ji via Tech-talk
Sent: Thursday, February 18, 2021 4:52 PM
To: tech-talk@aps.anl.gov
Subject: How to capture messages generated by PyEpics?

 

Hi,

 

I'm trying to capture CA messages targeting a specific PV on the IOC server with Wireshark (v1.12.1) and Michael Davidsaver's cashark plugin (ca.pv or ip.addr as the filter). Wireshark was able to capture messages generated by caget/caput commands ran from bash. When I get/set from PyEpics (tried both PV module and CA module), the program was able to successfully get the up-to-date value of the PV and set new value to it, but no messages showed up. Doesn't PyEpics communicate using CA protocol messages? Are there specific filter/configuration to be done in Wireshark to show these messages? Thanks.

 

 

-Ji Li