Experimental Physics and
Industrial Control System

Benjamin Franksen <[email protected]> · Fri, 5 Aug 2016 17:23:07 +0200

I (re-)send this problem description by a colleague of mine with the
hope that perhaps someone has encountered similar problems and/or has an
idea how to further debug this.

"""
We have a PC with Windows 7 that has Labview and an EPICS base 3.14.12.2
installed. This PC connects to several channel access servers. The
servers that are Linux based, like a channel access gateway and a
softioc, make no problems. However, since last week, connections to a
vxWorks IOC are no longer possible.

"cainfo" for a PV on this IOC replies something like "connection reset
by host", although the correct host is mentioned. So it seems that the
name resolution request for the PV works but the connection to actually
transmit the data is interrupted or can't be established at all. Both
systems are within the same network collision domain.

A Linux channel access client in the same network has no problems with
it's connections to the same PVs, so it doesn't seem to be a server
related problem.

Now, if we change the IP address on the windows PC to another free
address in the network, channel access first works. Everything is fine
but only for 3 to 5 minutes. Then connections to the vxWorks IOC fail
again. Setting the IP address to a third variant has the same effect.
Everything works but only for a few minutes. Setting the IP address back
to the original one still doesn't work. Deactivating and  re-activating
the network interface doesn't help. After a while, maybe  15 to 30
minutes, an IP address that didn't work and wasn't used for that time,
can be used again, but still, only for 2 to 3 minutes.

Setting EPICS_CA_ADDR_LIST to the IP of the IOC and
EPICS_CA_AUTO_ADDR_LIST to "no" doesn't help. But channel access on the
windows PC is not completely broken. Requesting PVs from our linux
based channel access gateway or a linux soft-IOC always works.
"""

Cheers
Ben

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System