Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Thu, 27 Sep 2007 10:48:57 -0500

Hi Heinrich,
Heinrich du Toit wrote:

I have 2 network cards in my PC - this is to connect directly to both
the campus and the control network here at iThemba LABS.
Now I have eth0 and eth1
If I start an IOC and then look for a PV then both interfaces seem to
return then I get error, although this is the same IOC?

Do you ever expect to have any IOCs on the campus network at all? If
not, the solution is to configure the CA client library to send CA
searches only to the control network. It is not possible with the
current code to tell the IOC server to only export its PVs to a
particular network on a machine with multiple interfaces, but as long as
the clients only search one network they won't see the problem (for the
purposes of the above explanation, the IOC is a client as well as a server).
To tell the client library to only search the control network, set the
following two environment variables

EPICS_CA_AUTO_ADDR_LIST=NO

EPICS_CA_ADDR_LIST=<broadcast address of control subnet>

The broadcast address is shown on the output from /sbin/ifconfig -a and
is probably 172.16.4.255 but it may have different numbers in the 3rd or
4th positions.
As long as those variables are set before you start the IOC and/or any
other clients you shouldn't see the duplicate PV warning.
- Andrew
--
When a distinguished but elderly scientist states that something is
possible, he is almost certainly right.  When he states that something
is impossible, he is very probably wrong.  -- Arthur C. Clarke

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System