Experimental Physics and
Industrial Control System

[email protected] (Jeff Hill) · Mon, 8 Mar 1999 10:02:14 -0700

On Monday, March 08, 1999 9:05 AM, Natalie Otey [SMTP:[email protected]] wrote:
> Hi,
> 
> I'm running two identical systems with identical databases on the same
> network. When attempting to run MEDM, it says that it sees the requested
> channel on two different IOCs. This is because the databases are identical.
> Do the channels names need to be unique??
> 

Yes, the channel names uniquely determine the process variable that is the
end point of communication so you must have only one channel with a particular
name in each EPICS system.

However, if you configure the port numbers that are used by the EPICS CA client and
the EPICS CA server then you can run several independent EPICS systems with
overlapping process variable (channel) name spaces on the same local area network 
(IP subnet). Details on EPICS CA configuration are on the WEB in the CA reference
manual.

It is also a common practice to embed process variable name prefix macros in the record 
names so that it is easy to retarget the all of the record names in a test database at load time.

Jeff

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System