Experimental Physics and
Industrial Control System

"Jeff Hill" <[email protected]> · Thu, 16 Jan 2003 08:57:22 -0700

> ....
> Thu Jan 16 21:47:10 CST 2003
> medmCAExceptionHandlerCb: Channel Access Exception:
>   Channel Name: Unavailable
>   Native Type: Unavailable
>   Native Count: 0
>   Access: Unavailable
>   IOC: Unavailable
>   Message: Virtual circuit disconnect
>   Context: 166.111.32.240:5064
>   Requested Type: TYPENOTCONN
>   Requested Count: 0
>   Source File: ../cac.cpp
>   Line number: 1532
>  ...
> -------------------------
> "166.111.32.240" is the ip address of the ioc.
>  What's the reason?any suggestions are appreciated. Thanks in
> advance.
> 

You might see this message in ordinary situations where the medm program
has lost communication with the IOC such as when the IOC powers down,
reboots, or its network cable is removed. This message might also occur
if there are software problems but it is difficult to speculate further
with this information. 

What version of EPICS are you running?

Here are some steps you can follow to find the cause of the problem.

1) Use the ping command from the medm workstation to verify that there
is network connectivity to your IOC.
2) Verify that there is not a CPU saturation problem on your RTEMS IOC
where 100% of the CPU is consumed.
3) Did the medm screen only disconnect briefly and then reconnect on its
own? Temporary disconnect problems existed in one of the early beta
releases of R3.14.
4) If not, does another program such as caEventRate connect to the IOC
in this situation?

Jeff

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System