| This is most likely a DCOM security
issue. DCOM security must be opened up on both the server and
the client PC. On startup the OPC client (Citect) will
request data from the OPC server and if the OPC server PC has
security set which allows access, the server will respond with the
data.
Since the OPC client PC initiated the read request the client is
expecting a response and reads the data from the server but after
the initial startup it is the OPC server which notifies the client
of any change in data. Keeping that in mind, if the OPC
client machine is not configured to allow access from the OPC
server then it will never allow any change in data notifications
through and will never update the tag values.
You can modify DCOM security in the dcomcnfg.exe program found
in the WinNT\System32 directory.
|
