Experimental Physics and
Industrial Control System

[email protected] (Bob Dalesio) · Fri, 7 Mar 97 08:10:01 MST

The caching of the strings for enums is the responsibility of the client.
Most clients fetch the type DBR_CONTROL_xxx at connection and then
only monitor the value/timestamp/status. This is true of CAU, DM, MEDM
at least. For a client to get the changes in the middle of operation
they would either have to 
1)monitor the entire structure and then the network traffic is increased 
	significantly
2) do gets - then you have a polled system with increased struture size

We are now considering as one of the extensions to channel access in 
version 4 - adding an event type that lets a regular monitor know that
the parameters that make up the largest composite type have changed -
then the client can reacquire the larger structure. Needless to say,
this is not yet done.

One way to prove that the string is working is to use the
dbpf - utility in the IOC.

Do you do this in an operational system - or as you are developing
an application?

	Bob

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System