Updating sensor interval ua expert

[gefri]

Hi,
I am a beginner with using OPCUA.
I have sensors connected to the OPCUA(on a PLC) over io ports.
I use python "asyncua client" to get node values. (i don't think its pub sub, rather server client model)

For some nodes/sensors, the value updates every node query, for other nodes/sensors the value stays the same for a longer time period.
Is there a possibility to change the update speed or sampling speed for certain nodes, perhaps through ua expert?
Or could it be that the change in update frequency is due to the sensors and not the server?

Thanks in advance to any advice!

[Support Team]

Hi,

in the OPC UA Client/Server model there are 2 "rates" to consider, the "sampling" rate and the "publish" rate. The server can decide internally what "minimum scan rate" will be allowed for each individual node. Typically a temperatur sensor will be slower, and some gyro sensor will be faster.

The client can "request" the sampling and the publish rate, and the server will revise the rates that are possible. For effective communication your can "scan" quickly but "publish" slowly, which will make the server to queue high frequency sampled data, but send in large chunks (the collected queue). This is most efficient for the TCP/IP based transport.

With UaExpert you can test and investigate, to see how this works with your server.