Yes.

UPDATE/CORRECTION:

It is possible that the Kepware server uses the tag update rates configured within it only for non-OPC clients, and that it uses the rates specified by OPC clients when the tags are addressed through OPC. How this works is really something you need to figure out with the server vendor, Kepware in this case.

Best regards

You start with the requirements of the application, and figure out the rate needed so that you receive the data as often as you need. This depends totally on the application, and you need to determine it yourself.

Some OPC servers will then take the update rate form the OPC client(s), and use it as the communication rate with the device. With such servers no further settings are needed, you just define the above determined rate as the update rate inside OPC.

Other servers (Kepware probably) scan the device independently from the update rates of any OPC clients. In such case, you should set the scan rate in the server to be at least as fast as what is required by the application, and then you typically set the OPC update rate to be twice as fast.