A Question about Siemens Enhanced Driver

I have a client that is currently using the Siemens’ builtin OPC UA Server on an S7-1500 PLC. They’ve reached a point where the OPC-UA server cannot keep up with their requests for updated data and were getting a lot of GoodOverload errors.

Working with them I was able to get them to back off their requests to a point where if there are still Overload errors, they’re infrequent enough for me not to able to observe them happening directly.

They’d like to address this issue by switching to the Siemens Enhanced driver, but I want to make sure it actually works the way I think it does prior to encouraging them to invest in it.

The Enhanced driver allows for symbolic name browsing without the need for using the OPC server, right?

Once I enable the Enhanced driver and configure the tags to look at the correct path, I should be able to completely disable the OPC UA server in the Siemens PLC, right?

For context, if I were to include what they are historizing they are attempting to poll less than 30K tags, all on the local network, with a latency of no more than 3ms. They want to be polling most tags at a rate of 1 second, with the rest at a 3 second poll rate, but right now they can only have a select few tags at 1 second, with most tags at 5 and even 10 seconds poll rates to prevent the good overloads.

Yes, this part is right.

Whether you can actually achieve 30k tags at 1s is another matter and you'll have to try it and see... the symbolic access performance provided by the underlying library is not all that impressive, and it depends on how much work the PLC is doing and how much overhead is available for comms.

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