I am using a Siemens 1500 PLC and the onboard OPC UA server. I have structured my UDTs to contain a single OPC tag which is subscribed to the corresponding UDT on my PLC. The individual elements of my UDT are all derived tags using read/write expressions with jsonGet() and jsonSet() expressions back to the single OPC tag. This is done to reduce communication load with the PLC. I’ve done this successfully using versions up to 8.1.1.
Then when I upgraded to 8.1.3 - If I wrote to each tag individually, I would still have no issues. However, when I use a function like system.tag.writeBlocking() to write to multiple tag paths in short succession (all derived tags) only the write to the last tag path succeeds.
When I was using 8.1.3 I was advised by support to add the following to my gateway config file:
in order to restore the old functionality that I was accustomed to. This seemed to solve my issue. Now using both 8.1.4 and 8.1.7 with the same change to the gateway config file my writes are failing again - only the last tag write succeeds. What else can I try to be able to write to multiple tags derived from a single OPC UA tag in short succession?