Kevin, the Optimistic Writes worked but I am thinking we may be missing else… In the same setup as above, we are finding that if a tag script writes values, the Tag Group Optimistic Write timeout and value changes back to PLC’s value, “0” in this case. The PLC never gets the value… but here’s the crazy thing… I have a debug view with sliders binding to the same tags, when they are modified the writes are seen on the PLC… The script updates the derived tags, JSON values to the OPC tags, all the visualizations but not in the PLC. Any thoughts on what I maybe missing or where to go looking for the issue?