Yeah it was an issue on the Beckhoff end. The CX9xxx series does not support the security options of OPC UA, so once I set it to None/None in Ignition, everything worked fine.
I use Beckhoff OPC UA Server, i 've trouble to write tag from ignition.
read is OK.
from the opc ua client from beckhoff, read and write are both OK.
Any idea or tips for the settings in ignition or beckhoff for the write operation from ignition ?