Am i going mad, i have been fighting this all day,
I have restructured my PLC Address to provide a consistent string of registers, and changed my offsets.
When Looking at the comm monitor & wireshark, the communications are flaky,
with regular 'Port Locked'
WireShark reports a occasional 'TCP Retransmission' from the PLC forcing a 0.2 second delay is the monitoring.
But the original packet arrived at the DAQ Machine Correctly??
When DAQ attempts to Write to a register if i get the timing wrong , Lock up in a endless 'Port Locked' Loop
and have to shutdown to restart the TCP Connection.
As if DAQ Tries to perform an instantaneousness Write irrelevant that the port is active.
Also when looking at the Comm Monitor the same Block of Data is requested in succession as if queued up.
The PLC is a High Speed Motion controller with a good response time and has in the past handled far more tags > 1000 with an update of 0.1 Seconds. Utilizing 4 Simulations TCP Connections.
One option is the disable polling before running any sequence that writes, but due to the number of tags this may be painful:(