Problem to Connect HMI with PLC


Thread Starter


In my project the distance between PLC and HMI
is 11 meters and I make the XBTZ968 by myself, but when the HMI (XBTF032110) connects to the PLC (TSX3721001), the message "UNABLE TO WRITE VARIABLE" appears.

Any advice?

10M is pushing your luck. The TER/Aux port is limited to 10M due to the current output of the port. Try a shorter cable, 2M for example. If it works then you know for a fact it's the cable length, or maybe cable type.

Strictly speaking, you should use a TSXSCP114 PCMCIA com card to go up to 1200M. I assume you are using standard Unitelway coms, and that you only have the HMI connected on the network. Check the Micro catalogue.