Monitor PLC Command with Return - Gateway timer?

I need to manage a monitoring of command.

Command are integer sqltag send to the PLC.
The PLC copy the value of the command into a Retrun Tag.

In ignition, I need to compare Return and Command and trigger an alarm if there are different after a timeout.

would like to use tag event script feature, but I need to monitor a timeout condition, if non return is send by PLC :scratch:

Any idea to make timer (gateway timer, no client timer)