Stopping Controller if CANOPEN connection is lost

I have a motor and controller set up to run from CANOPEN commands from remote PLC, I have found however if I am sending a run command and I disconnect the CANBUS wires the controller continues to run at the last target sent throught the CANBUS!
As a safety feature I want the controller to stop if it looses communication, I cannot find and reference to CANBUS timeouts or Network Management in microbasic scripting.

Are there any suggestions on how I could make the thing stop if my COMMS drop out?

Here's the way I'm doing it in a multi-node raw CAN system and I don't see why you couldn't do something similar in CANOpen. One of my other nodes sends a particular message at fixed intervals. The Roboteq's script uses a timer that's reset every time any Roboteq-directed message arrives. If that timer times-out without a Roboteq-relevant CAN message having been received, whether it be the one at fixed intervals or any other directed to the Roboteq, it decides that the bus has gone down, and sets the motors to 0. In other words, I just used one of the available timers as a watchdog dedicated to checking for CAN messages.
Ciao,
Lenny