No, but you can make your own "heartbeat". Simply allocate a pair of tags in the PLC (integers, perhaps) for this purpose, and use a timer event in Ignition to increment one of them on some reasonable pace. Have a rung in the PLC that compares them, and when different, copies the new value to the other and restarts a timer. If the timer expires, your comms are down. I usually use a timeout 2½ times the increment period.
This approach is not specific to Omron NJ/NX processors--it works with everything that uses a polling driver.