Thank you Colin! I suspected that field was the one I needed but needed clarification.
One follow-up. I take it when the max session time is met or the idle timeout time has been met a log would be generated on the controller for me to research? We do have automatic connect, so you are right about the clients may never disconnect as they would reconnect again. That did not register with me until you mentioned it.
With automatic reconnect I am introducing a new challenge in trying to find the best time to upgrade my controllers. If I see events of inactivity occur even though they are connected, I can at least tell they are inactive and can upgrade my controllers and their session fails over to the standby node without affecting their work.