If my robot's detection is ever lost do to distance and it is in a harmful environment (H2S) that I can't go into, isn't the robot "technically" trapped.

I know that you can run script that can automatically connect to the EZ-B. But can you run script that does almost the opposite and detects when connection is lost. Meaning that if my rover 5 lost connection and now is to far for me to reconnect, can you setup a way that when disconnected it runs a script command and drives closer to you then is disconnected, etc. (I know to run the EZ-B it needs a computer so it seems non-doable, but is there a similar way like this:

Ex: could the signal when becoming low be used as a variable and just before reaching 0 it stops and warns you that you will lose connection if you drive in that direction anymore.

I am planning to use an XBee which will have a good distance, but I want to be careful b/c loosing my robot after hours of work would really suck and the only way out would be building a new one with more range that would be capable of pulling it back.