There is not a way within the application to stop all of the robot watcher services
If you want to just suppress all monitoring and alerts you could go to each robot and put the controller into maintenance mode.
This will suspend all probes except for the controller until it is taken out of maintenance mode.
If you just want to suppress alarms I would setup a maintenance schedule for the time for all robots.
The only other way I can think of would be to script something to stop the robot watcher service on each machine.
hope this helps