FAZ alert handler when Firewall stops sending logs

Hey community, I am relatively new to the platform and I have been given FAZ as the main product I will be working on. I have looked in the forums and on a lot of other websites like fortiguru but I cannot find an answer. 

Is there a way to use an event handler so that if a Firewall stops sending traffic for a couple of hours to send an alert via email to a group of people? I see you cannot put a 0 in the value field of a handler so I cannot do something like if 0 alerts for "firewall" for the past 1 hours, send an alert. 

Any suggestions would be helpful. Thanks!