How to set a Trigger to fire when i lost SNMP contact?

[bassualdo]

Hello fellows! Can someone help me with that?

I need to set a trigger to fire a alarm when i lost SNMP contact with a serial interface of a cisco router.

I already have all the monitoring working but i dont know how to set the condictions to this trigger to work.

I know that may be simple because when the interface is UP it keeps returning Value=1. But i didn't get any help with the manual about how to set the trigger to fire when it stops to send Value=1.

[bassualdo]

Resolved

i used the predefined expression

"N NOT X, where X is 1 - no data received during period of T seconds, 0 - otherwise"

then a set the period T = 60s and left the N=0

It works fine!