Good idea for troubleshooting.
But I'm not sure a SNMP restart will send a trap.
1. Point the TS tool and run the SNMP at one of the boxes running OMSA. Be sure the result set includes the version of OMSA (Server Administrator). If you don't see the OMSA version. Full stop, we have to solve that.
2. For testing traps. Go to a box running OMSA. Fiddle with the temperature threshold. Make it go into a warning state, that will send a trap. You should see that come across in the TS tool or wireshark.
Rob