The nnmsnmpnotify.ovpl script sends an SNMP Version 1 or SNMP Version 2 Trap depending on the protocol version you specify.
In general, This command sends a trap as a test to our system through the node we are chosing. For an instance, if you want to test the specific trap is coming to the system in regards to the node you specified ( to check whether any trap, an OID is disabled or not, because if disabled, then we can't see those traps onto NNMi ), is coming or not to the NNMi and if NNMi is processing with the proceedings of that particular trap.
If I want to test that if SNMP Link Down trap will get processed or how it can be processed, then I use snmpnotify command with the respecticve command :
nnmsnmpnotify.ovpl -A -v2c v2c_node .126.96.36.199.188.8.131.52.5.3