With IPHost Network Monitor you can run simple snmp requests against a Fortinet device in your network.
fgApIMUpTime
fg Ap IM Up Time
1.3.6.1.4.1.12356.101.10.105.1
Up-time of the IM proxy, in seconds
Back to FORTINET-FORTIGATE-MIB MIB page.
IPHost Network monitor allows you to monitor fgApIMUpTime on Fortinet device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Fortinet firewalls right now.