With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
tn3270sLusInUse
tn3270s Lus In Use
1.3.6.1.4.1.9.9.54.1.1.1.1.4
The number of LUs currently in use on the server.
Back to CISCO-TN3270SERVER-MIB MIB page.
IPHost Network monitor allows you to monitor tn3270sLusInUse on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.