With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
tn3270eRtDataClientAddress
tn3270e Rt Data Client Address
1.3.6.1.2.1.34.9.1.2.1.2
Contains the IP address of the TN3270 client being monitored. A zero-length octet string is used if aggregate data is being collected for the client group.
Back to TN3270E-RT-MIB MIB page.
IPHost Network monitor allows you to monitor tn3270eRtDataClientAddress on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco wireless switches right now.