Due to a trademark infringment issue, the Westinghouse / Cutler-Hammer / Eaton IQ Energy Sentry II was renamed the IQ Multipoint Energy Submeter II (IQMES II). If you are looking for protocol information for the IQ MES II, be sure and also search for old literature still scattered around that use the obsolete Energy Sentry name.
For example, INCOM protocol information for the IQ MES II can be found starting on page 233 in the IMPACC Protocol Guide (Instruction Leaflet 17384): http://www.eaton.com/ecm/groups/public/@pub/@electrical/documents/content/il17384b.pdf#page=233 (http://www.eaton.com/ecm/groups/public/@pub/@electrical/documents/content/il17384b.pdf#page=233)