What addressable standard does the Simplex 4100 classic and + use?

The Simplex 4100 Classic and 4100+ use the MAPNET I or II Protocol.

NewAgeServerAlarm describes this in more detail.

It was replaced with IDNET, its used in the 4100U/ES 4010/ES and others.

IDNET is going to be partially phased out for the MX protocol for the New Simplex Foundation Series Panels.