Uses for the D298M over a D298S or D278S popited base?
D278S 12 volt popit base.
D298S 24 volt popit base.
The D298M is a 24 volt popit base that provides connections for up to 19 supervised circuits two-wire slave detectors (D287 2-Wire Base with D285 Smoke Head or D285TH Smoke Head with 135 degree heat sensor) reporting to the master address.
The D298M is used over the D298S to conserve popit addresses on a large system.