Product Description
. . . . . The M300MJ Monitor Module is intended for use in intelligent, two-wire systems where the individual address of each module is selected using the built in rotary switches. It provides either a 2-wire or 4-wire fault tolerant initiating device circuit (IDC) for normally open contact fire alarm and supervisory devices, or either normally open or normally closed security devices. The module has a panel controlled LED indicator. The M300MJ can be used to replace an M500MJ module in existing systems.. Johnson Controls. Johnson Controls. M300MJ.