Different backplanes are used for connectivity and distribution of signals in MRT, which are divided into two main groups of Main and Lower Backplanes.
Main backplane is used for connectivity between modules in digital section. There are three types of main backplanes available: BPM912, BPM912L, BPM912M and BPM912R.
Main Backplane provides connection between I/O cards and RTU module (which is responsible for controlling the system) in this system. Main backplanes are connected together by D-SUB 25 connectors, which include BACKPLANE BUS signals. Their power is connected through distinct careers to 12V power.
Lower backplane is used for connectivity between modules and input/output signals .Lower backplane is in modular form in this system, is substitutable with new lower backplane with the least switching time, and is divided to two types of BPL921S, BPL922S.