KSU1 COMPONENTS The CPM (Central Processor Module) is installed inside of KSU1 to the 408M ribbon cable J4 (also labeled “To CPM”). The CPM contains: • Two serial ports, • Two music ports, • One control contact (external paging/LBC/gate control), • One external page equipment interface connection, and • Socket connectors for the KSU2 (labeled “2nd Cabinet”), MDM, and VP modules (AAM, 7271C, and 7270C). The standard 408M (part of 7201) contains: • 4 CO line ports, • 1 power failure transfer port for the first CO line circuit, • 8 digital ports, • a ribbon cable (J1, also labeled “COM4”) for connection to the COM4 module (PN 7210) in KSU1, and • ribbon cable sockets (J2 and J3, also labeled “To DPM8/APM4”) for connection of DPM8 (PN 7220) or APM4 (PN 7230) modules. The standard APM4 (part of 7201) contains four analog device ports (installed on ribbon cable J5, also labeled “APM4”). 1.2.2 KSU2 COMPONENTS The standard 408E contains: • 4 CO line ports • 1 power failure transfer port for the first CO line circuit • 8 digital ports • a ribbon cable (J1, also labeled “COM4”) for connection to the COM4 module (PN 7210), • ribbon cable sockets (J2 and J3, also labeled “To DPM8/APM4”) for connection of DPM8 (PN 7220) or APM4 (PN 7230) modules, and • a shielded cable (J4) for connection to CPM socket JP2 (also labeled “2nd Cabinet”) in KSU1.