Technical Parameters Basic Information Brand: ALSTOM / Converteam Part Number: MPA157 Form Factor: Standard 3U slide-in rack pluggable digital I/O module Matching peripheral boards: MVTU/MVTT traction master CPU, MVAJ/MVAX/MVUA high voltage auxiliary power supply, PRS12 series DC110V backup power, CDG11/MCGG analog sampling boards, AP5427A/AT315MR IGBT gate drive boards, MCAA/TRVC TCMS communication gateway boards Application: European urban metro & light rail traction converter, vehicle safety chain acquisition, auxiliary equipment status detection, external contactor/valve control signal output Control Power Supply Rated operating voltage: DC 24V vehicle control power Operating voltage range: 18 VDC ~ 30 VDC Max power consumption: 7.8 W Input protection: Reverse polarity blocking diode, multi-stage TVS surge filter, input overcurrent fuse, undervoltage lockout protection Digital Input Channels (Opto-Isolated DC24V) Total input channels: 24 channels isolated digital inputs Signal type: DC24V active high/low contact feedback Typical collected signals: Emergency stop loop state, high-voltage cabinet door interlock, earthing switch position, pantograph up/down feedback, cooling fan running/fault, pre-charge contactor status, braking system feedback, maintenance mode switch Circuit feature: Each channel independent current-limiting resistor + surge suppression, complete galvanic isolation between field signal and internal logic circuit Digital Output Channels (Relay Isolated) Total output channels: 16 relay contact outputs Contact specification: DC24V/5A resistive load per channel Typical control objects: High-voltage contactor coil, cooling fan control, fault indicator light, traction enable relay, braking command output, maintenance alarm signal Circuit feature: Built-in freewheeling diode for inductive load suppression, relay surge absorption circuit to avoid back EMF damage to board logic Internal Rack Communication High-speed proprietary backplane bus for bidirectional real-time data exchange with traction master CPU: upload all digital input status and fault interlock flags; receive master control output instructions to drive each relay output channel. Mechanical Specifications Overall dimension: H130 mm × W98 mm × D220 mm PCB protection: Full acrylic conformal coating, anti-moisture, anti-corrosion, anti-dust, anti-mold Front panel LED indicators: 24V Logic Power OK, Rack Bus Link Normal, General Interlock Fault, Group Input Status LED, Group Output Action LED Fastening structure: Anti-looseness lock buckle, stable electrical contact under long-term vehicle running vibration and shock Railway Environmental & EU EN Compliance Operating ambient temperature: -25 ℃ ~ +70 ℃ Storage & transport temperature: -40 ℃ ~ +85 ℃ Relative humidity: 5% ~ 95% non-condensing Vibration test standard: IEC 61373 railway rolling stock Shock resistance: 12g half-sine wave impact test EMC standard: EN 50121-3-2 railway vehicle electromagnetic compatibility Fire safety grade: EN 45545-2 HL2 low smoke, low toxicity flame retardant material