The Mitsubishi Electric A1SX81 DC digital input unit is a MELSEC-A series input module designed to interface external devices with Mitsubishi PLCs by reading digital on/off signals and feeding them into the controller. This DC input unit is part of the MELSEC-A family and is used to sense binary input states from sensors, switches, and other field devices in automation projects. The A1SX81 designation identifies this specific input module within the MELSEC-A lineup and defines its compatibility with MELSEC-A controllers and I/O networks.
