Mitsubishi A1SX81-S2 Input Unit Module DC 24V 7mA A1SX81S2

Description:

The Mitsubishi A1SX81-S2 is a digital input module designed for the MELSEC-A series programmable logic controllers, providing reliable signal acquisition from field devices in industrial automation systems. Commonly installed in control panels, production lines, and machine automation systems, it processes discrete input signals from sensors, switches, and relays. Maintenance teams and system integrators use this module for system expansion, input signal monitoring, and replacement of legacy PLC input modules.

Applications:

The Mitsubishi A1SX81-S2 is used in industrial automation environments requiring stable and accurate digital input handling. Typical applications include assembly lines, conveyor systems, packaging machines, and process control systems where multiple field inputs must be monitored and integrated into PLC logic.

Technical Specifications:

• Manufacturer Part Number (MPN): A1SX81-S2
• Product Type: Digital Input Module (PLC I/O Module)
• Series: MELSEC-A Series
• Number of Inputs: 32 points
• Input Type: DC input (sink/source compatible)
• Rated Input Voltage: 24 VDC
• Input Current: ~7 mA per point (typical)
• Isolation Method: Photocoupler isolation (typical for A-series)
• Wiring Method: Terminal block connection
• Internal Current Consumption: —
• Weight: ~0.4 lbs (~0.18 kg)
• Compatibility: MELSEC-A and AnS series base units
• Status: Discontinued / legacy module

Common Replacements:

• Mitsubishi A1SX81 (standard variant)
• Mitsubishi A1SX82 (higher input capacity)
• Mitsubishi QX41 (Q-series migration option with adapter)