QX81 32-Point Digital Input Module 24V DC Source | Mitsubishi

The Original New Mitsubishi QX81 is a 32-point digital input module (source/negative common type) from the MELSEC-Q series, designed for high-density signal acquisition in industrial automation systems. It accepts 24 V DC input signals with a rated input current of approximately 4 mA and features a configurable input response time of 1, 5, 10, 20, or 70 ms (default 10 ms). The module uses opto-isolator insulation between input terminals and the PLC power supply, and connects via a 37-pin D-sub connector. As part of the MELSEC-Q QnU series, it integrates directly into Q series base units and is compatible with QnU, QnH, and other Q series CPU modules. Its compact 27.4 mm width and 98 × 90 mm footprint make it suitable for space-efficient control panel installations.

Core Engineering Highlights:
32 digital inputs (24 V DC, source/negative common type) | 4 mA rated input current | Configurable response time: 1 / 5 / 10 / 20 / 70 ms (default 10 ms) | 32 points/common | Opto-isolator insulation | Occupied I/O points: 32 | 37-pin D-sub connector | 0.075 A internal current consumption | 0.16 kg weight | IP2X protection

Key Features:

• Original New Mitsubishi QX81 module

• 32 digital input points, 24 V DC source type (negative common)

• Approximately 4 mA rated input current per point

• Configurable input response time: 1 / 5 / 10 / 20 / 70 ms or less (default 10 ms, set via PLC parameter)

• ON voltage/current: 19 V or more / 3 mA or more

• OFF voltage/current: 11 V or less / 1.7 mA or less

• Opto-isolator insulation between input terminals and PLC power supply

• 32 points/common configuration

• 37-pin D-sub connector for high-density wiring

• Occupied I/O points: 32 (I/O assignment: Input 32 points)

• Internal current consumption (5 V DC): 75 mA (0.075 A, TYP. all points ON)

• ON display LED per input point for easy status verification

• Compact 27.4 mm width for high-density panel mounting

• RoHS compliant

Applications:

• High-density digital signal acquisition from sensors, limit switches, and pushbuttons

• Factory automation and production line control

• Conveyor and material handling systems

• Packaging machinery and assembly line monitoring

• Process control and machine automation

• Distributed I/O systems with MELSEC-Q series

Technical Specifications:

System Compatibility:

• Compatible with Mitsubishi MELSEC-Q series base units (main base and extension base)

• Compatible with Q series CPU modules including QnU, QnH, QnPH, QnPRH, and Q00J/Q00/Q01 series

• Installs in any Q series I/O slot via the Q series backplane bus

• Programming and configuration via GX Works2 or GX Developer engineering software

Related Products:

• QX81-S2 – 32-point DC input module with 6 mA rated input current (higher sensitivity)

• QX81-C – 32-point DC input module with conformal coating (harsh environments)

• QX80 – 16-point DC input module (source type, screw terminal)

• QX41 – 32-point DC input module (sink type, FCN connector)

• QY81P – 32-point transistor output module (sink type, 0.5 A)

• Q61P – Power supply module for MELSEC-Q base units

• Q38B – 8-slot main base unit for Q series

• RX41C4 – Successor module for MELSEC iQ-R series (recommended for new designs)

• GX Works2 – Engineering software for MELSEC-Q series

PLC ERA is an independent industrial automation distributor supplying genuine Original New products through established global supply channels. All products are factory sealed when applicable and undergo quality inspection prior to shipment. Mitsubishi, MELSEC, and MELSEC-Q are trademarks of Mitsubishi Electric Corporation.