Mitsubishi Communication Module QJ71MB91 MODBUS Serial Protocol Master & Slave QJ71MB91

Description:

The Mitsubishi QJ71MB91 Communication Module is used in industrial automation systems to enable MODBUS serial communication between PLCs and external devices as both master and slave. Commonly installed in process control systems, manufacturing lines, and integrated automation setups requiring reliable serial data exchange. Maintenance teams, OEMs, and system integrators use this part for system integration, expansion, retrofit, and communication upgrades.

Applications: 

The Mitsubishi QJ71MB91 module is widely used in industrial environments where MODBUS communication is required for device interoperability. It is commonly applied in SCADA systems, energy management systems, water treatment plants, HVAC systems, and factory automation where PLCs need to communicate with sensors, drives, meters, and third-party equipment.

Technical Specifications:

• Manufacturer Part Number (MPN): QJ71MB91
• Product Type: PLC Communication Module
• Series: MELSEC-Q
• Communication Protocol: MODBUS RTU (Master & Slave)
• Interface: RS-232 / RS-422 / RS-485
• Transmission Speed: Up to 115.2 kbps
• Number of Channels: 1 serial channel
• Data Format: Configurable (parity, stop bits, baud rate)
• Mounting: Rack-mounted (Q-series base unit)
• Compatibility: Mitsubishi MELSEC-Q Series PLC
• Functionality: Supports master/slave communication modes

Common Replacements:

• Mitsubishi QJ71C24N
• Mitsubishi QJ71C24N-R2
• Mitsubishi QJ71E71-100