Mitsubishi RJ71PB91V PROFIBUS DP Communication Module for MELSEC iQ-R Series

Product Overview

The Mitsubishi RJ71PB91V is a PROFIBUS DP communication module designed for the MELSEC iQ-R series programmable logic controllers. This module enables seamless integration of iQ-R PLCs into PROFIBUS DP networks, allowing data exchange with a wide range of PROFIBUS DP devices such as drives, remote I/O stations, sensors, and actuators. The RJ71PB91V can operate as either a DP master (Class 1 or Class 2) or a DP slave, providing flexibility in network architecture. It supports high-speed communication with transmission rates up to 12 Mbps and can handle up to 125 slaves when configured as a master, making it suitable for large scale industrial automation systems that utilize PROFIBUS DP as the fieldbus backbone.

Key Features of Mitsubishi RJ71PB91V

The RJ71PB91V supports PROFIBUS DP-V0 and DP-V1 services, enabling cyclic data exchange and acyclic parameterization or diagnostics. As a DP master, the module can automatically scan the network and configure connected slaves using GSD files, reducing commissioning time. The module features a 9-pin D-sub connector for the PROFIBUS cable, with integral bus termination that can be activated via a switch. The RJ71PB91V provides a maximum of 768 bytes of input and 768 bytes of output data per module in master mode, and 244 bytes of input and 244 bytes of output data in slave mode, accommodating demanding data exchange requirements.

Configuration of the RJ71PB91V is performed using GX Works3 engineering software, which provides a user-friendly interface for setting PROFIBUS addresses, selecting GSD files, mapping I/O data to PLC memory, and configuring diagnostic parameters. The module includes LED indicators for power, network status, and error conditions, facilitating on-site troubleshooting. The RJ71PB91V supports transparent data exchange, allowing the PLC program to read and write PROFIBUS data using dedicated instructions or direct device mapping. The module is built to industrial standards, with a wide operating temperature range and electrical isolation between the PROFIBUS interface and the PLC backplane.

Technical Specifications

• Manufacturer: Mitsubishi Electric Corporation

• Part Number: RJ71PB91V

• Series: MELSEC iQ-R

• Product Type: PROFIBUS DP Communication Module

• Protocol: PROFIBUS DP-V0, DP-V1

• Operating Modes: DP master (Class 1/Class 2) or DP slave

• Transmission Rate: 9.6 kbps to 12 Mbps (automatic detection)

• Maximum Slaves (master mode): 125

• Data Exchange (master mode): 768 bytes input, 768 bytes output

• Data Exchange (slave mode): 244 bytes input, 244 bytes output

• Configuration Software: GX Works3

• Profibus Connector: 9-pin D-sub female, switchable termination

• Diagnostic LEDs: Power, bus status, error

• Power Supply: 5 V DC from backplane

• Operating Temperature: 0 to +55 °C

• Storage Temperature: -25 to +75 °C

• Degree of Protection: IP20

• Dimensions (W x H x D): 27.8 mm x 106 mm x 110 mm

• Certifications: CE, UL, PROFIBUS International

Functional Description

The RJ71PB91V module interfaces between the iQ-R PLC CPU and a PROFIBUS DP network. In master mode, the module automatically manages the token passing protocol, polls each slave for input data, and transmits output data to them at the configured baud rate. The user program accesses the PROFIBUS data via buffer memory that is automatically mapped to PLC device addresses. The module handles error detection, watchdog supervision, and slave state monitoring. In slave mode, the module responds to read/write requests from a PROFIBUS master, making the PLC’s internal data available to the higher-level controller. The configuration is stored in the module's non-volatile memory, and the module can be replaced without reconfiguration if the same settings are retained. The built-in diagnostic functions report communication errors, slave failures, and parameter mismatches to the PLC CPU, enabling automated error handling.

Applications

The Mitsubishi RJ71PB91V is used in industrial automation systems where PROFIBUS DP is the chosen fieldbus. Typical applications include automotive manufacturing lines with distributed I/O, material handling systems with VFDs connected via PROFIBUS, process control skids with third-party PROFIBUS instruments, and retrofitting projects where existing PROFIBUS infrastructure must be integrated with new iQ-R PLCs.