PLX51-PBM | Rockwell Prosoft | PROFIBUS DP Modbus Serial Gateway

Product Overview

The ProSoft PLX51-PBM is a stand-alone PROFIBUS DPV0/DPV1 Master or Slave Gateway that bridges PROFIBUS DP networks to EtherNet/IP or Modbus (RTU/TCP) systems. Unlike rack-mounted modules, this DIN-rail gateway operates independently, enabling any EtherNet/IP scanner or Modbus master to access PROFIBUS devices without PLC backplane constraints. Configurable as either a PROFIBUS Master (managing up to 125 slaves) or Multiple Slaves, it offers unmatched flexibility for brownfield integration and multi-protocol environments.

Key Specifications

• Part Number: PLX51-PBM
• Product Type: PROFIBUS DP Master/Slave to EtherNet/IP or Modbus Gateway
• Series: ProSoft PLX50 Gateway Platform
• PROFIBUS Interface: 1 × RS-485 (DB9 female), DPV0/DPV1
• EtherNet/IP Interface: 2 × RJ45 (10/100 Mbps, embedded switch)
• Modbus Interfaces: Modbus TCP/IP, Modbus RTU-RS232, Modbus RTU-RS485
• Master Mode: Up to 125 PROFIBUS slaves; 2 KB device/status data
• Slave Mode: Multiple PROFIBUS slave emulation (up to 32 addresses)
• Baud Rates: 9.6 kbps to 12 Mbps
• Configuration: ProSoft PLX50 Configuration Utility
• Power Input: 10–36 VDC
• Mounting: DIN rail
• Operating Temperature: -25°C to +70°C
• Certifications: CE, UL, cULus, ATEX, IECEx

Features & Benefits

• Protocol Versatility: Bridges PROFIBUS to EtherNet/IP, Modbus TCP, Modbus RTU-232, or Modbus RTU-485
• Master/Slave Flexibility: Configurable as PROFIBUS Master or multiple Slaves per application requirements
• Embedded Ethernet Switch: Dual RJ45 ports enable daisy-chain topology without external switches
• DPV1 Messaging: Supports acyclic parameter read/write and alarm handling for intelligent devices
• Packet Capture: Built-in PROFIBUS and Modbus packet capture for advanced troubleshooting
• Web Diagnostics: HTTP server provides status monitoring, event logs, and firmware update capability

Applications

• Integrating legacy PROFIBUS devices into modern EtherNet/IP control architectures
• SCADA systems requiring Modbus TCP access to Siemens PROFIBUS field instruments
• Migration projects replacing old PLCs while retaining existing PROFIBUS I/O infrastructure
• Test benches and commissioning tools for PROFIBUS device verification

Installation Guide

1. DIN Rail Mount: Snap the PLX51-PBM onto a standard 35 mm DIN rail in an IP20 cabinet
2. Power Connection: Apply 24VDC (10–36VDC range) to the power connector
3. PROFIBUS Wiring: Connect the DB9 port to the PROFIBUS network using shielded cable
4. EtherNet/IP Connection: Connect RJ45 Port 1 to your EtherNet/IP network (or Port 2 for daisy-chain)
5. Modbus Connection (if used): Connect serial Modbus devices to the RS-232/485 terminal block
6. PLX50 Configuration: Install PLX50 Utility, discover the gateway, and select Master or Slave mode
7. GSD Management: Import slave device GSD files and configure device parameters
8. Data Mapping: Map PROFIBUS I/O data to EtherNet/IP assembly instances or Modbus registers
9. Testing: Use the utility's live list and diagnostic monitor to verify network health

FAQ

Q: Can the PLX51-PBM operate as both master and slave simultaneously?
A: No, the module operates in either Master mode or Slave mode at any given time. Mode selection is made during configuration.

Q: Do I need a PLC to use this gateway?
A: No, the PLX51-PBM is a stand-alone gateway. It can bridge PROFIBUS to EtherNet/IP or Modbus without any specific PLC backplane requirement.

Q: How many Modbus TCP connections does it support?
A: The gateway supports up to 40 TCP connections and 10 CIP connections on the EtherNet/IP side.

Q: Can I update firmware in the field?
A: Yes, firmware updates are performed via the PLX50 Configuration Utility or through the web interface using digitally signed firmware files.

Selection Tips

• Choose stand-alone PLX51-PBM over rack-mounted modules when you need protocol bridging without PLC dependency
• Verify your PROFIBUS network baud rate and ensure all slave devices support the selected rate
• For EtherNet/IP integration, confirm your scanner supports the gateway's assembly instance sizes
• Use the packet capture feature during commissioning to resolve timing or data mismatch issues
• Order the XT variant for installations in extreme temperatures or corrosive atmospheres