ProSoft PLX31-EIP-MBS4 Product Description

PLX31-EIP-MBS4 is a 4-port independent industrial communication gateway launched by ProSoft, enabling high-speed bidirectional data conversion between EtherNet/IP networks and Modbus serial (RTU/ASCII) devices. It is specifically designed for large-scale integration of Modbus instruments, sensors, PLCs, etc. in Rockwell Automation systems, supporting DIN rail installation, full electrical isolation, SD card configuration backup, and multi-port parallel polling.

I. Model Interpretation

PLX31: Independent high-performance network series

EIP: EtherNet/IP protocol side (Rockwell standard industrial Ethernet)

MBS4: Modbus Serial (serial) protocol side, 4 independent serial ports (RS-232/422/485)

Core Positioning: 4-port Modbus serial ports, EtherNet/IP Class 1/3, configurable master/slave stations, 10,000-byte data cache, 2500V optical isolation, DIN rail, SD card backup, 400 devices connected to ProSoft Technology Inc.

II. Core Hardware Specifications

Mechanical and Power Supply

Installation Method: DIN rail standard installation

Power Supply: 10~36 VDC (nominal 24 VDC), 300 mA @ 24 VDC

Size: 13.67 × 5.05 × 11.13 cm

Weight: Approximately 0.22 kg

Ethernet Interface (EtherNet/IP)

Ports: 1 × 10/100 M RJ45, full / half duplex

Isolation: 1500 Vrms electrical isolation

Protocol Support: EtherNet/IP Class 1 (implicit I/O), Class 3 (explicit messages)

Connection Number: 8 Class 1 I/O connections, 5 Class 3 server connections

ProSoft Technology Inc. Maximum I/O Size: 248 In / 248 Out

Minimum RPI: 5 ms / connection ProSoft Technology Inc.

Serial Interface (Modbus Serial, 4 Ports)

Ports: 4 × Independent RS-232/422/485 (software configurable) ProSoft Technology Inc.

Isolation: 2500 Vrms optical isolation (UL 1577)

Protocol: Modbus RTU, Modbus ASCII

Baud Rate: 1200 ~ 115200 bps

Mode: Each port independently configured as Modbus master or slave ProSoft Technology Inc.

Master Station Capability: Each port supports 100 user-defined Modbus instructions, totaling 400 instructions

Slave Station Address: 1~247

Data and Storage

Internal Database: 10,000 × 16-bit words (bidirectional data exchange area) ProSoft Technology Inc.

Configuration Storage: Built-in Flash + SD card slot (configuration backup / restoration) ProSoft Technology Inc.

LED Indicators: PWR, CFG, ERR, FLT, NS, MS, 4×COM Status

Environment and Certification Operating temperature: -25°C ~ +70°C

Storage temperature: -40°C ~ +80°C

Humidity: 5% ~ 95% (no condensation)

Shock resistance: 5G @ 10~150 Hz

Impact resistance: 15G (operation), 30G (non-operation)

Certifications: CE, UL/cUL, RoHS, DNV, ABS

III. Core Functions and Working Principle

1. Protocol Conversion Mechanism

Bidirectional data forwarding: EtherNet/IP ↔ Modbus Serial automatic mapping

Data buffer: 10,000-word shared memory, achieving protocol decoupling and high-speed exchange by ProSoft Technology Inc

4-port independent control: Each port parameters, modes, instruction lists are completely independent

Master/Slave flexible configuration

Master station mode: Active polling of Modbus instruments, inverters, PLCs

Slave station mode: As a Modbus slave station accessed by third-party SCADA/PLC

2. Functions on EtherNet/IP side

Class 1 implicit I/O: Data exchange with ControlLogix/CompactLogix real-time I/O

Class 3 explicit messages: Support MSG instructions reading and writing, program control by ProSoft Technology Inc

EDS additional configuration file: Direct integration with RSLogix/Studio 5000, configuration without programming by ProSoft Technology Inc

ProSoft Discovery Service: Cross-segment discovery module, modifying IP by ProSoft Technology Inc

Data priority: Multiple I/O connections can set different RPIs to optimize bandwidth by ProSoft Technology Inc

3. Functions on Modbus side (Master station)

400 instruction queues: Support function codes 1/2/3/4/5/6/15/16

Scheduling: Periodic / triggered / conditional polling to optimize bus load by ProSoft Technology Inc

Error handling: Automatic retry, timeout, isolated faulty nodes by ProSoft Technology Inc

Address mapping: Free mapping of Modbus address ↔ internal database

Floating point support: Enron, Daniel floating point protocol

4. Reliability and Maintenance

Full electrical isolation: Ethernet, serial port, power supply three-terminal isolation, anti-interference, lightning protection

SD card backup: Configuration quick cloning, rapid fault recovery by ProSoft Technology Inc

Web diagnosis: Built-in Web server, remote status monitoring, log viewing

Hot swapping: Support for on-site maintenance, no interruption of system operation

Safety switch: Hardware configuration lock to prevent accidental modification (v1.04+)

IV. Core Advantages

1. Industrial-grade stable and reliable

Wide temperature range, isolation, no fan, suitable for extreme industrial sites

2500V photoelectric isolation, completely solving ground potential difference, strong electromagnetic interference

Independent gateway: Does not occupy PLC slot, does not increase PLC scanning load

2. Rockwell deep compatibility

Native support for EtherNet/IP Class 1/3 by ProSoft Technology Inc EDS File Integration: One-click Configuration for ProSoft Technology Inc. in RSLogix/Studio 5000

Zero PLC Programming: Automatic data mapping, no modification of control logic

3. 4-port High-Density Integration

4 Independent Serial Ports, RS-232/422/485 switchable for each port by ProSoft Technology Inc.

Single Gateway Connects 400 Modbus Devices, Significantly Reducing Gateway Quantity

400 Instructions, 10,000 Data Areas, Meeting Requirements for Large-scale Systems by ProSoft Technology Inc.

Parallel Polling of Multiple Ports, System Response Speed Increased by 4 Times

4. Easy to Use and Maintain

DIN Rail, Plug-and-Play

SD Card Configuration for Backup, Batch Deployment, and Quick Replacement by ProSoft Technology Inc.

LED + Web Dual Diagnosis, Precise Fault Location

Cross-Subnet Configuration Tool, Simplifying Network Deployment by ProSoft Technology Inc.

V. Typical Application Scenarios

ControlLogix/CompactLogix for Large-scale Integration of Modbus Terminals (Flowmeters, Pressure Gauges, Sensors)

Multiple Modbus Frequency Converters and Servo Controllers in Production Lines for Centralized Control

Upgrade of Old Modbus Systems to Access EtherNet/IP Network

SCADA System Monitors Distributed Modbus RTU Devices via EtherNet/IP

Interconnection of Multiple Manufacturers' Devices (Rockwell ↔ Modbus Protocol Devices)

Remote I/O System: 4 Serial Ports Cover Multiple Area Devices, Reducing Wiring Costs

VI. Summary

PLX31-EIP-MBS4 is an industrial-grade standard gateway for large-scale interconnection of EtherNet/IP and Modbus serial devices. With 4 independent RS-232/422/485 ports, single gateway for 400 Modbus devices, dual connections of EtherNet/IP Class 1/3, 10,000-byte data cache, 2500V full optoelectrical isolation, SD card configuration for backup, wide-temperature industrial-grade design as core advantages, it perfectly realizes seamless data connection between Rockwell Control System and various Modbus serial devices, is a highly reliable and high-performance solution for high-density protocol conversion, system upgrade of old systems, and multi-device integration in industrial sites, significantly reducing system costs and complexity.