ProSoft PLX31-MBTCP-MBS | Modbus TCP/IP to Serial Gateway

The ProSoft PLX31-MBTCP-MBS is a high-performance industrial gateway designed for seamless communication between Modbus TCP/IP and Modbus Serial (RTU/ASCII) networks. It allows a Modbus TCP/IP Client to control Modbus Serial devices, or vice versa, acting as a bridge between Ethernet-based systems and legacy serial infrastructure.

Technical Specifications

Ethernet (Modbus TCP/IP) Performance

Serial (Modbus Master/Slave) Performance

Physical Characteristics

Installation Guidelines

1. Power Wiring:

   The unit requires a 24 VDC power source. Ensure the polarity is correct when wiring the terminal block to avoid damaging the internal circuitry.

2. Serial Port Selection:

   The serial port is versatile (RS-232/422/485). Ensure the jumpers or software settings match your physical wiring. For RS-485 long-distance runs, ensure proper 120-ohm termination is applied at the end of the line.

3. Network Configuration:

   Use the ProSoft Configuration Builder (PCB) software to set the IP address. Ensure the gateway is on the same subnet as your Modbus TCP/IP Master (Client).

4. Mounting:

   The unit is designed for standard DIN-rail mounting. Ensure adequate clearance for airflow, especially in high-temperature environments.

Frequently Asked Questions (FAQs)

Q1: Can this gateway support both Modbus RTU and Modbus ASCII?

A: Yes. The serial port can be configured for either RTU or ASCII messaging, depending on your field device requirements.

Q2: What is the difference between MBAP and Encapsulated servers?

A: MBAP (Modbus Application Protocol) is the standard header used over TCP/IP (Port 502). Encapsulated Modbus refers to standard serial packets wrapped in a TCP/IP envelope, often used by legacy software drivers.

Q3: How many serial devices can I connect to one PLX31-MBTCP-MBS?

A: In RS-485 mode, you can connect up to 32 devices (standard load) to the serial port, provided they all use the same baud rate and parity settings.

Q4: Is the configuration stored if power is lost?

A: Yes. The configuration is stored in non-volatile memory and is automatically reloaded upon power-up.

Q5: What diagnostic tools are available?

A: The unit features front-panel LEDs for Power, Ethernet Link/Activity, and Serial Transmit/Receive status. Additionally, the ProSoft Configuration Builder provides a "Diagnostic" window for real-time traffic monitoring.