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
| Category |
Specification |
| Manufacturer |
ProSoft Technology |
| Model Number |
PLX31-MBTCP-MBS |
| Product Type |
Modbus TCP/IP to Modbus Serial Gateway |
| Power Supply |
24 VDC nominal (10 to 36 VDC) |
| Power Consumption |
24 VDC @ 100 mA |
| Operating Temp |
-25°C to 70°C (-13°F to 158°F) |
Ethernet (Modbus TCP/IP) Performance
| Feature |
Capacity |
| Supported Clients |
Up to 10 |
| Supported Servers (MBAP) |
Up to 5 |
| Supported Servers (Encapsulated) |
Up to 5 |
| Command List |
Up to 160 fully configurable Client commands |
Serial (Modbus Master/Slave) Performance
| Feature |
Capacity |
| RS Interface |
RS-232, RS-422, and RS-485 (Hardware selectable) |
| Baud Rate |
110 baud to 115.2 kbps |
| Parity |
None, Even, Odd |
| Data Size |
7 or 8 bits |
| Node Address |
1 to 247 (Software selectable) |
| Command List |
Up to 100 commands per Master port |
| RTS On/Off Delay |
0 to 65535 milliseconds |
Physical Characteristics
| Item |
Data |
| Dimensions (L x W x H) |
5.05 cm x 11.13 cm x 13.67 cm |
| Unit Weight |
0.5 kg |
| Shipping Weight |
1.5 kg |
Installation Guidelines
-
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.
-
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.
-
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).
-
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.