GW-7838-M Modbus TCP Server to M-Bus Master Gateway


Key Features

  • Supports M-Bus standard: EN-13757, CJ/T -188
  • Supports Modbus TCP/RTU function code 0x03 and 0x04 to read Meter data
  • Default M-Bus port data format: Data bit 8, Parity Even, Stop bit 1
  • Supports up to 100 M-Bus slaves
  • M-Bus over current protection
  • Short-circuit protection on the M-Bus
  • Update firmware from serial port
  • Watchdog inside


M-Bus (Meter-Bus) is a communication interface widely used in various meters, such as electricity meters, water meters, heat meters, etc. Ease of installation (two-wire system includes power and communication function) and robustness are the most important features. M-Bus has its own physical layer and protocol. Therefore, it is usually switched to other systems, such as Modbus, to facilitate the overall application.

In the field of automation, Modbus TCP/RTU is one of the most common communication standards. ICP DAS developed the gateway GW-7838-M for Modbus TCP/RTU to M-Bus, allows the direct transmission of meter data to a control system using Modbus TCP/RTU. The ICP DAS GW-7838-M supports operating up to 100 devices on the M-Bus. After an initial configuration by M-Bus utility, GW-7838-M will read out the meters data autonomously. The PLC or PC as a Modbus TCP/RTU client can access meter data via a TCP/RS-232 connection easily.


The M-Bus (Meter‐Bus) is a bus optimized for the reading of measurement instruments like: energy counters, hot and cold water counters, gas, pressure, sensors and actuators, etc.….