Main features & Overview


The GFX4-MOD module can be installed inside GFX4/GFXTERMO4 products and expands communication by means of the Modvus RTU protocol. The module has two communication channels:

  • the first channel is a serial port with Modbus RTU protocol, and connects 32 GFX4/GFXTERMO4 devices (without repeater); 
  • the second channel is a serial port with Modbus RTU slave protocol, and lets you connect to a Modbus RTU Master.

The node address is assigned by means of the two rotary switches (0...99) on the product that houses the module.

The network Master (typically a PLC) recognizes the slave node by means of this address.

The slave node recognized by the Master consists of the GFX4/GFXTERMO4 that houses the module plus the GFX4/GFXTERMO4 products connected to the Modbus serial port.

The expansion can be installed when the above-mentioned products are ordered or at a later date.



Gefran product range brochure
GFX4/GFXTERMO4-Modbus datasheet
Modbus Memory Map - GFX4, GFXTHERMO4