General Measure Technology Co. Ltd. (China) - The GMT-X4 offers several communication options, such as RS232/RS485, CAN, Ethernet (Modbus TCP/IP), and multiple fieldbus protocols. For this summary, the focus is on setting up communication through the RS485 interface.

To begin, the device is linked to a computer via its RS485 port. In the GMT-X4’s COM-1 menu, key parameters must be configured: the Slave ID (default 01), the baud rate (default 38400), the Modbus RTU protocol, the 8-E-1 data format, and the AB-CD double-word mode. The continuous transmission interval is not required for Modbus RTU.

On the PC, Modbus Poll must be set to match these values. The user identifies the correct COM port in the Windows Device Manager and enters the same Slave ID in the software. After connecting, the GMT-X4’s COM1 indicator begins blinking and the weight reading in Modbus Poll mirrors the value shown on the instrument.

This summarizes the procedure for establishing communication between the GMT-X4 and Modbus Poll through the RS485 serial interface. See the complete guide on Weighing Review.