Published: 2025-11-12 Article source:
Hello everyone, welcome to General Measure's channel.
In this session, we will demonstrate how to communicate between the GMT-X4 and the Modbus Poll tool via the Modbus TCP/IP.
Communication Methods of GMT-X4
GMT-X4 supports various communication interfaces:
Serial Communication (RS232 & RS485)
CAN Communication
Ethernet Communication (Modbus TCP/IP)
Field-bus Communication (including PROFINET, EtherCAT, Ethernet/IP, and CC-Link IE)
In this video, we will focus on Modbus TCP/IP communication via the Ethernet port of the GMT-X4.
Hardware Connection
First, connect the Ethernet port of the GMT-X4 instrument to your computer using a network cable.
Communication Settings
On the GMT-X4 main interface, press Enter to access the Calibration Menu.
Press the Right Key to enter the Communication Parameter Menu, then press the Down Key to select 4. TCP-IP, and press Enter.
Select 4.1[Local IP], then use the Up/Down Keys to set the IP address to match the host computer.
Press Enter to confirm.
(Tip: Check your computer’s IP address and ensure the instrument is in the same network segment. The value shown in the video is for demonstration only.)
2.Subnet Mask
Press the Down Key to select [Subnet Mask], then press Enter to access the setting interface.
Use the Up/Down Keys to set the subnet mask consistent with your network configuration.
Press Enter to confirm.
(Tip: Verify your computer’s subnet mask. Ensure both are in the same network segment. The value in this demonstration is for reference only. )
3.Gateway
Press the Down Key to select [Gateway], then press Enter.
Use the Up/Down Keys to set the gateway consistent with your network environment.
Press Enter to confirm.
(Tip: Confirm the gateway of your local network and ensure consistency with the instrument settings.)
4.Connection 1
Select [Connection 1], then press Enter.
4.1 Port Number
Choose 4.4 [Port Number], use the Up/Down Keys to set the port number.
The default value is 502
Press Enter to confirm.
(Tip: Here the default value of TCP port is 502. Ensure it matches the host computer setting.)
4.2 Communication Protocol
Press the Down Key to select [Communication Protocol], press Enter, and choose Modbus/TCP.
Press Enter to confirm.
4.3 Double Word Mode
Press the Down Key to select [Double Word Mode], press Enter, and choose the required format.
The default value is AB-CD
Press Enter to confirm.
4.4 Continuous Transmission Protocol
This demonstration uses the Modbus/TCP protocol, which is not a continuous transmission protocol, the Continuous Sending Interval does not need to be set.
(Tip: This parameter prevents communication errors caused by excessive data transmission speed. Adjust only if necessary.)
If you need to enable multiple connections (Connection 2–Connection 6), repeat the same steps as for Connection 1.
4. PC Software Settings
After completing the instrument configuration, open your computer and set up Modbus Poll as follows:
In Modbus Poll, click Connection → Connect.
Configure the parameters, set them as same as the instruments are.
Connection Type: Modbus TCP/IP
IP Address: Enter the same IP as set on the GMT-X4
Server Port: 502
Click OK to connect.
When communication is successful, the LAN indicator on the GMT-X4 will flash, indicating normal communication.
The weight value displayed on the GMT-X4 will match the data shown in Modbus Poll.
That's how you set up communication between the GMT-X4 and Modbus Poll via the Modbus TCP/IP.
In the next video, we will demonstrate how the GMT-X4 communicates with a PLC using the PROFINET protocol.