Chapter 4 Using Modbus Functions (Communicating With Modbus Devices); Using Modbus/Tcp To Enable Other Devices To Read Data From And Write Data To The Gx/Gp (Modbus Server Function); Setting Basic Network Communication Conditions; Configuring The Modbus Server Function - YOKOGAWA GX20 User Manual

Chapter 4 Using Modbus Functions (Communicating with Modbus devices)
4.1 Using Modbus/TCP to Enable Other Devices to
Read Data from and Write Data to the GX/GP
(Modbus server function)
4.1.1 Setting Basic Network Communication Conditions
Description
4.1.2

Configuring the Modbus Server Function

Description
IM 04L51B01-01EN
The Modbus function is used by the GX/GP and external Modbus devices to perform
communication and data reading and writing.
The GX/GP can operate as a Modbus server. The maximum number of simultaneous
connections is 4.
Other devices (Modbus client devices) can carry out the following operations on the GX/GP.
• Read I/O channel and math channel (/MT option) data
• Read communication channel (/MC option) data
• Write data to communication channels
• Start and stop recording, write messages, and perform other operations
• Load the recording start/stop condition, message strings, and other types of data
Modbus server
GX/GP
Modbus client device
• Obtain the IP address automatically
• Set the IP address manually (when automatic IP address assignment is set
to Off)
For details on the settings, see page 1-180 in section 1.21.1, "Setting Basic Communication
Conditions".
Enabling the Modbus Server Function
For details on the settings, see page 1-194 in section 1.21.9, "Setting the Server Functions
to Use (FTP, HTTP, SNTP, MODBUS, GENE, DARWIN compatible communication)".
Applying Modbus Connection Limits
Set this function to limit the IP addresses that can connect to the GX/GP Modbus server
function.
You can register up to 10 IP addresses.
For details on the settings, see page 1-193 in section 1.21.8, "Limiting the Connection to
the Modbus Server (GX/GP)".
Ethernet
GX/GP internal register
Input register
3XXXXX
Hold register
4XXXXX
Client
Command
Read
Read
Read
Read
Write
Write
4-1
1
2
3
4
5
App
Index