Multi-Tech Systems 7500 - Manual (Page 326)

Configuring the Modbus Network ION 7500 / ION 7600 User’s Guide
Page 326 Sub-Metering with a Modbus Master Technical Note
Configuring the Modbus Network
Each meter on the Modbus network must be configured correctly before it will
communicate successfully. Configuring the Modbus network has three main stages:
1. Connecting the devices physically
2. Configuring the Modbus Slave devices
3. Configuring the Modbus Master device
Connecting the Modbus Slave Devices
The Modbus Slave devices must be connected to a COM port on the Modbus
Master through an RS485 loop. (See the ION 6200 Installation & Basic Setup
Instructions for help configuring an RS485 network.)
Configuring the Modbus Slave Devices
Each slave device on the Modbus network must have a unique Unit ID. The
custom framework you will be pasting into the Modbus Master uses Unit IDs 100
through 111. For simplicity, you may want to use these Unit IDs when configuring
your Modbus network, otherwise you will have to modify the framework. Further,
all devices on the network must be communicating with the Modbus protocol and
with the same Baud rate.
Programming an ION 6200 Modbus Slave Device
1. Hold down both arrow buttons on the front panel to enter setup mode. The
default password for ION devices is zero.
2. Use the arrow buttons to find the Unit ID setting, the display will show unid.
3. Give the device a unique Unit ID.
4. Verify that the communication protocol (Prot) is set to Mod.
5. Verify that the Baud rate (bAud) is 9600.
Configuring the Modbus Master Device
1. Press the Prog button on the Modbus Master device to enter setup mode.
2. Select the COM port that is connected to the Modbus network.
3. Set the communication protocol to Modbus Master.
4. Set the Baud rate to 9600.