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Configuring the Model 1133A
7.7
Configure Ports – Modbus
Modbus is a serial communications protocol published by Modicon in 1979 for use with its
programmable logic controllers (PLC’s), and is now the most commonly available means of
connecting industrial electronic devices. To configure the 1133A to communication using Modbus
protocol, you will need to configure the desired port to use it and then set some simple configuration
options.
The 1133A will respond to polling of specific Modbus commands, whether by a software
application or specialize device. PSCSV does not communicate using Modbus.
1. Open the Configure Ports window and select the port you wish to use on the left panel. On
the right panel choose Modbus protocol. The configuration screens for Communication Ports
1 and 2 differ somewhat from Ethernet. Communication Port 1 is selected in Figure 7.9. For
Communication Port 1 and 2, select Protocol Modbus. For Ethernet, select Modbus ON.
Figure 7.9: Selecting MODBUS in COM 1 Settings
2. After selecting the protocol for the port, select the Modbus item on the left panel. Choose
the Address value (See figure below) and click OK.
3. Notice that in Figure 7.9 that RTU Mode is selected (next to arrow cursor). The other choice
is ASCII Mode.