systems. Versions of the Modbus protocol exist for serial lines (Modbus RTU and Modbus ASCII) and
for Ethernet (Modbus TCP).
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12.5.2 What can I do with it?
Modbus-communication with USH-9 allows reading of measurement values and device information
by a Modbus master. Additionally, the basic RS-485 port settings can be written to the USH-9.
12.5.3 Wiring
For Modbus communication the USH-9 is wired according to the table below.
Modbus
Connector MAIN
Connection wire
Description
Common
Pin 1
White
GND
D1 - B/B
Pin 4
Yellow
RS-485 A
D0 - A/A
Pin 5
Grey
RS-485 B
Table 21
Modbus wiring
NOTE
If the USH-9 is operated with multiple Modbus devices within the same
network, termination resistors may be required. Please contact Sommer Mess-
technik for details.
12.5.4 Configuration
Follow the instructions below to change the communication of a Sommer-device (in this example a
RG-30) to Modbus:
1. Connect the USB to RS-485 converter to the data cable of the Sommer-device and a USB port
on your PC.
2. Connect the sensor to a power supply with the specified rating.
3. Start the Commander software on your PC.
4. Establish a connection to the Sommer-device.
5. Download the sensor’s parameters in the
Parameters (F2)
tab and save the parameter list on
your PC.
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http://www.simplymodbus.ca/FAQ.htm
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Manual
