MB40 & MB45 MODBUS TCP/IP Gateway
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Configuring Modbus
Modbus RTU
Serial Modbus is provided on RS485. The communications settings for this port are set 8 DIP
switches next to the D9 connector. Any changes to the switches won’t take effect until the MB40 is
power cycled.
Table 3: Modbus RTU address switches
Modbus RTU Address
Switch 1
Switch 2
Switch 3
Switch 4
1
OFF
OFF
OFF
OFF
2
ON
OFF
OFF
OFF
3
OFF
ON
OFF
OFF
4
ON
ON
OFF
OFF
5
OFF
OFF
ON
OFF
6
ON
OFF
ON
OFF
7
OFF
ON
ON
OFF
8
ON
ON
ON
OFF
9
OFF
OFF
OFF
ON
10
ON
OFF
OFF
ON
11
OFF
ON
OFF
ON
12
ON
ON
OFF
ON
13
OFF
OFF
ON
ON
14
ON
OFF
ON
ON
15
OFF
ON
ON
ON
16
ON
ON
ON
ON
Table 4: Modbus RTU Baud Rate switches
Baud Rate
Switch 5
Switch 6
2400
OFF
OFF
4800
ON
OFF
9600
OFF
ON
19200
ON
ON
Table 5: Modbus RTU Parity switches
Parity
Switch 7
Switch 8
None
OFF
OFF
Even
ON
OFF
Odd
OFF
ON
Boot-loader
1
ON
ON
1
The boot-loader is an advanced function that allows firmware updates to be deployed in the field.
