Hardware reference guide

DIO
35013379 11/2011 231
Rear Panel Switches
Two rotary switches (refer to the following illustration and table) are located on the
rear panel of the CPU. They are used for setting Modbus Plus node addresses for
the unit.
SW1 (the top switch) sets the upper digit (tens) of the address; SW2 (the bottom
switch) sets the lower digit (ones) of the address. The illustration below shows the
correct setting for an example address of 11.
The following table shows the node addresses of the SW1 and SW2 switches.
NOTE: If "0" or an address greater than 32 is selected, the RIO module displays a
flashing Error A and Error B LED to indicate an error condition. Only addresses 1-
32 are valid.
Modbus + Green Communications are active on the Modbus Plus port.
Error A Red Communication error on the Modbus Plus Channel A (dual cable only).
Error B Red Communication error on the Modbus Plus Channel B (dual cable only).
LED Descriptions
LEDS Color Indication when On
SW1 and SW2 Switches
Node Address SW1 SW2
1 ... 9 0 1 ... 9
10 ... 19 1 0 ... 9
20 ... 29 2 0 ... 9
30 ... 39 3 0 ... 9
40 ... 49 4 0 ... 9
50 ... 59 5 0 ... 9
60 ... 64 6 0 ... 4