Hardware reference guide

DIO
234
35013379 11/2011
LED Indicators and Descriptions
The following figure shows the LED panel.
The following table shows the DIO LED indicators and descriptions.
Rear Panel Switches
Two rotary switches (refer to the illustration and table that follow) are located on the
rear panel of the CPU. They are used for setting Modbus Plus node addresses for
the unit.
LED Descriptions
LEDS Color Indication when On
Ready Green The module has passed power-up diagnostics.
Fault Red A communications error exists between the DIO module and one or
more I/O modules or an output module is not being written to over the
Modbus Plus network.
Pwr ok Green Bus power is present.
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).