12.1. Auxiliary Input/Output (I/O) Board

The Auxiliary I/O Board (A4) is an optional component that mounts near the top of the heat sink on the left side of the ATevo . It is equipped with:

• six (6) relays
• four (4) generic Binary Inputs
• four (4) generic Analog Inputs
  

When supplied, the Auxiliary I/O Board (A4) is electrically connected to and mounts on the Power Board (A2). The Auxiliary I/O Board (A4) links to the Main Control Board (A1), via serial communications, through the ribbon cable connected from the Power Board (A2).

A GREEN communications LED on the Auxiliary I/O Board (A4) is located adjacent to terminal block (A4-TB2). This LED blinks to indicate active communication between the Aux I/O Board and the Main Board.

For component details of the Auxiliary I/O Board (A4), refer to standard drawing:

• JE5253-21 (Style-5054, up to 25Adc, w/options)
  

All relays on the Auxiliary I/O Board (A4) are ‘failsafe’. If communication is lost between the Main Control Board (A1) and the Auxiliary I/O Board (A4), the relays will switch to the alarm state.

For an expanded document detailing Wiring & Configuration of the Auxiliary I/O board, including possible combining of alarms in the field, refer to Service Instruction (JD5089-00).