An input/output (I/O) device for an automation control system includes a device housing containing control circuitry, the device housing being mountable to a support, a control power input for receiving control power from a first adjacent I/O device when connected thereto, the control power input configured to supply control power to the control circuitry, a control power output for outputting control power to a second associated adjacent I/O device, a field power input for receiving field power from the first associated adjacent I/O device when connected thereto, and a field power output for transmitting field power to the second associated I/O device. The field power input is selectively removable to prevent field power from being received by the I/O device from the first associated adjacent I/O device when connected thereto.