13.1.2-1 Local Indication of Redundant Equipment Status

If equipment can automatically transfer operation between redundant units, local personnel who maintain that equipment should be informed of the transfer and the status of the redundant units.

Additional Information:
Some digital systems automatically transfer control between redundant processors when there is a failure. These redundant processors support on-line maintenance by allowing one processor to control the system while the others are being serviced. When maintenance is performed, local maintenance personnel should be alerted when an automatic transfer occurs, and should be able to readily determine the status of the redundant processors and identify the one controlling the system. Local indications are preferable to control room indications so local personnel need not rely on workers for status information.