6F8C1048 856.2Dual Line System6(4) S3 down or downgrade to standbyIf the S is judged irrecoverable by its own diagnostic function, the S3 forces itself down.The AN712 detects it with the healthy counter and S3 operation monitor function, andstops scan transmission.When the S is downgraded to standby status, it is also detected by the S3 operationmonitor function and scan transmission is stopped.6.2.2 Standby operation(1) InitializingWhen initial start sets the system in standby status, no operation is needed by the S3application. As the switch AO is set to the ON position, the system is automaticallyengaged in the ADMAP transmission lines and operates online.(2) Upgrading to onlineThe application operation concerning the AN712 module upgraded from standby toonline operation is the same as the initializing operation shown in figure 6-2. However, itis not necessary to issue an inring request or an online request because the switch AO isset to the ON position.