Status indicatorsRUNLEDSTOPLEDStatuson off The CPU is in the RUN state.off on The CPU is in the STOP state. After a stoprequest by switch or PG function, the STOPLED is continuously lit because the transitionto the STOP state was requested by the user or,in multiprocessor operation, by another CPU,and was not caused by the CPU itself.off off The CPU is in the INITIAL START orprogram check state.off slowflashingThe CPU is in the STOP state. The CPU hascaused a transition to the STOP state (possiblyalso for the other CPUs). If you set the modeswitch to STOP, the flashing LED becomescontinuously lit.off rapidflashingThe CPU is in the STOP state. An overall resethas been requested. This request can beinitiated by the CPU itself or by operatoraction.LEDs for fault indication andsignallingQVZ LEDon During direct access or process image update, a moduleaddressed by the program no longer acknowledgesalthough•• either it has acknowledged in single-processoroperation upon reset of the CPU 928B in the area ofthe process image (IB 0 to 127, QB 0 to 127) andhas been entered as present in the "9th track" (seeProgramming Guide, CPU 928B),•• or it has been entered in DB 1 (address list) inmultiprocessor or single-processor operation andhas been recognized as present during the reset.Possible causes•• Module failure.•• Module was pulled out during operation, in theSTOP state or in the Off state without a subsequentreset.CPU 928BSystem Manual5 - 28 C79000-B8576-C199-03
