5.13.2 Function securityThe CPUs include security mechanisms like a Watchdog (100ms) and a parameterizablecycle time surveillance (parameterizable min. 1ms) that stop res. execute a RESET at theCPU in case of an error and set it into a defined STOP state. The VIPA CPUs are devel-oped function secure and have the following system properties:Event concerns EffectRUN ® STOP general BASP (Befehls-Ausgabe-Sperre, i.e. command outputlock) is set.central digital outputs The outputs are disabled.central analog outputs The outputs are disabled.n Voltage outputs issue 0Vn Current outputs 0...20mA issue 0mAn Current outputs 4...20mA issue 4mAIf configured also substitute values may be issued.decentral outputs Same behavior as the central digital/analog outputs.decentral inputs The inputs are cyclically be read by the decentralizedstation and the recent values are put at disposal.STOP ® RUN res. PowerON general First the PII is deleted, then OB 100 is called. Afterthe execution of the OB, the BASP is reset and thecycle starts with: Delete PIO ® Read PII ® OB 1.decentral inputs The inputs are once be read by the decentralized sta-tion and the recent values are put at disposal.RUN general The program execution happens cyclically and cantherefore be foreseen: Read PII ® OB 1 ® WritePIO.PII: Process image inputs, PIO: Process image outputsVIPA System 300S+Deployment CPU 317-4PN23Operating modes > Function securityHB140 | CPU | 317-4PN23 | en | 18-0172
