| The significance of machine monitoring equipment in the framework of a protective function relies on high availability, reliability and interruption-free operation. All monitoring modules possess the identical system security concept. Watch dog
Continuous checking of the signal processing with the configuration saved in the EEPROM. If differences are identified the measured values and status of all relays are frozen, the working memory is re-loaded and a signal is despatched to energize the central OK relay. Power failure
Short-term power failures are recognized and signalled as an OK fault. Energy stored in the power supply is used to power the monitoring modules for up to 250 ms without interruption. Power-return protection
During initial power-up, measuring chains surging, loading of the working memory and during the first 5 measuring cycles, no signal assessment is done. During this time the analogue outputs and status of all relays are frozen to prevent false alarms. OK–fault
Here the OK window is permanently monitored. Any interruptions in the measurement chain and input amplifiers are recognized and signalled. | 
