The Vital Interlink is a timed power supply with an isolated twelve volt output. Its design is focused on fail-safe principles and implements critical redundancies necessary for a truly vital system.
The device features two on-board microcontrollers (MCUs) to independently monitor and interpret all user and diagnostic input data. The MCUs are able to detect discrepancies and alert the user prior to enabling an output through the exchange of independent interpretations.
Additionally, each MCU is provided with two control mechanisms that must be simultaneously set to enable the vital output. One mechanism is a high-reliability relay that breaks the circuit between the input and output terminals, the other is a logic circuit that disables the output power supply until both MCUs activate their control mechanisms.
In short, the redundancy in the design input monitoring, data processing, controls, and a hardware-based locking mechanism are to ensure that the failure of any individual component or circuit will result in a reliably deactivated output.