A system for monitoring and controlling the safety system of equipment, which is used to insure personnel safety and cause the system to "fail safe" in the event of computer or software failure, the failure of a critical piece of hardware, or the opening of any interlock indicating, for example, the unexpected entry of personnel into a dangerous area. Provides an integrated system of timed status monitoring hardware and software for use in a distributed-network computer-controlled environment. The hardware piece of this system includes a digital I/O computer add-on card, or other hardware supporting high-speed alternating state telemetry, and a custom circuit card. Such a circuit, when used within the overall control system can monitor the state of interlock switches and monitor the status of the computer control system(s). Such a safety circuit can then cause a shutdown appropriate to the failure detected. In addition, it has an ability to sense local hardware status information and immediately signal the computer of any potentially dangerous situation.