Safety monitoring and control system

Claims

1. A closed loop safety monitoring and control system comprising:

a switching device;

a sensor coupled to the switching device for sensing a predetermined condition thereof and for providing sensor output signals indicative of the predetermined condition;

a programmable controller comprising a seismic sensor for detecting a seismic disturbance and providing seismic output signals indicative of the seismic disturbance, wherein the controller is coupled between the sensor and the switching device and forms a closed loop control system for monitoring and controlling the switching device, and wherein the controller is responsive to the sensor output signals and the seismic output signals, and provides first control signals that are applied to the switching device in the absence of a seismic disturbance to provide for closed loop control of the switching device under normal operating conditions, and provides second control signals that are applied to the switching device in the presence of a seismic disturbance to provide for closed loop control of the switching device under emergency operating conditions.

2. The closed loop safety monitoring and control system of claim 1 wherein the seismic sensor comprises a signal output that is directly coupled to the switching device for actuating the switching device to place it in a predetermined condition in the event of failure of the programmable controller.