Apparatus for Fault Tolerant Analog Inputs

An input termination board for use with an industrial controller in a safety system is disclosed herein. The industrial controller may be populated with standard analog input modules according to the requirements of the application. The termination board may selectively receive a single analog input signal from a remote device and transmit the signal to corresponding channels on two analog input modules or, alternately, receive two analog input signals and transmit each signal to one of the two corresponding channels. In addition, a program executing on the controller of the safety module monitors and tests each of the analog input channels on the input modules, verifying proper operation of the modules. If the program detects a fault in either input module, the safety system may alternately shut down according to a fail-safe procedure or continue operating under a fault-tolerant mode of operation.