Use these boards when electrical isolation is needed, or when an interface is needed between circuits operating at different ground levels. These boards are also useful in environments with high electrical noise.
In a fiber optic installation, signals are not sent from one application to the other electrically (with wires). Rather, the signal is sent by transmitting light thru a thin, flexible, fiber optic cable. The transmitter board transmits the light based on its logic input (electrical), and the receiver board receives the light and generates a corresponding logic output (electrical). Relatively long distances can be achieved without concern for electromagnetic immunity or radiated emissions.