Abstract: An electro-optical control system having a multi-key keypad, an alpha-numeric display, means for periodically generating a pulsed light beam, means for detecting a portion of the light beam to generate an analog signal, means for converting the analog signal to a digital signal and means for subtracting an ambient light level form the digital data to generate a difference signal. The difference signal is averaged and filtered to generate a digital signal level which is displayed on the alpha-numeric display. The electro-optical control system has two output switches which are activated when digital signal level is between programmed upper and lower limits for each output switch. The values of the upper and lower limits are programmable using the keypad. The upper and lower limits are displayed on the alpha-numeric display as they are generated.