What is an Digital Input Signal?

Digital input signal refers to a contact output signal generated and transmitted from local equipment.

For example, answer-back signal to express equipment conditions, alarm signal for abnormal conditions and “remote / local” switch signal of local control panels are examples of digital input signal.

Contact signals are electronically converted to an appropriate series of zeros and ones. Link systems with PLC are widely used for transmitting the signal, with which analog signal is converted to digital signal and is transmitted via coaxial cables or optical fibres.