| 摘要 |
The aim of the invention is to provide a digital input module (1) for a data-processing system. With said input module it is possible to obtain a digital signal from a binary-coded signal alternating voltage or signal direct voltage applied to a contact (5) of a signal transmitter (10). There are also means for monitoring the mode of functioning of the digital input module. According to the invention, a digital input module (1) for a data-processing system, for obtaining a digital signal from a binary-coded signal voltage applied to a contact (5) of a signal transmitter (10) has an input unit (15) which can be connected to the contact (5) and to the data-processing system, a changeover unit (30) which is connected to said input unit (15) and which subjects the input unit (15) to a tap voltage of zero volts in order to obtain the digital signal and subjects the input unit (15) to a test voltage in order to produce a test signal; and an optocoupler (20) which is located in the input unit (15). Said optocoupler is connected to the two inputs of the input unit (E15a, E15b) and to the output (A15a) of the input unit (15) by a rectifier bridge (25). |
