General switching value input signal acquisition circuit

Abstract

The invention relates to a general switching value input signal acquisition circuit, and belongs to the technical field of signal acquisition. The property (high level or low level) of an input switching value level signal is detected through two triodes of different types respectively, and the two triodes are connected in series to a control loop of a photoelectric coupler. When the input of any type of switching value signal is detected, one triode is always in a cut-off state, and the control loop of the photoelectric coupler is switched off. Only when no switching value signal is input, the two triodes are switched on synchronously, and the control loop of the photoelectric coupler is switched on. Thus, general acquisition of the switching value signals is finished, and differentiation between the existence (high level or low level) and absence (suspending state) of the switching value signals can be finished.

Description

technical field [0001] The invention relates to the technical field of signal acquisition, in particular to a general-purpose acquisition circuit for switching input signals. Background technique [0002] The switching signal is widely used in the field of industrial control. The in-position signals of various mechanical equipment must be converted into switching electric signals for computer to collect. During the conversion process, the switching signal generally has two voltage states: a high-level signal that is the same as the positive voltage of the status power supply and a low-level signal that is the same as the negative voltage of the status power supply. During the acquisition process of the switching signal, in order to ensure the reliability and electrical safety of the signal acquisition, most of them need to be electrically isolated from the processor circuit, so the acquisition of the switching signal mostly needs to use a photocoupler to complete the electri...

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Problems solved by technology

[0006] use figure 1 When the method in the method collects the high-level signal switching value, because the circuit can only confirm whether the high-level signal is input in principle, it cannot distinguish between the low-level signal and the floating signal (without level input), and cannot detect the low-level signal. The level signal is collected; figure 2 When the method in the method collects the switching value, because the circuit can only confirm whether the low-level signal is input in principle, it cannot distinguish between the high-level signal and the floating signal (without level input), and cannot perform high-level signal detection. collection

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