Circuit that deciphers between AC and DC input signals

摘要

Aspects of the present invention provide a module including an electronic circuit that flags the presence of AC or DC input signals. An AC filter receives an input signal and couples it to a first leg. The AC filter permits an AC signal to pass to produce a first output and prevents a DC signal from passing. A DC filter also receives the input signal and couples it to a second leg. The DC filter permits a DC signal to pass to produce a second output and prevents at least part of an AC signal from passing. A lock out circuit in the first leg prevents the second leg from producing the second output when the first leg produces the first output. The output of each leg may be digitized and coupled to a logic controller to flag the presence of AC or DC input signals.

主权项

1. A module for use in an industrial control system, the module comprising:
an enclosure: an electrical terminal disposed on the enclosure for receiving an input signal; an electronic circuit coupled to the electrical terminal for deciphering between AC and DC input signals, wherein, in response to the input signal, the electronic circuit produces at least one of a first output for indicating the AC input signal and a second output for indicating the DC input signal; and a logic controller configured to process the first and second outputs for flagging the presence of the AC input signal in response to the first output and flagging the presence of the DC input signal in response to the second output.