Detection of inductive communication for programmable logic controller diagnosis

摘要

Inductive commutation is detected for programmable logic controller (PLC) diagnosis. By detecting the inductive commutation, the need for any delay may be determined. Where the load is not inductive, the diagnostic may be performed with little or no delay.

主权项

1. A system for detection of inductive commutation for programmable logic controller (PLC) diagnosis, the system comprising:
an output driver connected with an output of the PLC; a diagnostic detection circuit connectable or connected with the output; an inductive commutation detection circuit connected with the output, the inductive commutation detection circuit operable to detect the inductive commutation in response to the output driver turning off, wherein the inductive commutation is a negative voltage having greater than a threshold amplitude; and a processor configured to delay reading of the diagnostic detection circuit in response to the detection of the inductive commutation and to initiate the reading of the diagnostic detection circuit when the inductive commutation detection circuit detects no inductive commutation.