Method for detecting faults on safety oriented sensors
AssigneeSiemens Aktiengesellschaft
InventorsHeiko Groenewold, Ronald Hauf
Life of this patent
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Abstract
A method for fault detection in the operation of sensors with at least two decoupled signal-transmitting elements with contacts and with a closed conductor loop includes delaying, a first test output by a defined switching delay with reespect to a second test output and evaluating the input channels in accordance with a defined expectation. Faults being inferred from deviations between actual and expected signal variations and time intervals.
Claims5
A method for detecting faults in the operation of sensors having two jointly actuable, contacted, electrically uncoupled signal-emitting elements each of which has a closed conductor loop, and is impressed on an input side via of a test output with a respective DC voltage signal which is passed on the output side to an associated input channel comprising, delaying each test output by a defined time interval relative to other test outputs so that the DC voltage occurs with a corresponding switch delay at a signal-emitting element and the input channels follow a defined sequence of signal changes having a fixed time assignment;
- and evaluating the input channels on the basis of the signal changes and time interval according to a defined expectation, whereby conclusions are drawn from deviation of actual and expected signal changes and/or time intervals relating to the presence of errors;
- said method being carried out in the framework of a positive dynamization and/or upon switching on and/or switching off of each sensor.
Dependencies are inferred from the claim text.