US 11,716,178 B2
Safety rated input module for an industrial controller
Daniel M. Alley, Earlysville, VA (US); John R. O'Connell, Painesville, OH (US); and Jared Bell, Lakewood, OH (US)
Assigned to Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US)
Filed by Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US)
Filed on Oct. 21, 2022, as Appl. No. 17/970,929.
Application 17/970,929 is a continuation of application No. 17/005,983, filed on Aug. 28, 2020, granted, now 11,496,254.
Prior Publication US 2023/0039029 A1, Feb. 9, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H04L 1/24 (2006.01); G05B 9/03 (2006.01); G05B 19/05 (2006.01); H04L 1/22 (2006.01)
CPC H04L 1/24 (2013.01) [G05B 9/03 (2013.01); G05B 19/058 (2013.01); H04L 1/22 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A safety-rated input module, comprising:
at least one input terminal to receive an input signal;
a first filter connected to the at least one input terminal to receive the input signal as an input to the first filter;
a second filter connected to the at least one input terminal to receive the input signal as an input to the second filter, wherein the first filter and the second filter are connected in parallel; and
a processor operative to:
receive a first filtered input signal from the first filter,
receive a second filtered input signal from the second filter,
generate a test signal at a predefined frequency,
inject the test signal into the first filter,
determine a first frequency response of the first filter as a function of the test signal,
inject the test signal into the second filter,
determine a second frequency response of the second filter as a function of the test signal, and
identify a failure in either the first filter or the second filter as a function of the first frequency response and of the second frequency response.