Diagnostic fault test system and circuit
First Claim
1. A multiple diagnostic fault test system comprising:
- a plurality of electrical devices, each device selectively operative in effective on or off states in accordance with received control signals to control load apparatus associated with each of said devices;
control means coupled to said plurality of devices for providing said control signals thereto in accordance with predetermined criteria to achieve desired control of said devices;
means for testing each of said devices to insure proper operation of said devices and/or its associated load apparatus controlled thereby, said testing means including,means for temporarily altering the control signal being provided to at least some of said devices such that each of said devices is maintained in a same predetermined one of said on and off states for a predetermined first time period,means for monitoring each of said plurality of devices during said first time period for proper operation and developing a fault signal in response to detected improper operation, andmeans for having said control means resume control of said devices after said first time period in accordance with said predetermined criteria.
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Accused Products
Abstract
Diagnostic fault test system and circuit sequentially tests a plurality of drivers (12) and their associated solenoid loads (13). Control signals (PM, SM) are provided to the drivers by a computer controller (11) to achieve desired solenoid actuation. The controller temporarily alters the control signals such that all of the drivers are forced into an on or off state for a first time period (tA or tB). After a delay (tDon or tDoff) a signal (VM) associated with each driver stage is monitored to determine if the driver and its load are operating properly. Then the controller resumes normal control of the drivers. The duration of the forced on/off state is short enough so as not to cause a change in the actuated/nonactuated state of the solenoid loads. Each monitored signal from the driver is sequentially compared to a high and low threshold (50, 51) to indicate either proper operation or the identification of one of two different types of fault which may occur. Drivers are preferably tested in both on and off states for proper operation and identification of a total of four different possible faults. Present system allows rapid testing of all drivers and their loads by use of a common transient setting delay time. Accuracy is improved since driver switching during fault monitoring is not permitted. Fewer components are needed since a single comparator (18) is used to sequentially compare each monitored signal for each driver with both high and low thresholds. Also, an indication of what type of fault is provided rather than just providing an indication that some fault exists.
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Citations
31 Claims
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1. A multiple diagnostic fault test system comprising:
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a plurality of electrical devices, each device selectively operative in effective on or off states in accordance with received control signals to control load apparatus associated with each of said devices; control means coupled to said plurality of devices for providing said control signals thereto in accordance with predetermined criteria to achieve desired control of said devices; means for testing each of said devices to insure proper operation of said devices and/or its associated load apparatus controlled thereby, said testing means including, means for temporarily altering the control signal being provided to at least some of said devices such that each of said devices is maintained in a same predetermined one of said on and off states for a predetermined first time period, means for monitoring each of said plurality of devices during said first time period for proper operation and developing a fault signal in response to detected improper operation, and means for having said control means resume control of said devices after said first time period in accordance with said predetermined criteria. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A device diagnostic fault test circuit comprising:
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at least one electrical device selectively operative in effective on or off states in accordance with received control signals to control load apparatus associated with said device; control means coupled to said device for providing said control signals to said device in accordance with predetermined criteria to achieve desired control of said device; means coupled to said device for testing said device for faulty operation of said device and/or its associated load apparatus controlled thereby; said testing means including, means coupled to said device for monitoring, during a predetermined first time period while said device is in a predetermined one of said on and off states, at least one signal from said device and comparing the magnitude of said monitored signal with both first and second threshold values, said first and second threshold values being distinct from each other, said testing means providing a first fault signal if said monitored signal exceeds said first threshold value in a first predetermined polarity sense and providing a second fault signal if said monitored signal exceeds said second threshold value in a predetermined polarity sense, the providing of just said first fault signal being indicative of a first type of faulty operation while the providing of both of said first and second fault signals being indicative of a second different type of faulty operation. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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Specification