CA1145052A - Device for monitoring abnormality of sampled signals - Google Patents
Device for monitoring abnormality of sampled signalsInfo
- Publication number
- CA1145052A CA1145052A CA000372604A CA372604A CA1145052A CA 1145052 A CA1145052 A CA 1145052A CA 000372604 A CA000372604 A CA 000372604A CA 372604 A CA372604 A CA 372604A CA 1145052 A CA1145052 A CA 1145052A
- Authority
- CA
- Canada
- Prior art keywords
- signals
- abnormality
- sampled
- memory circuit
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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- Emergency Protection Circuit Devices (AREA)
Abstract
DEVICE FOR MONITORING ABNORMALITY OF
SAMPLED SIGNALS
ABSTRACT
The disclosed abnormality monitoring device comprises a monitored system wherein a current signal from an associated electric power system is sampled at predetermined constant time intervals and converted to digital signals, a memory circuit for storing three consecutive digital signals in it and a coincidence sensor circuit for investigating the identity of the three consecutive signals stored in the memory circuit.
SAMPLED SIGNALS
ABSTRACT
The disclosed abnormality monitoring device comprises a monitored system wherein a current signal from an associated electric power system is sampled at predetermined constant time intervals and converted to digital signals, a memory circuit for storing three consecutive digital signals in it and a coincidence sensor circuit for investigating the identity of the three consecutive signals stored in the memory circuit.
Description
DEVICE FOR MONITORING
ABNORMALITY OF SAMPLED SIGNALS
This invention relates to a device for monitoring the abnormality of sampled signals, and more particularly to such a device for detecting the abnormality of devices involved with signals sampled at predetermined constant time intervals from a periodic AC signal.
In digital data processing systems comprising a sampling circuit for sampling a periodic AC signal, for example, a current signal flowing through an electric power system at a predetermined constant time periods (which are normally equal to angular intervals of 30 degrees of an electrical angle of a current flowing through the electric power system), a conversion circuit for converting the sampled signals to corresponding digital si~nals, and a supply circuit for supplying the convarted digital signals to digital processing means involved, it is seen from the characteristics of the current signal that sampled data are of a constant periodicity and not identical in value to one another except for data located just before and after the peak point thereof. Therefore where three consecutive data are identical in value to one another, there is a chance that the abnormality may exist in any one or more of the sampling and conversion means and others.
The operation of digital data processing systems such as described above has been previously tested by switching the input thereto to the test side, introducing a known testing signal into the system and investigating an output S~352 from the system. This measure is to introduce the input into the tested system from the test side thereof and strictly speaking, it is different from the investigation of the state in which the tested system is actually operated.
Therefore the measure as described above has been disadvantageous in that the result of the test is low in reliability.
Accordingly it is an object of the present invention to provide a new and improved abnormality monitoring device capable of detecting errors in sampled data and also the abnormality occurring in an equipment including a sampling circuit and a digital conversion circuit.
The present invention provides a device for monitoring the abnormality of sampled signals comprising a memory circuit for storing therein _ consecutive data for signals sampled at predetermined constant time periods from a periodic AC signal and converted to digital forms, wherein _ is an integer having a value of not less than three, and a coincidence sensor circuit connected to the memory circuit to investigate the identity of the contents of the memory circuit.
The present invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawing in which a single Figure shows one embodiment of a device for monitoring the abnormality of sampled signals in accordance with the present invention.
In the arrangement illustrated, a monitored system 10 is applied with a periodic AC signal, in this case, a current signal lOa from an associated electric power system (not shown) and includes a sampling circuit for sampling the ~45~5~
current signal at predetermined constant time interval, in this case at equal angular intervals of 30 degrees of its time period, and a digital conversion circuit for converting the sampled signals to corresponding digital signals although both circuits are not illustrated only for purposes of illustration. The digital signals or data 10_ thus obtained are supplied to both an external digital device (not shown) and the abnormality monitoring device 12 of the present invention.
The abnormality monitoring device 12 includes a memory circuit 14 for storing therein n consecutive signals 10b where n is an integer having a value of not less than three (3), in the example illustrated, three consecutive signals 10a or three samples, and a concidence sensor circuit 16 connected to the memory circuit 14. The coincidence sensor circuit 16 investigates if data for three samples stored in the memory circuit 14 are identical in value to one another. If the three samples are identical in value to one another as determined thereby, then the coincidence sensor circuit 16 produces an output signal 16a having a value of binary ONE indicating the presence of the abnormality.
When the monitored system 10 is norrnally operated, the three consecutive signals 10_ are not identical in value to one another. Therefore the coincidence sensor circuit 16 produces the output signal having a value of binary ZERO.
However if the monitored system 10 is put in its abnormal state for some reasons so that three signal 10b with the same values are consecutive to one another then the contents of the memory circuit 14 become equal to one another which ~45~)52 is, in turn, sensed by the concidence sensor circuit 16. As a result, the sensor circuit 16 produces the output signal 16a having a value of binary ONE.
If the input signal 10a is of a null value then the abnormality monitoring device 12 is operated provided that it stands. In ord~r to prevent that operation, the abnormality monitoring device may includes a discrimination circuit (not shown) having entered thereinto the conditions for putting a disconnecting switch and a circuit breaker (not shown) coupled to the monitored system 10 into their closed or open position. Alternatively those conditions may be processed by separate means.
ABNORMALITY OF SAMPLED SIGNALS
This invention relates to a device for monitoring the abnormality of sampled signals, and more particularly to such a device for detecting the abnormality of devices involved with signals sampled at predetermined constant time intervals from a periodic AC signal.
In digital data processing systems comprising a sampling circuit for sampling a periodic AC signal, for example, a current signal flowing through an electric power system at a predetermined constant time periods (which are normally equal to angular intervals of 30 degrees of an electrical angle of a current flowing through the electric power system), a conversion circuit for converting the sampled signals to corresponding digital si~nals, and a supply circuit for supplying the convarted digital signals to digital processing means involved, it is seen from the characteristics of the current signal that sampled data are of a constant periodicity and not identical in value to one another except for data located just before and after the peak point thereof. Therefore where three consecutive data are identical in value to one another, there is a chance that the abnormality may exist in any one or more of the sampling and conversion means and others.
The operation of digital data processing systems such as described above has been previously tested by switching the input thereto to the test side, introducing a known testing signal into the system and investigating an output S~352 from the system. This measure is to introduce the input into the tested system from the test side thereof and strictly speaking, it is different from the investigation of the state in which the tested system is actually operated.
Therefore the measure as described above has been disadvantageous in that the result of the test is low in reliability.
Accordingly it is an object of the present invention to provide a new and improved abnormality monitoring device capable of detecting errors in sampled data and also the abnormality occurring in an equipment including a sampling circuit and a digital conversion circuit.
The present invention provides a device for monitoring the abnormality of sampled signals comprising a memory circuit for storing therein _ consecutive data for signals sampled at predetermined constant time periods from a periodic AC signal and converted to digital forms, wherein _ is an integer having a value of not less than three, and a coincidence sensor circuit connected to the memory circuit to investigate the identity of the contents of the memory circuit.
The present invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawing in which a single Figure shows one embodiment of a device for monitoring the abnormality of sampled signals in accordance with the present invention.
In the arrangement illustrated, a monitored system 10 is applied with a periodic AC signal, in this case, a current signal lOa from an associated electric power system (not shown) and includes a sampling circuit for sampling the ~45~5~
current signal at predetermined constant time interval, in this case at equal angular intervals of 30 degrees of its time period, and a digital conversion circuit for converting the sampled signals to corresponding digital signals although both circuits are not illustrated only for purposes of illustration. The digital signals or data 10_ thus obtained are supplied to both an external digital device (not shown) and the abnormality monitoring device 12 of the present invention.
The abnormality monitoring device 12 includes a memory circuit 14 for storing therein n consecutive signals 10b where n is an integer having a value of not less than three (3), in the example illustrated, three consecutive signals 10a or three samples, and a concidence sensor circuit 16 connected to the memory circuit 14. The coincidence sensor circuit 16 investigates if data for three samples stored in the memory circuit 14 are identical in value to one another. If the three samples are identical in value to one another as determined thereby, then the coincidence sensor circuit 16 produces an output signal 16a having a value of binary ONE indicating the presence of the abnormality.
When the monitored system 10 is norrnally operated, the three consecutive signals 10_ are not identical in value to one another. Therefore the coincidence sensor circuit 16 produces the output signal having a value of binary ZERO.
However if the monitored system 10 is put in its abnormal state for some reasons so that three signal 10b with the same values are consecutive to one another then the contents of the memory circuit 14 become equal to one another which ~45~)52 is, in turn, sensed by the concidence sensor circuit 16. As a result, the sensor circuit 16 produces the output signal 16a having a value of binary ONE.
If the input signal 10a is of a null value then the abnormality monitoring device 12 is operated provided that it stands. In ord~r to prevent that operation, the abnormality monitoring device may includes a discrimination circuit (not shown) having entered thereinto the conditions for putting a disconnecting switch and a circuit breaker (not shown) coupled to the monitored system 10 into their closed or open position. Alternatively those conditions may be processed by separate means.
Claims
THE EMBODIMENT OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED IS DEFINED AS FOLLOWS:
A device for monitoring the abnormality of sampled signals comprising a memory circuit for storing n consecutive data for signals sampled at predetermined constant time periods from a periodic AC signal and converted to digital forms where n is an integer having a value of not less than three, and a concidence sensor circuit connected to said memory circuit to investigate the identity of the contents of said memory circuit.
PROPERTY OR PRIVILEGE IS CLAIMED IS DEFINED AS FOLLOWS:
A device for monitoring the abnormality of sampled signals comprising a memory circuit for storing n consecutive data for signals sampled at predetermined constant time periods from a periodic AC signal and converted to digital forms where n is an integer having a value of not less than three, and a concidence sensor circuit connected to said memory circuit to investigate the identity of the contents of said memory circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000372604A CA1145052A (en) | 1981-03-09 | 1981-03-09 | Device for monitoring abnormality of sampled signals |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000372604A CA1145052A (en) | 1981-03-09 | 1981-03-09 | Device for monitoring abnormality of sampled signals |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1145052A true CA1145052A (en) | 1983-04-19 |
Family
ID=4119408
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000372604A Expired CA1145052A (en) | 1981-03-09 | 1981-03-09 | Device for monitoring abnormality of sampled signals |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1145052A (en) |
-
1981
- 1981-03-09 CA CA000372604A patent/CA1145052A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |