Method and Device for Monitoring a Device Equipped with a Microprocessor

• US 20120150492A1
• Filed: 12/06/2011
• Published: 06/14/2012
• Est. Priority Date: 12/14/2010
• Status: Active Grant

• Current Assignee: Schneider Electric Industries SAS (Schneider Electric SE)
• Original Assignee: Schneider Electric Industries SAS (Schneider Electric SE)
• Inventors: Gruffaz, Franck
• Granted Patent: US 9,343,894 B2
• Time in Patent Office: Days
• US Class Current: 702/186
• CPC Class Codes: G06F 11/27 Built-in tests
• CPC Class Codes: H02H 1/0007 concerning the detecting means in general G01R or other subclasses of G01; reed switches H01H71/2445
• CPC Class Codes: H02H 3/044 Checking correct functioning of protective arrangements, e.g. by simulating a fault for differential current circuit breakers H02H3/335
• CPC Class Codes: H02H 3/05 with means for increasing reliability, e.g. redundancy arrangements for logic circuits H03K19/003
• CPC Class Codes: H02H 3/0935 the timing being determined by numerical means
• CPC Class Codes: H02H 7/263 involving transmissions of measured values comparison of currents or voltages using pilot wires H02H3/30

Abstract

A monitoring method of a device equipped with a microprocessor, comprising the following steps:

• • performance of at least one computation in the microprocessor from input data;
  • performance of at least one logic operation by logic gates in an external monitoring device from the same input data;
  • comparison of the results of the at least one computation performed in the microprocessor and of the at least one logic operation performed in the monitoring device to deduce therefrom a diagnostic of the microprocessor and/or a command to switch to a safe configuration.

Claims

1. A monitoring method of a device equipped with a microprocessor, comprising the following steps:

performance of at least one computation in the microprocessor from input data;

performance of at least one logic operation by logic gates in an external monitoring device from the same input data;

comparison of the results of the at least one computation performed in the microprocessor and of the at least one logic operation performed in the monitoring device to deduce therefrom a diagnostic of the microprocessor and/or a command to switch to a safe configuration.

2. The monitoring method according to claim 1, further comprising the following steps:

determining at the level of the microprocessor the input data in the form of variable values corresponding to a certain number of predefined values;

transmission of these values to the monitoring device by communication means.

3. The monitoring method according to claim 2, wherein the step of determining the input data comprises random generation of the variable values and/or extraction and/or a combination of variable values from data bits coming from outside and received by the microprocessor.

4. The monitoring method according to claim 2, wherein the step of determining the input data comprises determination of the value of several numbers at least one bit of which is variable and takes a value equal to one of the variable values.

5. The monitoring method according to claim 4, wherein the step of performing at least one computation in the microprocessor comprises calculations such as divisions, multiplications, square roots, raising to the square, between the numbers.

6. The monitoring method according to claim 5, comprising a step of determining the least one bit representing the results of the at least one computation performed by the microprocessor, and a step of transmission of this at least one bit to the monitoring device.

7. The monitoring method according to claim 1, wherein the step of performing at least one computation in the microprocessor is performed by software of a diagnostic unit of the microprocessor.

8. The monitoring method according to claim 2, wherein performance of at least one logic operation in the monitoring device comprises operations on the variable values.

9. The monitoring method according to claim 8, comprising making a comparison of the variable values from least one XOR gate in the monitoring device so as to obtain results on a single bit dependent on the equality or the difference of the compared variable values.

10. The monitoring device according to claim 1, wherein the comparison step comprises generation of a boolean a first value of which represents a normal state of the device equipped with a microprocessor and a second value of which represents a malfunctioning state.

11. The monitoring device according to claim 1, comprising a step of actuating the device to place it in a safety configuration when its microprocessor is in a malfunctioning state.

14. A system comprising a microprocessor, comprising an external monitoring device according to claim 12, detected by at least one communication means with the microprocessor, the microprocessor comprising a diagnostic unit which performs at least one computation of the monitoring method according to claim 1.

15. The system according to the claim 14, wherein it is an electric circuit breaker, an electric installation monitoring system or a safety controller.

12. A monitoring device far a device equipped with a microprocessor, comprising at least one input to receive data from a microprocessor, a hardwired logic unit to perform logic operations on data coming from the microprocessor, a comparator unit to compare the result of a computation performed by a microprocessor with a result obtained by the hardwired logic unit, and an output to transmit the signal representing the result of the diagnostic of operation of the microprocessor.

13. The monitoring device according to claim 12, wherein its hardwired logic unit and its comparator unit comprise logic gates of OR, NOR, AND, NAND, XOR and/or XNOR type.