Measurement Transducer having a Monitoring Function

• US 20170010597A1
• Filed: 11/17/2014
• Published: 01/12/2017
• Est. Priority Date: 12/23/2013
• Status: Active Grant

• Current Assignee: Endress+Hauser SE+Co. KG (Endress+Hauser AG)
• Original Assignee: Endress + Hauser GmbH + Company KG (Endress+Hauser AG)
• Inventors: Sautermeister, Manuel, Girardey, Romuald, Stib, Ralph, Karweck, Lars, Spitz, Andreas, Zieringer, Thomas
• Granted Patent: US 10,606,228 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01D 18/00 Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: G01D 2218/10 Testing of sensors or measuring arrangements
• CPC Class Codes: G01D 5/14 influencing the magnitude of a current or voltage
• CPC Class Codes: G01R 31/2829 Testing of circuits in sensor or actuator systems testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844
• CPC Class Codes: G01R 35/00 Testing or calibrating of apparatus covered by the other groups of this subclass
• CPC Class Codes: G05B 19/0425 Safety, monitoring
• CPC Class Codes: G05B 2219/24015 Monitoring
• CPC Class Codes: G05B 2219/25428 Field device
• CPC Class Codes: G05B 2219/33331 Test, diagnostic of field device for correct device, correct parameters
• CPC Class Codes: G05B 23/0235 based on a comparison with predetermined threshold or range, e.g. "classical methods", carried out during normal operation; threshold adaptation or choice; when or how to compare with the threshold
• CPC Class Codes: G05B 23/0237 based on parallel systems, e.g. comparing signals produced at the same time by same type systems and detect faulty ones by noticing differences among their responses
• CPC Class Codes: H04B 17/17 Detection of non-compliance or faulty performance, e.g. response deviations H04B17/18 takes precedence

Abstract

The invention relates to a measurement transducer (1) comprising a sensor module (10), having a sensor (11) and sensor electronics (12), wherein the sensor (11) emits sensor signals, and wherein the sensor electronics processes the digitized sensor signals with a transmission function and provides processed sensor measurement values on a digital interface. The measurement transducer further comprises a main electronics module (20), which is functionally connected to the sensor electronics and a logic unit (22), and a communications interface (36), wherein the logic unit (22) is configured to receive the sensor measurement values provided on the digital interface and to cause the output of a measurement signal corresponding to the sensor measurement values through the communications interface (36). To this end, the logic unit is configured to carry out a monitoring function—wherein the monitoring comprises, in addition to a currently provided sensor measurement value, the reception of the associated digitized sensor signals, with the aid of a test function which comprises the transmission function—to calculate a control measurement value with the aid of the received associated digitized sensor signals, to carry out a comparison between the control measurement value and the sensor measurement value, and to cause the communications interface to emit an error signal in the event of deviations. The logic unit is also configured to provide the control measurement value to the sensor electronics (12), wherein the sensor electronics (12) are configured to carry out a comparison between the control measurement value and the sensor measurement value and to cause the communications interface (36), via an alarm output (18), to directly emit an error signal in the event of deviations.

Claims

1. Measurement transducer (1), comprising:

a sensor module (10) having at least one sensor (11) and one sensor electronics (12), wherein the sensor (11) emits sensor signals, and wherein the sensor electronics processes the digitized sensor signals with a transmission function and provides processed sensor measurement values on a digital interface; and

a main electronic module (20), which is functionally connected to the sensor electronics unit, wherein the main electronic module has a logic unit (22) and a communications interface (36), wherein the logic unit (22) is configured to receive the sensor measurement values provided on the digital interface and to cause the output of a measurement signal corresponding to the sensor measurement values through the communications interface (36), wherein the logic unit is configured to carry out a monitoring function—

wherein the monitoring function comprises, in addition to a currently provided sensor measurement value, the reception of the associated digitized sensor signals, with the aid of a test function, which comprises the transmission function—

to calculate a control measurement value with the aid of the received associated digitized sensor signals, to carry out a comparison between the control measurement value and the sensor measurement value, and to cause the communications interface to emit an error signal in the event of deviations, wherein the logic unit is further configured to provide the control measurement value of the sensor electronics (12), wherein the sensor electronics (12) is configured to carry out a comparison between the control measurement value and the sensor measurement value and to cause the communications interface (36), via an alarm output (18), to directly emit an error signal in the event of deviations.

2. A measurement transducer according to claim 1, wherein the transmission function comprises an algorithm which is configured to compensate for sensor cross-sensitivity to disturbance variables and/or provide a linear sensor measurement value function.

3. A measurement transducer according to claim 1, wherein the test function comprises a testing algorithm which, in addition to an implementation of the transmission function, comprises additional steps, wherein the testing algorithm comprises an inverse step for each additional step, to the effect that, as a result, with proper execution of the testing algorithm and proper functioning of the microprocessor, the control measurement value is not modified by the additional steps.

4. A measurement transducer according to claim 3, wherein the further steps comprise arithmetic operations, each of them in combination with an operation inverse to it.

5. A measurement transducer according to claim 3, wherein the further steps comprise references or branching out of the algorithm of the transmission function and back.

6. A measurement transducer according to claim 1, wherein the sensor electronics are configured to provide the sensor measurement values with a defined output rate on the digital interface, wherein the logic unit is configured to monitor whether the output rates are met, and, if this is not the case, cause the communications interface to emit an error signal.

7. A measurement transducer according to claim 1, wherein the monitoring function is carried out in defined temporal intervals, wherein the execution of the monitoring function is initiated by the logic unit, wherein the sensor electronics monitors whether or not the time lag for initiating the monitoring function is satisfied.

8. A measurement transducer according to claim 1, wherein the logic unit is configured to provide the control measurement value within a predetermined processing time after reception of the digitized sensor signals, wherein the sensor electronics is configured to monitor whether or not the predetermined processing time is satisfied.

9. A measurement transducer according to claim 1, wherein the sensor electronics is configured to directly cause the communications interface to emit an error signal if a period of time to be monitored by the sensor electronics and to be satisfied by the logic unit is not satisfied.

10. A measurement transducer according to claim 1, wherein the sensor electronics is configured to read the control measurement value provided by the logic unit from a register and to write an error value, which is outside the domain of all possible control measurement values, to the register after readout of the control measurement value from the register, wherein, when functioning properly, the logic unit is configured to overwrite the error value with the subsequent control measurement value before the sensor electronics reads out the register the next time.

11. A measurement transducer according to claim 10, wherein the sensor electronics is configured to write the digitized sensor signals, which form the basis for the calculation of sensor measurement values, as error value to the register, in order to provide to the logic unit the digitized signals to determine the control measurement value, wherein, when functioning properly, the logic unit is configured to overwrite the digitized sensor signals, which, at the same time, serve as error value, with the next control measurement value, which was determined based upon the digitized sensor signals.