Measuring sensor device

• US 5,355,129 A
• Filed: 03/24/1993
• Issued: 10/11/1994
• Est. Priority Date: 08/01/1990
• Status: Expired due to Fees

• Current Assignee: Dr Ing hc F Porsche AG (Volkswagen AG)
• Original Assignee: Dr Ing hc F Porsche AG (Volkswagen AG)
• Inventors: Baumann, Bernd
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): Solis, Jose M.
• Application Number:
  US07/966,185
• Time in Patent Office: 566 Days
• Field of Search: 340/870.01, 340/870.02, 340/870.04, 340/870.11, 340/870.13, 340/870.14, 340/870.19, 324/601
• US Class Current: 340/870.04
• CPC Class Codes: G01D 18/006 Intermittent recalibration
• CPC Class Codes: G01D 18/008 with calibration coefficients stored in memory
• CPC Class Codes: G01D 3/022 having an ideal characteristic, map or correction data stored in a digital memory
• CPC Class Codes: G01R 17/10 AC or DC measuring bridges
• CPC Class Codes: G01R 35/005 Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references G01R33/0035, G01R35/002 take precedence

Abstract

A measuring sensor device for the detection of physical quantities is equipped with an identification generator in whose memory module correction data (sensor identification data) are stored. For the transmission of identification data, the identification generator is connected, via two of the lines which are normally used for the measured value transmission and/or the energy supply of the measuring sensor device and another line used for a shunt calibration of the measuring sensor device, to the analysis circuit and can be activated and controlled by the latter. By means of a special wiring of the identification generator, correction data may also be fed into it during a calibration. The thus obtained system for the detection of physical quantities is therefore distinguished by high flexibility, simplicity with respect to circuits and operatability in extreme temperatures.

Claims

1. An arrangement comprising:

a measuring sensor device for detecting a physical quantity with a physical electrical transducer that converts the physical quantity into an equivalent analog electrical quantity, the physical-electrical transducer being connected in a bridge circuit with branches;

an analysis circuit connected to the measuring sensor device, the analysis circuit being constructionally separate from the measuring sensor device and converting the analog electrical quantity into digital data;

electrical lines capable of transmitting measured values and supplying energy to the measuring sensor device;

a shunt resistor on the measuring sensor device, shunt switches connected to the analysis circuit, and a shunt line connecting the shunt switches with the shunt resistor (shunt calibration, calibrating operation), the individual branches of the measuring bridge, for calibration purposes, being capable of being detuned in a defined manner by the shunt resistor, the shunt switches and the shunt line;

an identification generator integrated in the measuring sensor device and having a nonvolatile memory module with correction data (sensor identification data) of the measuring sensor device, a controllable switching element situated in parallel to one of the branches of the measuring bridge, for the defined detuning of the measuring bridge in the controlled condition;

the identification generator including at least one auxiliary shunt resistor and at least one electrically controllable auxiliary shunt switch the auxiliary shunt resistor being connectable in parallel by the auxiliary shunt switch to the shunt switches and the shunt resistor;

the identification generator further including a controlling circuit which responds to defined pulses on the shunt line and controls the identification generator, such that the identification generator has operating modes (measuring operation, calibrating operation) that are switchable in response to superimposition of said pulses on the shunt line by means of the shunt switches, the operating modes including;

measuring operation and calibrating operation, the identification generator being switched such that measuring sensing is substantially unaffected by the identification generator,

calibrating operation, the physical-electrical transducer being detuned in a defined manner by the shunt switches and the shunt resistor,

identifying operation, by controlling the auxiliary shunt switches via the controlling circuit, with correction data being transmitted via the measuring lines from the identification generator to the analysis circuit.

2. A measuring sensor device according to claim 1, wherein the controlling circuit has at least one counting circuit which detects at least one of the pulse length, the pulse number of the pulses and a pulse sequence on the shunt line and, switches the operating mode as a function thereof and, in the operating mode identifying operation, initializes and controls the transmission of correction data.

3. A measuring sensor device according to claim 2, wherein the controlling circuit of the identification generator includes means for controlling and addressing the memory module, and means for editing and converting control commands, data and addresses from and to the memory module.

4. A measuring sensor device according to claim 2, wherein control information, addresses and data are transmittable from the analysis circuit to the identification generator for the readin of sensor identification data via the shunt line.

5. A measuring sensor device according claim 1, wherein the first shunt switch activates the transmission of the identification data to the analysis circuit (initiating of the identifying operation, initializing of the identification generator) by superimposing a certain first number of pulses of a defined first pulse width on the shunt line.

6. A measuring sensor device according to claim 5, wherein the transmission parameters for the transmission of the identification data are determined by superimposing a certain second number of pulses of a defined first pulse width on the shunt line by means of the first shunt switch.

7. A measuring sensor device according to claim 5, wherein a starting address of the identification data for their transmission is determined by superimposing a certain third number of pulses of a defined first pulse width on the shunt line by means of the first shunt switch.

8. A measuring sensor device according to claim 1, by superimposing a certain fourth number of pulses of a defined first pulse width on the shunt line via the first shunt switch, the identification generator is changed to a direct-access operating state in which data are readable in directly on certain memory location addresses of the memory module via the shunt line and are readable out from arbitrary memory location addresses of the memory module via the measuring lines.

9. A measuring sensor device according to claim 8, wherein readin/readout of data in the direct-access operating state is caused by superimposing a three-level signal on the shunt line, the three-level signal being generated by the first and second shunt switch, the controlling circuit of the identification generator converting the three-level signal into corresponding control signals for the identification generator, a bit-serial input of control commands, addresses and data (readin) / control, commands and addresses (readout) taking place via the second shunt switch, and a timing signal generated by means of the first shunt switch being synchronously superimposed on the control address and data signals.

10. A measuring sensor device according to claim 9, wherein the generating of the three-level signal takes place in such a manner that edges of the timing signal are shifted with respect to time to edges of the control, address or data signal.

11. A measuring sensor device according to claim 1, wherein the superimposing of a pulse of a defined second pulse width on the shunt line via the first shunt switch causes a termination of the transmission of the identification data or an activating of the shunt calibration.

12. A measuring sensor device according to claim 1, wherein the transmission of identification data from the identification generator to the analysis circuit takes place in an asynchronous data format, and wherein the controlling circuit of the identification generator, via one of the second and first auxiliary shunt switches outputs the bit-serial output of the data and synchronously superimposes a timing signal on the data signal by means of the one of the first and second auxiliary shunt switches.

13. A measuring sensor device according to claim 11, wherein the transmission of the identification data from the identification generator to the analysis circuit is performed via the measuring lines in an asynchronous data format by means of a three-level signal, for the generating of which the inverted signal of an OR-gate acted upon by the control, address or data flows and timing signal flows between the memory module and the controlling circuit controls the first auxiliary shunt switch, the inverted signal of a NOT-AND gate, which is acted upon by the same signal flows, controls the second auxiliary shunt switch.

14. A measuring sensor device according to claim 1, wherein localizing and switching of transmission parameters takes place via one of a hardwired logic and coding switches.

15. A measuring sensor device according to claim 1, wherein the measuring sensor device is switched by one of hardwired logic or coding switches from a shunt calibration via the shunt switches and the shunt resistor to the shunt calibration via the auxiliary shunt switches and the auxiliary shunt resistors.

16. A measuring sensor device according to claim 1, wherein one of the first and second pulse width of the pulses to be superimposed on the shunt line can be changed by one of hardwired logic and coding switches.

17. A measuring sensor device according to claim 1, wherein the sensor identification data, in addition to the correction data for the compensation of static and dynamic transducing characteristics of the measuring sensor device and parts of the analysis circuit, comprise additional operating data for the measuring sensor device or for the physical-electrical transducer, as well as data concerning the application site of the measuring sensor device.

18. A measuring sensor device according to claim 1, wherein the identification generator has a plurality of modules, and wherein the modules of the identification generator with a lower energy consumption are connected directly and modules with a higher energy consumption are connected via a stand-by circuit to an energy supply of the physical-electrical transducer.

19. A measuring sensor device according to claim 1, wherein the electrically controlled switches with respect to the parts of the sensor and of the physical-electrical transducer that are bridgeable are switching elements that are highly resistive and substantially capacitance-free in an uncontrolled state.

20. A measuring sensor device according to claim 19, wherein the switching elements are transistors.

21. A measuring sensor device according to claim 20, wherein the switching elements are field effect transistors.

22. A measuring sensor device according to claim 19, wherein the switching elements are analog switches.

23. A measuring sensor device according claim 1, wherein the memory module is an erasable and programmable nonvolatile memory module with a serial input/output.

24. The arrangement of claim 1, wherein the identification generator, in response to an activatable transmission of the correction data to the analysis circuit, switches the controllable switching element on and off in a frequency of the data bit flow read out serially from the memory module and the analysis circuit detecting the analog signals at the measuring bridge and regenerating the correction data from the analog signals, the correction data being useable for correction of the electrical quantities furnished by the physical-electrical transducer.