Sensor/transmitter plug-and-play for process instrumentation

Abstract

A sensor assembly with a sensing element sends a sensor signal from the sensing element to attached process transmitter over sensor connection wires. The sensor assembly has memory circuitry for storing information related to the sensor assembly and interface circuitry that provides for digital communication of the stored information with the attached process transmitter. This digital communication is sent over the sensor connection wires.

1 . A sensor assembly for use with a process transmitter, the sensor assembly comprising:
 a sensing element;   sensor connection wires for connecting the sensing element to the process transmitter to provide a sensor signal from the sensing element to the process transmitter;   memory circuitry for storing information related to the sensor assembly; and   interface circuitry connected to the sensor connection wires to provide digital communication between the memory circuitry and the process transmitter.   
     
     
         2 . The sensor assembly of  claim 1 , wherein the sensing element is a temperature sensing element. 
     
     
         3 . The sensor assembly of  claim 1 , wherein the interface circuitry inductively couples the memory circuitry to the sensor connection wires. 
     
     
         4 . The sensor assembly of  claim 3 , wherein the interface circuitry includes a transformer. 
     
     
         5 . The sensor assembly of  claim 1 , wherein the interface circuitry capacitively couples the memory circuitry to the sensor connection wires. 
     
     
         6 . The sensor assembly of  claim 1 , wherein the information related to the sensor assembly further comprises configuration information. 
     
     
         7 . The sensor assembly of  claim 1 , wherein the digital communication is provided by a modulated carrier signal. 
     
     
         8 . The sensor assembly of  claim 7 , wherein the interface circuitry derives power for the memory circuitry from the modulated carrier signal received over the sensor connection wires. 
     
     
         9 . The sensor assembly of  claim 7 , wherein the interface circuitry includes an RFID tag. 
     
     
         10 . The sensor assembly of  claim 7 , wherein the interface circuitry includes modulator/demodulator circuitry. 
     
     
         11 . The sensor assembly of  claim 1 , wherein the sensor signal provided to the process transmitter from the sensing element is unamplified. 
     
     
         12 . A sensor assembly for use with a process transmitter, the sensor assembly comprising:
 a sensing element;   sensor connection wires for connecting the sensing element to the process transmitter to provide a sensor signal from the sensing element to the process transmitter during a measurement mode;   memory circuitry for storing information related to the sensor assembly; and   interface circuitry connected to the sensor connection wires to provide digital communication between the memory circuitry and the process transmitter during a communication mode.   
     
     
         13 . The sensor assembly of  claim 12 , wherein the sensing element is a temperature sensing element. 
     
     
         14 . The sensor assembly of  claim 12 , wherein the interface circuitry inductively couples the memory circuitry to the sensor connection wires. 
     
     
         15 . The sensor assembly of  claim 14 , wherein the interface circuitry includes a transformer. 
     
     
         16 . The sensor assembly of  claim 12 , wherein the interface circuitry capacitively couples the memory circuitry to the sensor connection wires. 
     
     
         17 . The sensor assembly of  claim 12 , wherein the information related to the sensor assembly further comprises configuration information. 
     
     
         18 . The sensor assembly of  claim 12 , wherein the digital communication is provided by a modulated carrier signal. 
     
     
         19 . The sensor assembly of  claim 18 , wherein the interface circuitry derives power for the memory circuitry from the modulated carrier signal received over the sensor connection wires. 
     
     
         20 . The sensor assembly of  claim 18 , wherein the memory circuitry includes an RFID tag. 
     
     
         21 . The sensor assembly of  claim 18 , wherein the interface circuitry includes modulator/demodulator circuitry. 
     
     
         22 . The sensor assembly of  claim 12 , wherein the sensor signal provided to the process transmitter from the sensing element is unamplified. 
     
     
         23 . A process transmitter for use with a sensor assembly, the process transmitter comprising:
 interface circuitry for connecting the process transmitter to sensor connection wires from a sensor assembly to receive a sensor signal from the sensor assembly;   memory circuitry for receiving information related to the sensor assembly; and   sensor communication circuitry connected to the interface circuitry to provide digital communication between the memory circuitry and the sensor assembly.   
     
     
         24 . The process transmitter of  claim 23 , wherein the sensor assembly is a temperature sensor assembly. 
     
     
         25 . The process transmitter of  claim 23 , wherein the information related to the sensor assembly further comprises configuration information. 
     
     
         26 . The process transmitter of  claim 23 , wherein the digital communication is provided by a modulated carrier signal. 
     
     
         27 . The process transmitter of  claim 26 , wherein the sensor communication circuitry includes an RFID reader circuit. 
     
     
         28 . The process transmitter of  claim 26 , wherein the sensor communication circuitry includes modulator/demodulator circuitry. 
     
     
         29 . The process transmitter of  claim 27 , wherein the sensor communication circuitry derives power from excess transmitter current. 
     
     
         30 . A process transmitter for use with a sensor assembly, the process transmitter comprising:
 interface circuitry for connecting the process transmitter to sensor connection wires from a sensor assembly to receive a sensor signal from the sensor assembly during a measurement mode;   memory circuitry for receiving information related to the sensor assembly; and   sensor communication circuitry connected to the interface circuitry to provide digital communication between the memory circuitry and the sensor assembly during a communication mode.   
     
     
         31 . The process transmitter of  claim 30 , wherein the sensor assembly is a temperature sensor assembly. 
     
     
         32 . The process transmitter of  claim 30 , wherein the information related to the sensor assembly further comprises configuration information. 
     
     
         33 . The process transmitter of  claim 30 , wherein the digital communication is provided by a modulated carrier signal. 
     
     
         34 . The process transmitter of  claim 33 , wherein the sensor communication circuitry includes an RFID reader circuit. 
     
     
         35 . The process transmitter of  claim 34 , wherein the sensor communication circuitry derives power from excess transmitter current 
     
     
         36 . The process transmitter of  claim 33 , wherein the sensor communication circuitry includes modulator/demodulator circuitry. 
     
     
         37 . The process transmitter of  claim 30 , wherein the sensor signal provided to the process transmitter from the sensor assembly is unamplified. 
     
     
         38 . A method of configuring a sensor assembly/process transmitter combination:
 connecting a sensor assembly to a process transmitter through sensor connection wires;   supplying a carrier signal from the process transmitter to the sensor assembly through the sensor connection wires powering memory circuitry associated with the sensor assembly with the carrier signal;   modulating the carrier signal based upon configuration data of the sensor assembly stored by the memory circuitry to produce a modulated carrier signal containing the configuration data;   demodulating the modulated carrier signal to obtain the configuration data; and   configuring the process transmitter based upon the configuration data.   
     
     
         39 . The method of  claim 38  and further comprising:
 modulating the carrier signal at the process transmitter to produce a modulated carrier signal containing data to be stored by the memory circuitry;   demodulating the modulated carrier signal containing data to be stored; and   writing the data to be stored into the memory circuitry.   
     
     
         40 . The method of  claim 38 , wherein the sensor assembly is a temperature sensor assembly. 
     
     
         41 . A sensor assembly/process transmitter comprising:
 a process transmitter, and   a sensor assembly comprising:
 a sensing element; 
 sensor connection wires for connecting the sensing element to the process transmitter to provide a sensor signal from the sensing element to the process transmitter; 
 sensor memory circuitry for storing information related to the sensor assembly; and 
 sensor interface circuitry connected to the sensor connection wires to provide digital communication between the sensor memory circuitry and the process transmitter; 
   wherein the process transmitter comprises:
 transmitter interface circuitry for connecting the process transmitter to sensor connection wires from a sensor assembly to receive a sensor signal from the sensor assembly; 
 transmitter memory circuitry for receiving information related to the sensor assembly; and 
 sensor communication circuitry connected to the interface circuitry to provide digital communication between the transmitter memory circuitry and the sensor assembly. 
   
     
     
         42 . The sensor assembly/process transmitter of  claim 41 , wherein the sensing element is a temperature sensing element. 
     
     
         43 . The sensor assembly/process transmitter of  claim 41 , wherein the sensor interface circuitry inductively couples the sensor memory circuitry to the sensor connection wires. 
     
     
         44 . The sensor assembly/process transmitter of  claim 43 , wherein the sensor interface circuitry includes a transformer. 
     
     
         45 . The sensor assembly/process transmitter of  claim 41 , wherein the sensor interface circuitry capacitively couples the sensor memory circuitry to the sensor connection wires. 
     
     
         46 . The sensor assembly/process transmitter of  claim 41 , wherein the information related to the sensor assembly further comprises configuration information. 
     
     
         47 . The sensor assembly/process transmitter of  claim 41 , wherein the digital communication is provided by a modulated carrier signal. 
     
     
         48 . The sensor assembly/process transmitter of  claim 47 , wherein the sensor interface circuitry derives power for the sensor memory circuitry from the modulated carrier signal received over the sensor connection wires. 
     
     
         49 . The sensor assembly/process transmitter of  claim 47 , wherein the sensor interface circuitry includes an RFID tag, and wherein the sensor communication circuitry includes an RFID reader circuit. 
     
     
         50 . The sensor assembly/process transmitter of  claim 47 , wherein the sensor interface circuitry includes modulator/demodulator circuitry. 
     
     
         51 . The sensor assembly/process transmitter of  claim 41 , wherein the sensor signal provided to the process transmitter from the sensing element is unamplified. 
     
     
         52 . The sensor assembly/process transmitter of  claim 47 , wherein the sensor communication circuitry includes modulator/demodulator circuitry. 
     
     
         53 . The sensor assembly/process transmitter of  claim 49 , wherein the sensor communication circuitry derives power from excess transmitter current.