Contactless data carrier, interrogator, contactless data carrier system, and method of acquiring data

A method of acquiring data from a contactless data carrier connected to a signal source that generates an external signal according to an ambient physical quantity, the contactless data carrier including a measurement port for receiving the external signal, a variable threshold generator for generating different threshold values, a comparator for comparing the external signal received at the measurement port with the different threshold values and producing comparison results, and a controller for controlling the variable threshold generator according to commands received from the interrogator and returning the comparison results to the interrogator, the interrogator exchanging data with the contactless data carrier by wireless communication, the method comprising:

• sending, from the interrogator, the controller in the contactless data carrier a command to have the comparator execute repeated comparisons with different threshold values;
• sending, from the interrogator, the different threshold values to the contactless data carrier;
• receiving, by means of the interrogator, each of the comparison results from the contactless data carrier;
• and
• obtaining, by means of the interrogator, information about the ambient physical quantity by finding a boundary value at which the comparison results change.

A machine-readable medium storing code executable by a computing device for acquiring data from the contactless data carrier of that exchanges data by wireless communication with an interrogator, the contactless data carrier comprising:

• a measurement port for receiving an external signal to be compared, from a signal source that generates the external signal according to an ambient physical quantity;
• a variable threshold generator for generating different threshold values;
• a comparator for comparing the external signal received at the measurement port with the different threshold values and for producing comparison results;
• and
• a controller for receiving signals specifying the different threshold values from the interrogator, for controlling the variable threshold generator according to the signals received from the interrogator, and for returning each of the comparison results to the interrogator, the code comprising:
• a first program, installable in the interrogator, for
• sending, from the interrogator, the controller in the contactless data carrier a command to have the comparator execute the repeated comparisons with different threshold values,
• sending, from the interrogator, the contactless data carrier the different threshold values,
• receiving, by means of the interrogator, individual results of the comparisons from the contactless data carrier, and
• obtaining, by means of the interrogator, information about the ambient physical quantity by finding a boundary threshold value at which the results of the comparisons change;
• and
• a second program installable in the contactless data carrier, for
• controlling, by means of the controller, the comparator according to commands received from the interrogator,
• executing said command to have the comparator execute repeated comparisons with different threshold values, and
• returning, from the contactless data carrier, the comparison results to the interrogator.