Inductive loop diagnostic interface

• US 5,621,661 A
• Filed: 08/03/1994
• Issued: 04/15/1997
• Est. Priority Date: 08/04/1993
• Status: Expired due to Term

• Current Assignee: Nortech International (Proprietary) Limited
• Original Assignee: Electromatic (Proprietary) Limited
• Inventors: Farrow, Cyril A.
• Primary Examiner(s): Voeltz, Emanuel T.
• Assistant Examiner(s): PIPALA, EDWARD J
• Application Number:
  US08/285,119
• Time in Patent Office: 986 Days
• Field of Search: 364/516, 364/550, 364/436-438, 340/870.01, 340/870.07, 340/870.16, 340/870.28, 340/870.29, 340/933, 340/941
• US Class Current: 340/941
• CPC Class Codes: G08G 1/0104 Measuring and analyzing of parameters relative to traffic conditions
• CPC Class Codes: G08G 1/042 using inductive or magnetic detectors
• CPC Class Codes: H04B 10/114 Indoor or close-range type systems

Abstract

A method of obtaining data relating to the performance of an inductive loop detector wherein a light source is modulated with a signal which is dependent on the data and the modulated signal is remotely detected and data extracted therefrom is stored for later processing.

Claims

1. An inductive loop vehicle detector comprising:

an inductive loop mountable in a pavement structure; and

a detector unit connected to the loop wherein the detector unit includes;

a signal source for energizing the loop;

control means for monitoring the loop and generating diagnostic data relating to operation of the loop and the signal source;

memory means for storing the diagnostic data generated; and

optical output means for producing an optical output signal, the optical output means being controlled by the control means so that the optical output signal is repetitively modulated by a modulation signal based on the stored diagnostic data at a rate such that the data is not discernible by a human.

2. A data receiving device for use in receiving diagnostic data relating to performance of an inductive loop vehicle detector, the detector including an inductive loop and a detector unit connected to the loop having an optical output means for emitting a modulated optical signal, the data receiving device comprising:

optical energy receiving means for receiving the modulated optical signal emitted from the optical output means of the detector unit,

demodulating means for extracting data from the modulated optical signal, the data being associated with a signal used to modulate the optical output means in the detector unit;

data storage means for storing the data extracted by the demodulating means; and

means for retrieving the stored data from the data storage means.

3. A system for transferring diagnostic data relating to an inductive loop vehicle detector, the system comprising:

an inductive loop vehicle detector; and

a data receiving device;

wherein the inductive loop vehicle detector includes;

an inductive loop mountable in a pavement structure; and

a detector unit connected to the loop, the detector unit having a signal source for energizing the loop, control means for monitoring the loop and generating diagnostic data relating to operation of the loop and the signal source, memory means for storing the diagnostic data generated, and optical output means for emitting a modulated optical output signal, the optical output means being controlled by the control means so that the optical output signal is modulated by a modulation signal based on the stored diagnostic data at a rate such that the data is not discernible by a human; and

wherein the data receiving device includes;

optical energy receiving means for receiving the modulated optical signal emitted from the optical output means of the detector unit,

demodulating means for extracting data from the modulated optical signal, the data being associated with the signal used to modulate the optical output means in the detector unit;

data storage means for storing the data extracted by the demodulating means; and

means for retrieving the stored data from the data storage means.

4. A method of transferring diagnostic data from an inductive loop vehicle detector having an inductive loop and a detector unit connected to the loop, the method comprising:

continually generating diagnostic test data relating to performance of the loop;

storing the generated diagnostic test data in a memory of the detector;

repetitively modulating at least one optical signal output device with the stored data to emit a modulated optical signal, the modulation being at a rate wherein the data is not discernible by a human viewing the emitted modulated optical signal;

detecting with a portable data reading device the emitted modulated optical signal and extracting the data therefrom;

storing data extracted with the reading device; and

retrieving the extracted data.