Sensing device arrangement for fuel storage tanks

• US 7,825,816 B2
• Filed: 08/20/2007
• Issued: 11/02/2010
• Est. Priority Date: 08/20/2007
• Status: Active Grant

• Current Assignee: OPW Fuel Management Systems Inc. (Dover Corporation)
• Original Assignee: Delaware Capital Formation Incorporated (Dover Corporation)
• Inventors: Iwaszczyszyn, Przemyslaw Olaf, Jarvie, Ian F.
• Primary Examiner(s): Nguyen; Phung
• Application Number:
  US11/841,465
• Publication Number:
  US 20090051554A1
• Time in Patent Office: 1,170 Days
• Field of Search: 340/612, 340/622, 340/614, 340/632, 340/618, 340/611
• US Class Current: 340/612
• CPC Class Codes: B65D 88/76 for use underground manholes, inspection openings, covers therefor B65D90/105; special vessels for collecting or storing rain-water for use in the household E03B3/03; cesspools E03F11/00
• CPC Class Codes: B65D 90/48 Arrangements of indicating or measuring devices
• CPC Class Codes: B67D 7/3209 relating to spillage or leakage, e.g. spill containments, leak detection leak detectors for underground fuel dispensing systems G01M3/2892
• CPC Class Codes: G01M 3/186 for containers, e.g. radiators
• CPC Class Codes: G01M 3/2892 for underground fuel dispensing systems G01M3/30 takes precedence

Abstract

A sensing device arrangement for a fuel storage system is provided having at least one storage tank, a plurality of sensing devices positioned in or around the at least one storage tank, and a controller in electrical communication with the plurality of sensing devices. The controller is configured to communicate with each sensing device of the plurality of sensing devices on a single bi-directional data line. A sensing device of the plurality of sensing devices is activated by the controller. Data is acquired by the sensing device and transmitted to the controller over the data line. The controller instructs the sensing device to change to a low power state. The controller receives electrical characteristics from the plurality of sensing devices recognized on the data line and calculates a characteristic of the sensing device arrangement. The controller verifies compliance with an intrinsic safety barrier.

Claims

1. A sensing device arrangement for a fuel storage system comprising:

at least one storage tank;

a plurality of sensing devices positioned in or around the at least one storage tank; and

a controller in electrical communication with the plurality of sensing devices, the controller configured to communicate with each sensing device of the plurality of sensing devices on a single bi-directional data line,

wherein the electrical communication is configured to use an asynchronous communications protocol and comprises;

a multi-drop configuration of the plurality of sensing devices communicating over the single bi-directional line.

2. The sensing device arrangement of claim 1 wherein the sensing devices are operable to monitor a property of a fluid in the storage tank.

3. The sensing device arrangement of claim 2 wherein the sensing devices comprise probes and wherein the probes are configured to monitor a property selected from the group consisting of a level of the fluid in the storage tank, a temperature of the fluid in the tank, a pressure of the fluid in the tank, a density of the fluid in the tank, and combinations thereof.

4. The sensing device arrangement of claim 1 wherein the sensing devices are operable to monitor a property outside of the tank.

5. The sensing device arrangement of claim 4 wherein the sensing devices comprise sensors and wherein the sensors are configured to monitor properties selected from the group consisting of temperature, pressure, hydrocarbon levels, and combinations thereof.

6. The sensing device arrangement of claim 1 wherein a sensing device of the plurality of sensing devices comprises:

an interface component having a microprocessor operable to communicate with the controller; and

an active or passive sensing component electrically coupled to the interface component.

7. The sensing device arrangement of claim 6 wherein the interface component is operable to store a unique identifier for the sensing device.

8. The sensing device arrangement of claim 6 wherein the interface component is operable to store sensing device characteristics selected from the group consisting of voltage, current, capacitance, inductance, threshold values, manufacturer, manufactured date, software version, and combinations thereof.

9. A method of sensing a property in or outside of a fuel storage tank by a plurality of sensing devices in a multi-drop configuration, the method comprising:

activating a sensing device of the plurality of sensing devices by a controller;

acquiring data by the sensing device;

transmitting the data from the sensing device to the controller over a single bi-directional data line; and

instructing the sensing device to change to a low power state by the controller,

wherein the data transmission uses an asynchronous communications protocol.

10. The method of claim 9 further comprising:

activating a subsequent sensing device of the plurality of sensing devices by the controller;

acquiring data by the subsequent sensing device;

transmitting the data from the subsequent sensing device to the controller over the single bi-directional data line; and

instructing the subsequent sensing device to change to a low power state by the controller.

11. The method of claim 9 wherein transmitting the data comprises:

comparing the data to a threshold value for the sensing device; and

in response to exceeding the threshold value, transmitting the data from the sensing device to the controller.

12. The method of claim 11 wherein transmitting the data further comprises:

periodically transmitting the data from the sensing device to the controller regardless of the threshold value.

13. The method of claim 9 wherein the sensing device is a probe and wherein acquiring data comprises:

measuring a property selected from the group consisting of a level of the fluid in the storage tank, a temperature of the fluid in the tank, a pressure of the fluid in the tank, a density of the fluid in the tank, and combinations thereof.

14. The method of claim 9 wherein the sensing device is a sensor and wherein acquiring data comprises:

measuring a property selected from the group consisting of temperature, pressure, hydrocarbon levels, and combinations thereof.

15. A method of recognizing sensing devices in a sensing device arrangement for a fuel storage system, the method comprising:

recognizing a plurality of sensing devices by a controller over a single bi-directional data line;

broadcasting a discovery message from the controller to a plurality of sensing devices in electrical communication with the controller over the single bi-directional data line;

transmitting a sync character from the controller to the plurality of sensing devices over the single bi-directional data line; and

transmitting a unique identification from a sensing device of the plurality of sensing devices to the controller over the single bi-directional data line.

16. The method of claim 15 further comprising:

in response to receiving the unique identification, transmitting a silencing instruction from the controller to the sensing device,

wherein the silencing instruction causes the sensing device to ignore further discovery messages and sync characters sent from the controller.

17. The method of claim 15 further comprising:

broadcasting a subsequent discovery message from a controller to a plurality of sensing devices in electrical communication with the controller over the single bi-directional data line;

transmitting a subsequent sync character from the controller to the plurality of sensing devices over the single bi-directional data line; and

transmitting a unique identification from a subsequent sensing device of the plurality of sensing devices that has not received a silencing instruction to the controller over the single bi-directional data line.

18. The method of claim 17 further comprising:

in response to receiving the unique identification, transmitting a silencing instruction from the controller to the subsequent sensing device.

19. The method of claim 15 wherein individually retrieving the unique identification comprises at a sensing device of the plurality of sensing devices:

monitoring the single bi-directional data line connecting the plurality of sensing devices to ascertain if another sensing device of the plurality of sensing devices is already transmitting; and

in response to no transmissions on the single bi-directional data line,

transmitting a first byte of the unique identification of the sensing device to the controller,

receiving a subsequent sync character from the controller, and

in response to receiving the subsequent sync character, transmitting a next byte of data representing the unique identification of the sensing device to the controller.

20. The method of claim 19 further comprising in response to no transmissions on the single bi-directional data line:

receiving from the controller a silencing instruction to change from an active state to a low power state and ignore further discover message broadcasts and sync characters from the controller.

21. The method of claim 19 wherein transmitting a byte of data comprises:

driving the single bi-directional data line high when transmitting a bit value of one (1);

passively allowing a pull down resistor to pull the single bi-directional data line low when transmitting a bit value of zero (0);

monitoring the single bi-directional data line when transmitting the bit value of zero (0); and

in response to a high value on the date line when transmitting the bit value of zero (0), ignoring the subsequent sync character until a subsequent broadcast of a discovery message.

22. The method of claim 21 wherein driving the ling high comprises driving the line to approximately 5 volts.

23. The method of claim 21 wherein pulling the line low comprises pulling the line to approximately 0 volts.

24. The method of claim 19 further comprising:

transmitting a characteristic of the sensing device with the unique identification to the controller.

25. The method of claim 24 wherein transmitting the characteristic comprises:

transmitting a characteristic from a group consisting of a type of sensing device, a voltage level of the sending device, a current level of the sensing device, a capacitance of the sensing device, an inductance of the sensing device, a description of the sensing device, a manufacturing date of the sensing device, a software version used with the sensing device, and combinations thereof.

26. A method of determining compliance between a sensing device arrangement and an intrinsic safety barrier for a fuel storage system, the method comprising:

broadcasting a discovery message over a single bi-directional data line to discover a plurality of sensing devices;

receiving at a controller, electrical characteristics of the plurality of sensing devices;

calculating a characteristic of the sensing device arrangement using the characteristics transmitted by the plurality of sensing devices; and

verifying compliance with the intrinsic safety barrier.

27. The method of claim 26 further comprising:

in response to the characteristic of the sensing device arrangement being out of compliance with the intrinsic safety barrier, shutting down the sensing device arrangement.

28. The method of claim 26 wherein transmitting the characteristic comprises:

transmitting a characteristic from a group consisting of a voltage level of the sending device, a current level of the sensing device, a capacitance of the sensing device, an inductance of the sensing device, and combinations thereof.