GB2137386A

GB2137386A - Data acquisition system

Info

Publication number: GB2137386A
Application number: GB08400616A
Authority: GB
Inventors: Hugh Tomlinson
Original assignee: Tri Scan Ltd
Current assignee: Tri Scan Ltd
Priority date: 1983-01-11
Filing date: 1984-01-11
Publication date: 1984-10-03
Also published as: GB8400616D0; GB2137386B

Abstract

A data acquisition system comprising a data-carrying member coded with information by means of a predetermined array of permanent magnets carried by the data member, and a reader head which includes a plurality of Hall effect sensing devices adapted to respond to the magnets on the data member when the data member and reader head are brought into juxtaposition. The information on the data member can then be accessed by scanning and operating on the electrical signals obtained from the Hall effect sensing devices. The data member and reader head are held in their mutually co-operative operating positions by means of further permanent magnets and keeper plates disposed on the reader head and data member, respectively.

Description

SPECIFICATION Data acquisition system The present invention relates to data acquisition systems and is concerned particularly, but not exclusively with such systems for use in fuel man agement.

A number of systems for fuel management are currently available. These are used, for example, for the control and monitoring of fuel supplied to vehicle fleets so that information can be recorded and stored regarding such details as vehicle fleet identification number, type of vehicle, the product that the vehicle carries, the amount of fuel supplied, the date, the time, etc.

One known system employs pre-coded keys or cards which are carried by the driver or with the vehicle. The key or card bears the relevant information on it, either by way of the mechanical configuration in the case of a key or by magnetic strips in the case of a card. In use, the key or card is inserted into a fixed terminal near the fuel pump, the information is read by some suitable form of reader and access is allowed or denied to the pump accordingly. The main problem with such systems is that the keys or cards can be exchanged amongst the drivers or even lost altogether, thereby breaching or limiting the security of the system.

Another known system uses a memory device fixed to the vehicle which is coupled by the vehicle driver to a fixed reader device by way of a conventional plug and socket connection and electrical leads. The principal problem with such plug and socket connections is that, as frequently happens, the vehicle driver forgets to unplug the system from the vehicle before driving away - the result being that the plug is dragged from the socket and damaged or destroyed.

It is an object of the present invention to provide a method of transferring data from the vehicle to the fixed reader which does not have the disadvantages of the known systems described above.

A system in accordance with the present invention comprises a respective data-carrying member attached to each vehicle, each data member being coded with information by means of a predetermined array of permanent magnets carried by the data member, and a reader head which includes a plurality of Hall effect sensing devices adapted to respond to the magnets on the data member when the data member and reader head are brought into juxtaposition, whereby the information on the data member can be accessed by scanning and operating on electrical signals obtained from the Hall effect sensing devices.

Each data-carrying member (data member) can conveniently comprise a plastics moulding loaded with small magnets, such as bremag or corameg disc magnets (e.g. each being 6x2mm). These magnets provide the coding elements for the member.

Also mounted in the moulding are two keeper plates which are adapted to mate with retaining magnets housed in the reader head. Typically, there are basically 32 coding magnets in each data member, although this number can be increased or reduced to suit requirements. The locations for the 32 magnets are set in an array on the data member which matches the array of Hall effect sensing elements in the reader head.

The reader head is preferably housed in a rugged steel case which is attached to the end of an umbilical cord leading to a reader terminal. Just under the surface of the reader head face is the array of Hall effect devices, positioned in the same matrix layout as the coding magnets. The sides of the data member are arranged to locate with the inside surfaces of the reader head, whereupon strong magnets (not coding magnets) carried by the reader head or the vehicle latch onto keep plates fitted to the data member, thus holding the reader head in position in relation to that data member.

The data is then read from the data member by means of the Hall effect devices. These devices are arranged either to "turn on" or alternatively to "turn off" when subjected to the correct pole of magnetism. Each data member is encoded with its unique code either by fitting or not fitting the coding magnets of the basic array, on that data member, or by fitting all magnets in the array but reversing the ones that do not form part of the unique code, or vice versa. The data may, for example, be strobed from the head in 4 eight bit words, or could be 32 bit parallel or completely serial. The reader head can carry two or more extra Hall effect devices providing "locator bits", such that it is only when these bits are made, i.e. "turned on", that the head is read. This is done to ensure that misreads cannot occur.

To ensure compliance with the relevant B.A.S.E.E.F.A. regulations, the reader head on the umbilical is mounted at a fuel pump island assembly on a tall post. At the full extent of its arc of swing, the reader head is preferably arranged to be held (by the umbilical) above a predetermined zone adjacent the ground.

The invention is described further hereinafter by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an exploded perspective view of the general assembly of the reader head; Figure 2 is a sectional view through the reader head of Figure 1 when in the assembled state; Figures 3a, 3b and 3c are front, sectional side and sectional end views of a data-carrying member, with the coding magnets removed; and Figures4and 5aretwo diagrammaticfrontand side views of a typical pump island installation, showing the disposition of the reader head and reader terminal.

With reference to Figures 1 and 2, the reader head comprises a case 10 into which are fitted a printed circuit board 12, a polycarbonate board 14 having an array of holes 16 each of which receives a respective Hall effect sensor (not shown) coupled to the circuit board 12, a pair of permanent magnet assemblies 18, 20, and a label 22 of anodised aluminium. The aforegoing elements are held in position in the housing with the aid of a front bezel 24.As best seen in Figure 2, the front bezel 24 presents a bevelled inside surface forming a female socket for receiving a correspondingly bevelled data-carrying member 26 configured as shown in Figures 3a to 3c. (Figures 3a to 3c are in fact drawn to a smaller scale than Figure 2 and in practice the data member is dimensioned to be received snugly within the socket defined by the front bezel 24 of the reader head.) Th magnet assemblies 18, 20 comprise groups of powerful permanent magnets, (such as Ticanam Super Senior 26) adapted to latch onto keep plates (not shown) mounted on the data member whereby to hold the data member and reader head in their operational positions. The keep plates are disposed in recesses 28 on the front of the data member. The data member has a recess 30 on its rear surface for receiving an insert containing the array of permanent magnets (not shown).The array of permanent magnets is thus not visible externally of the data member in this embodiment.

Figures 4 and 5 show how the reader head 34 is connected to a reader terminal 36 by an umbilical cable 38, the top end of which is coupled to a tall pillar 40 by way of a Kopex (Trade Mark) adaptor 42.

When extended, the limit of the reader head 34 is indicated by the broken line A whereby the displacement of the head is confined to zone 2 and out of zone 1.

With the advent of new, more sensitive Hall effect devices, it is possible to replace the discrete permanent magnets with a corresponding pattern permanently programmed into a magnetisable medium, using the techniques known from magnetic card technology.

It is also possible to use devices other than Hall effect elements for sensing the magnetic fields of the coding elements. For example, this could be achieved using tuned coils or even reed-type switches.

It will be be appreciated that a system in accordance with the present invention overcomes the problems of the known prior art in that (a) it does not use a loose key or card which can be lost, stolen or exchanged, and (b) the nature of the magnetic coupling between the reader and the data-carrying member that the connection can be broken by pulling on one or other ofthe data card and reader head without damage to the system - even if the vehicle were to be driven away with the connection still made.

It will also be appreciated that the present system can be used in situations other than for fuel management where access to data is to be made available between two basically separate bodies.

Claims

1. A data acquisition system comprising a datacarrying member which is coded with information by means of a predetermined magnetic array carried by the data member, and a reader head which includes a plurality of sensing devices adapted to respond to the magnetic array on the data member when the data member and reader head are brought into juxtaposition, whereby the information on the data member can be accessed by scanning and operating on electrical signals obtained from the sensing devices.

2. A data acquisition system comprising a plurality of data-ca ing members attached respectively to each of a plurality of vehicles, each data member being coded with informaton by means of a predetermined magnetic array carried by that member, and a reader head which includes a plurality of sensing devices adapted to respond to the magnetic array on the data member when the reader head and a selected data member are brought into juxtaposition, whereby the information on that data member can be accessed by scanning and operating on electrical signals obtained from the sensing devices.

3. A data acquisition system comprising a datacarrying memberwhich is coded with information by means of a predetermined array of permanent magnets carried by that member, and a reader head which includes a plurality of Hall effect sensing devices adapted to respond to the magnets on the data member when the data member and reader head are brought into juxtaposition, wherebythe information on the data member can be accessed by scanning and operating on electrical signals obtained from the Hall effect sensing devices.

4. A data acquisition system comprising a plurality of data-carrying members attached respectively to each of a plurality of vehicles, each data member being coded with information by means of a predetermined array of permanent magnets carried by that member, and a reader head which includes a plurality of Hall effect sensing devices adapted to respond to the magnets on the data member when the reader head and a selected data member are brought into juxtaposition, whereby the information on that data member can be accessed by scanning and operating on electrical signals obtained from the Hall effect sensing devices.

5. A data acquisition system as claimed in claim 3, or 4 wherein each data member comprises a plastics moulding loaded with said predetermined array of permanent magnets providing coding ele ments for that data member.

6. A data acquisition system as claimed in claim 5, wherein each data member includes two ferromagnetic keeper plates which are adapted to mate with retaining magnets housed in the reader head for holding the data member and reader head in juxtaposed operational positions.

7. A data acquisition system as claimed in claims 1, 2, 3, or 4 wherein each data member is encoded with its own unique code by fitting or omitting the coding magnets of the basic array on that data member.

8. A data acquisition system as claimed in claims 1, 2, 3, or 4 wherein each data member is encoded with its own unique code by fitting all magnets in the array but reversing the polarity of the ones that do not form part of the unique code for that data member, or vice versa.

9. A data acquisition system as claimed in any of claims 1 to 6 wherein, in addition to the Hall effect sensing devices for reading information from said array of magnets, two or more extra Hall effect devices provide location indicators such that it is only when these indicators are activated that the reader is read.

10. A data acquisition system as claimed in any of claims 1 to 7 wherein the reader head is housed in a casing attached to a reader terminal by way of a flexible umbilical cable.

11. A data acquisition system as claimed in any of claims 1 to 3 wherein the array of Hall effect devices is disposed just under the surface of a front face of the reader head, the outer sides of the data member being arranged to locate with inside surfaces of the reader head, whereupon strong magnets carried by the reader head latch onto keeper plates on the data member whereby to hold the reader head in position in relation to that data member.

12. A data acquisition system substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.