GB2289553A

GB2289553A - Remote computer access using radio

Info

Publication number: GB2289553A
Application number: GB9509725A
Authority: GB
Inventors: Stephen Jeffrey; Brian Douglas; George Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-05-14
Filing date: 1995-05-13
Publication date: 1995-11-22
Anticipated expiration: 2015-05-13
Also published as: GB9409690D0; GB9509725D0; GB2289553B

Abstract

Data display apparatus for displaying data at locations remote from a host computer, in which requests for data to be displayed are transmitted from a hand-held display unit (22) to the host computer via a UHF radio link and data is transmitted from the host computer to the hand-held unit in response to such requests. The host computer is provided with an expansion card having radio modem means for connection to a conventional UHF radio unit. The display unit (22) includes an LCD display (24) and input keys (32, 36), and a radio modem also adapted for connection to a conventional UHF radio (28). The system provides different modes of data transmission, having differing levels of redundancy in the transmitted data, and is particularly intended for use in the offshore oil industry. <IMAGE>

Description

"Radio Data Display System" This invention relates to a data display system having a radio communication link to a host computer, whereby data from the host may be displayed at a remote location via the radio link. In its preferred configuration the invention comprises a hand held unit using a UHF radio link and providing for remote selection of one of a plurality of screensful of data from the host. The invention is intended primarily, but not exclusively, for use in the offshore oil industry.

Conventional data terminals are connected to host computers via cables. In offshore situations, this means that historical data and/or real time operational data are only available to personnel at a limited number of fixed locations.

This means that operations such as, for example, instrument calibration, become highly labour intensive.

Offshore data-logging operations are generally carried out by sub-contractors who themselves move frequently between different offshore installations, so that a significant amount of time and effort is expended on cable pulling. Once the data logging equipment is installed, supervisory personnel have to spend a great deal of time on the telephone having data relayed to them when they are working away from a data terminal.

Besides limiting the availability of data, cabling is expensive to install and is liable to physical deterioration and damage.

In accordance with the invention there is provided data display apparatus comprising a visual display unit adapted to display data generated by a remote host computer and radio communication means including data modulation means and radio transmitter means connectable to the host computer and radio receiver means and data demodulation means associated with the visual display unit.

Preferably, the apparatus is adapted to allow the data to be displayed to be selected by a user of the visual display unit, the apparatus further including data input, data modulation and radio transmitter means associated with the visual display unit, and radio receiver and data demodulation means associated with the host computer.

Preferably, said data input means comprises keypad means.

Preferably also, said data modulation and/or demodulation means associated with the host computer is located on an expansion card adapted to be fitted in an expansion slot of the host computer. The radio transmitter/receiver means of the host computer may comprise an external unit adapted to be connected to said expansion card, or may be incorporated into said expansion card.

Preferably also, said visual display unit and its associated data modulation/demodulation means and data input means are enclosed in a common casing adapted to be connected to separate radio receiver/transmitter means. Alternatively, the visual display unit, data modulation/demodulation means, data input means and radio receiver/transmitter means are all combined in a single unit. In either case, it is preferred that the apparatus remote from the host is adapted for hand-held use.

Preferably also, the visual display unit comprises an LCD display together with microprocessor means and memory means.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a schematic front view showing the general arrangement of a hand-held data display unit in accordance with the invention; Fig. 2 is a schematic front view showing the general arrangement of a host computer system in accordance with the invention; Figs. 3(a) to 3(e) are schematic block diagrams illustrating the circuitry of the hand-held unit of Fig. 1; Fig. 4 is a schematic block diagram illustrating the host computer system of Fig.

2; Fig. 5 shows the pin layout of a connector for connecting the hand-held unit of Fig. 1 and the computer of Fig. 2 to conventional UHF radio units; Fig. 6 is a circuit diagram of system electronics associated with the computer of Fig. 2; and Fig. 7 is a circuit diagram of the system electronics of the hand-held unit of Fig. 1.

Referring now to the drawings, the invention provides a hand-held data display system with remote screen selection, based on a pair of UHF hand-held radios.

The system is designed to be compatible with instations using stand-alone or LAN linked personal computers (PC's) or similar. The system comprises a hand-held unit (the "outstation") and a suitably adapted host computer, the hand-held unit being adapted to receive and display data transmitted from the host computer (the "instation"), with the facility for the user of the hand-held unit to select different screens of data to be displayed.

In this example, the instation electronics for the system are contained on a standard PC expansion slot board which is connected directly to the instation radio. The outstation hand-held unit includes a support clip and cable for connection to the outstation radio and, in this example, provides a 240 by 128 pixel LCD display.

The instation PC is mains powered, while the instation radio may run on its integral battery, or via a mains adapter. The outstation radio also uses its integral battery while the associated hand-held display unit has a separate rechargeable battery pack. The radio batteries are recharged using their own charger units.

The battery pack of the display unit is recharged using a standard mains adapter.

Operation of the system involves the transmission of a code number, identifying the desired screen of information, from the hand-held unit to the instation, which in turn transmits the selected screen of information. In the present example, a screen of information comprises an array of 16 by 32 characters.

The instation PC's own local display may also indicate the screen being viewed by the remote unit. Graphical information might also be transmitted. However, this would generally involve an increased transmission time.

A typical data screen would normally be displayed within 5 to 10 seconds, including the access time for a standard PC disk drive. Data already resident in the random access memory (RAM) of the instation computer will always be transmitted more quickly than disk based information. Similarly, the total refresh time for a screen already in use will always be shorter than when a new screen is selected.

Figs 1 and 2 illustrate the physical arrangement of the outstation and the instation, respectively.

Referring to Fig. 2, the instation consists of a standard desktop PC 10 having its own display 12 and keyboard 14, and having a custom designed expansion board (not visible in Fig. 2), providing the instation system electronics, fitted in one of its expansion slots. This board provides for two cable links 16, 18: one from the board to the standard RS232 Port at the rear of the PC 10 and one to the instation UHF radio 20, which would normally be located within 5 or 6 feet of the PC 10.

Referring to Fig. 1, the outstation consists of a handheld assembly made up of a housing 22 containing a custom circuit board (not visible in Fig. 1) and associated LCD display 24, with an external clip 26 for supporting the outstation UHF radio 28. Connection between the radio 28 and the housing 22 is via a single cable connection 30. On the rear of the housing 22 is located an 8.4 Volt NiCad rechargeable battery pack (not shown) with a fuse holder and charger connector.

On the front face of the housing 22 is the display screen 24 and a four-way, sealed keypad 32, suitably including "arrow-up" and "arrow-down" keys, a "TX" key and an "E" key. Access is provided on the base of the housing 22 to an LCD contrast control 34 and to a further, concealed 4 by 3 keypad 36 for the entry of security PIN codes and the like.

In this embodiment, the system uses conventional handheld UHF radio units at both the instation and the outstation, for data transmission and reception. Such units will include conventional controls, including on/off, volume, channel select, "press to transmit" (PTT) etc.

Figs. 3 and 4 show block diagrams of the electronics of the hand-held outstation unit and of the instation computer respectively, whilst Figs. 6 and 7 show corresponding circuit diagrams. Fig. 5 shows the pin layout for the cable connections between the instation PC and the outstation hand-held unit and their respective UHF radios.

Referring firstly to the instation system, the electronics specific to the system are housed on the PC expansion board 38 (Figs. 4, 6). The board can be seen to consist essentially of a radio modem circuit built around a 7910 device, U1. A conventional RS232 interface formed at PL1 uses driver/receiver IC's U2 (1489) and U4 (1488). Connections to the PC power supply rails is via CNB1, providing +5 Volts, +12 Volts and -12 Volts. The modem IC U1 produces a radio compatible signal at TC (U1, pin 8) which is a.c.

coupled via capacitor C3 to an op-amp U3A. The output of the op-amp U3A is fed via pin 9 of connector SK1 to the UHF radio "audio-in" connection (see Fig. 5).

Received data from the UHF "audio out" connection is a.c. coupled into a further op-amp U3B, and so to input RC (U1. pin 5) of the modem IC U1. During transmission, transistor Q1 is switched on by the PC RTS line (SK1, pin 7). This provides the PTT (press to talk) signal to the radio 20.

Referring now to the outstation system (Figs. 3, 7), this is designed around an 80C535 microprocessor IC3, with an 8Kb EPROM IC9 and 8Kb RAM IC10. The bus of the processor IC3 is demultiplexed by IC8 which latches the 8 LS address lines using "ALE" while IC7 (HC138) provides the address decode selecting the RAM IC10 and ROM IC9 via the signals /RAMEN and /ROMEN.

IC6 provides for a conventional read from the EPROM IC9 as well as a program read.

The operators keys are scanned by a single 16-1 line multiplexer IC4 which allows the 16 inputs from the 1 by 4 and 4 by 3 keypads 32, 36 to be input.

Individually, keys close to 0V, ie they are not arranged as a matrix. The scanning of the keys is achieved by the address bits KO - K3 inclusive and the selected key input, which is low for "key pressed", appears at IC4, pin 1 (KB), and so to IC3, pin 25.

The LCD display 24 is connected via a 20 way flexistrip to CNX. In this embodiment, the display is suitably a LMG640X unit from Hitachi. The conventional logic +5 Volt supply is fed to the display via pins 1 and 2 while -12 to -15 Volt supply is wired to pin 17. The varying voltage at pin 3 provides contrast control using variable resistor RV3 (34). The negative supply is derived from the +5 Volt rail by IC5. REG1 provides the +5 Volt rail from the +8.4 Volt battery supply.

The modem IC1 is wired to the processor IC3 via the RXD and TXD (IC3 pins 21 and 22) and the "carrier detect" signal is presented to IC3 pin 24. Input and output signals from/to the UHF radio 28 are processed by dual op-amps U2(A) and U2(B). These circuits are substantially identical to those used by the instation modem.

Operation of the system will now be described.

When the instation equipment is switched on, a link is established to the PC software which will provide the data screens to be used by the system. When the outstation equipment is switched on, an initial menu is displayed allowing the SCREEN NUMBER and MODE NUMBER to be selected using the up and down arrow keys of the 4way keypad 32. This menu may also provide an option for secure transmission. The MODE NUMBER selects the method of data transmission, with higher mode numbers corresponding to higher levels of redundancy in the data, allowing for lower radio link quality.

Once selected, the screen number is transmitted by pressing the TX key, whereafter the corresponding data screen will be transmitted by the instation system and will be displayed on the LCD display 24. A "refresh" of the screen currently being viewed can be obtained simply by pressing the TX key again. The "E" key will allow a return to the opening menu. Should data not be received, a "DATA ERROR" message will be displayed.

The "E" key will always return the operator to the initial menu from this condition.

The concealed 4 by 3 keypad 36, if provided, will offer a PIN number facility providing a level of data protection in the "secure" mode. Data encoding is introduced when secure mode operation is selected. In this event, the unit requests the operator to enter his/her PIN number, allowing access to those screens for which the operator has the required clearance.

The secure mode may be used, for example, to allow different sub-contractors working on a site to view only those data screens relevant to their part of a contract. Access to all screens would be available only, say, to the consultants responsible for the whole contract.

Whilst the present embodiment utilises existing handheld UHF radio units which are connected to the instation PC and outstation display unit respectively, it will be understood that the apparatus could be further modified to incorporate the radio transceivers into the PC expansion board and/or the outstation display. However, in an environment where existing radio units are readily available, the configuration of the system to operate with existing radio units may be considered advantageous.

Generally, the invention allows data from a host computer to be accessed at any arbitrary location via radio link, as compared with cabled systems in which access is only possible from fixed points. In the context of an offshore installation, the following advantages are obtained: 1 Instant access to real-time operations data from anywhere on the installation.

2 No need for cabling to be run at start up of new contracts.

3 Instrument calibration becomes a one man operation.

4 Improved safety with remote data monitoring available during emergency situations such as evacuations.

Improvements and modifications may be introduced without departing from the scope of the invention as defined in the appended Claims.

Claims

1. Data display apparatus comprising a visual display unit adapted to display data generated by a remote host computer and radio communication means including data modulation means and radio transmitter means connectable to the host computer and radio receiver means and data demodulation means associated with the visual display unit.

2. Apparatus as claimed in Claim 1, said apparatus being further adapted to allow the data to be displayed to be selected by a user of the visual display unit, the apparatus further including data input, data modulation and radio transmitter means associated with the visual display unit, and radio receiver and data demodulation means associated with the host computer.

3. Apparatus as claimed in Claim 2, wherein said data input means comprises keypad means.

4. Apparatus as claimed in Claim 3, wherein said keypad means includes control keys whereby options may be selected from a menu displayed on said visual display unit, and a transmit key for sending data to said host computer.

5. Apparatus as claimed in Claim 4, wherein said menu allows a user to select one of a plurality of data screens to be displayed, whereafter operation of said transmit key causes a signal to be transmitted identifying the selected data screen, said host computer being adapted to transmit the selected data screen in response to reception of said signal.

6. Apparatus as claimed in Claim 4, wherein said menu allows a user to select one of a plurality of data transmission modes, said data transmission modes having ditfering levels of redundancy in the transmitted data.

7. Apparatus as claimed in any one of Claims 3 to 6, wherein said keypad means includes a concealed keypad for the entry of security codes or the like.

8. Apparatus as claimed in any preceding Claim, wherein said data modulation and/or demodulation means associated with the host computer is located on an expansion card adapted to be fitted in an expansion slot of the host computer.

9. Apparatus as claimed in Claim 8, wherein the radio transmitter/receiver means of the host computer comprises an external unit adapted to be connected to said expansion card.

10. Apparatus as claimed in Claim 9, wherein said expansion card includes connector means for connecting said expansion card to said external radio unit.

11. Apparatus as claimed in Claim 8, wherein the radio transmitter/receiver means of the host computer is incorporated into said expansion card.

12. Apparatus as claimed in any one of Claims 8 to 11, wherein said expansion card includes connector means for connecting said expansion card to an input/output port of the host computer.

13. Apparatus as Claimed in any preceding Claim, wherein said visual display unit and its associated data modulation/demodulation means and data input means are enclosed in a common casing adapted to be connected to separate radio receiver/transmitter means.

14. Apparatus as claimed in any one of Claims 1 to 12, wherein the visual display unit, data modulation/demodulation means, data input means and radio receiver/transmitter means are all combined in a single unit.

15. Apparatus as claimed in Claim 13 or Claim 14, wherein the apparatus remote from the host is adapted for hand-held use.

16. Apparatus as claimed in any preceding Claim, wherein the visual display unit comprises an LCD display together with microprocessor means and memory means.

17. A hand-held visual display unit as defined in any preceding Claim.

18. A computer expansion card as defined in any preceding Claim.

19. A computer as defined in any preceding Claim adapted for use with the hand-held visual display unit of Claim 17.

20. Data display apparatus substantially as hereinbefore described with reference to the accompanying drawings.

20. A hand-held visual display unit substantially as hereinbefore described with reference to the accompanying drawings.

21. A computer expansion card substantially as hereinbefore described with reference to the accompanying drawings.

22. A computer adapted for use in a data display system substantially as hereinbefore described with reference to the accompanying drawings.