GB2156128A

GB2156128A - Electronic guard patrol systems

Info

Publication number: GB2156128A
Application number: GB08507727A
Authority: GB
Inventors: Robin Michael Harding; John Neil Mudford
Original assignee: BRITONICS Ltd
Current assignee: BRITONICS Ltd
Priority date: 1984-03-24
Filing date: 1985-03-25
Publication date: 1985-10-02
Also published as: GB2156128B; GB8507727D0

Abstract

An electronic guard patrol system and a portable clock unit for use in the electronic guard patrol system, the electronic clock unit including a single connector which co-operates both with the connection terminals of each key station and also on the central control apparatus. The electronic control unit is able to identify the presence of a key station or the central control apparatus for respective interrogation of each key station and for switching the state of the clock unit to receive or output data to the control apparatus on command.

Description

SPECIFICATION Electronic guard patrol systems The present invention relates to electronic guard patrol systems and more particularly to portable electronic clocks to be carried by a patrol guard and to central control and key points for co-operation with the electronic clock to produce and provide a record of the movements of a guard over a defined period.

According to the present invention there is provided an electronic guard patrol system including a plurality of key points, at least one portable electronic clock unit to be carried by a patrolling guard and a central control apparatus, in which each portable electronic clock unit includes a plurality of connection terminals for co-operation with corresponding connection terminals on each key station for electronically interrogating each key station, the connection terminals on the portable electronic clock unit also co-operating with connection terminals on the central control apparatus for transfer of information stored in the clock unit to the central control apparatus.

The portable electronic clock unit preferably includes means for detecting the central control apparatus and means for detecting the presence of a key station and for interrogation of each key station to record the identity of each key station visited in the electronic clock unit together with the time and date at which each respective key station was visited.

Preferably each portable electronic clock unit includes a real time clock which cooperates with the key stations to record the time and date of each visit by a patrol guard to each key station.

Embodiments of the present invention will now be described, by way of example with reference to the accompanying drawings, in which: Figure 1 shows in partial cross-section plan view a portable electronic clock according to the present invention; Figure 2 shows the portable electronic clock of Fig. 1 in cross-section along line A-A; Figure 3 shows the circuitry for the electronic clock of Figs. 1 and 2; and Figure 4 shows the co-operating circuitry of a key station to be visited.

With reference now to Figs. 1, 2 and 3, the clock unit 10 is a self-contained, micro-computer based, hand heid device intended for use as a data collection device for patrol guard security systems. It is intended that it be used in conjunction with multiple essentially passive wali mounted key units as shown in Fig. 4 and a single microprocessor based master control unit (not shown).The clock unit features in a practical embodiment: 8031 micro-computer 64K BITS of CMOS RAM for continuous data storage Real Time Clock to monitor date and time 8 NICad batteries (size AA) for operation and data storage Detection means for sensing presence of key or master control unit Low battery detection (prevents operation if nearly discharged, maintins data storage) Diode matrix for individual clock unit serializing Piezo-electric sounder Full duplex serial communications Interface via a six (6) way integral connection system Interface signals include supply IN/OUT -Ground sense (Key or Master) -Transmitted Data received Data transfer Clock (X 16) The interface signals are fed via terminals 12, 14, 16, 18, 20, 22 to respective terminals 42, 44, 46, 48, 50, 52 on the key unit 40 (Fig. 4) and into corresponding terminals on the master control central computer (not shown).

The clock unit 10 when not used is in the low power consumption standby state which provides maintenance power to the memory in the microprocessor control unit 55 and also to the real time clock 60. When a low resistance is detected across terminals 22 and 18, as will be the case when the clock unit is inserted into either a key station or a similar socket on the central computer, the circuitry then allows, battery state permitting the microprocessor control unit 55 to be fully activated. If the battery state is too low this powering up action is prevented by a battery sense circuit within sense circuit 51 in order to preserve the information already stored in the memory.

The microprocessor control unit will then proceed to enable the data storage RAM and switch on the power output circuit via switch 54 to power the external unit in case it is a key unit. The micro-computer also supplies a transfer clock (16 times the BAUD rate). Having waited a suitable settling time the microcontroller 55 will transmit a single character on line 49 (terminal 16). In response to this a key unit 40 will return its key number on line 53 (in the range 1 to 254) whilst a master controller will return a value of 0.

If the microprocessor unit 55 is accidentally activated then it will revert to the standby state if no signal is received during the limited period of time and the audible warning device will sound once only at the end of the period.

Thus it is not possible to run the rechargeable batteries down if for example the guard accidentally touches for example a metal object across the terminals 22 and 1 8.

If a clock unit is faulty then the audible warning device 56 will not sound. Thus it is possible to detect failure of either individual key stations or the clock unit.

The microprocessor control unit 55 then repeats this process for a limited period of time until several consecutive correct readings are received. The current date and time are accessed and stored together with the key station code number. Following this the microprocessor control unit and associated components are then powered down into the standby mode and during this powering down period the microprocessor control unit 55 delivers a signal to the audible warning device operating circuitry to sound the device twice.

If a good reading is not received then following the lapse of the limited period of time the microprocessor control unit commences its power down procedure but instructs the audible warning device to emit only a single sound thus indicating a faulty reading.

If the master controller central computer unit is detected (i.e. return value of 0), the clock will continue to monitor the serial input for instructions, allowing the master controller to dump and/or load data storage area, read/set the Real Time clock, identify clock unit by its factory set code or read/set any special security conditions stored by the clock (e.g. start-up character). When instructed to by the master controller the clock will switch itself off. If (dupe to a master controller error, etc.) the master controller goes silent for more than a few seconds, whilst the clock is still switched on, the clock will enter its failsafe mode and switch itself off. The master controller interface has access to the clock sense line so that it is not necessary for the clock to be removed from and re-inserted into the master controller if communications is required to be restarted.

The communication format will consist of control sequences for reading/setting single items of information (e.g. date, time, etc.) and utilising binary format for loading/dumping blocks of data.

Each clock 10 has a rechargeable battery 58 which is operative to maintain the real time clock 60 thus ensuring that the correct time and date is recorded against each key point entry.

Thus when the information stored in the clock is dumped into the computer unit this unit will be able to provide a read out of movements of a particular clock over for example a weekly or monthly period. Thus a complete record of patrol guard movements on a particular site over any period can be obtained.

The computer allows setting into each clock at the time of reading the clock an identification number comprising up to six letters or numbers using an ASS11 code giving unique identification of in excess of seven hundred thousand million individual clock codes.

Claims

1. An electronic guard patrol system including a plurality of key stations, at least one portable electronic clock unit to be carried by a patrolling guard and a central control apparatus in which each portable electronic clock unit includes a plurality of connection terminals for co-operation with corresponding connection terminals on each key station for electronically interrogating each key station, the connection terminals on the portable clock unit also co-operating with connection terminals on the central control apparatus for transfer of information stored in the clock to the central control apparatus.

2. An electronic guard patrol system as claimed in Claim 1, in which the portable electronic clock unit includes means for detecting the central control apparatus and means for detecting the presence of a key station and for interrogation of each key station to record the identity of each key station visited in the electronic clock unit, together with the time and date at which each respective key station is visited.

3. An electronic guard patrol system as claimed in Claim 2, in which each portable electronic clock unit includes a real time clock which co-operates with the key station to record the time and date of each visit by a patrol guard to each key station.

4. An electronic guard patrol system as claimed in any one of Claims 1 to 3. in which the electronic clock unit includes an audible warning device and circuit means for operating the audible warning device on receipt of a valid reading from a key station.

5. An electronic guard patrol system as claimed in any one of the preceding claims in which the portable electronic clock unit includes means for detecting the connection of the unit with a key station and means for supplying power to the key station to interrogate the identity of the key station and includes means for detecting the presence of a central control apparatus and means for switching the electronic circuitry of the clock unit to a state to receive instructions from the central control apparatus.

6. An electronic guard patrol system as claimed in Claim 5, in which the electronic clock unit includes means for detecting a low battery state and means for inhibiting the supply of power to a key station on detection of low battery voltage.

7. A portable electronic clock unit for the electronic guard patrol system of Claim 1, including a plurality of connection terminals for co-operation with corresponding connection terminals on each key station for electronically interrogating each key station, the connection terminals on the portable electronic clock unit also co-operating with connection terminals on the central control apparatus for transfer of information stored in the clock unit to the central control apparatus.

8. A portable electronic clock unit as claimed in Claim 7, including microprocessor and memory means for controlling the storage of information received from key stations or from the central control apparatus in the clock unit and including a real time clock to enable the date and the time of each recorded activity to be stored in the memory.

9. An electronic guard patrol system substantially as herein described with reference to the accompanying drawings.

10. A portable electronic clock unit substantially as herein described with reference to the accompanying drawings.