GB2304938A

GB2304938A - Master and one by one slave synchronisation

Info

Publication number: GB2304938A
Application number: GB9518374A
Authority: GB
Inventors: Cheuk Fai Ho; Kenneth Fu Kuen Sin
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-09-06
Filing date: 1995-09-06
Publication date: 1997-03-26
Also published as: GB9518374D0

Abstract

A master clock 10 is provided to synchronise the real time clocks in individual devices such as computer terminals recording devices, and time clocks. The master clock 10 incorporates a processor and a real time clock and is connected to each of the individual electrical devices in turn. This connection is by way of a cable 13 and a connector 14, or may be a wireless connection. A transmission signal switch 16 is then operated to cause the processor to output a time signal, and the device is synchronised by the time signal to the time determined by the master clock. The time as determined by the master clock is displayed by display 15. The individual device connected to the master generates a return confirmation signal when synchronisation has been effected, which is stored in the master, and receipt of the confirmation signal illuminates a confirmation signal light 17.

Description

IMPROVEMENTS IN OR RELATING TO THE REGULATION OF CLOCKS The present invention relates to a method of controlling clocks in a number of individual devices using a regulating apparatus, and to regulating apparatus for this purpose.

More and more electrical devices are provided with real time clocks. For example, in some devices the clocks enable the time at which events occur to be determined and/or recorded.

There is a need to synchronize the real time clocks provided in individual devices in the same environment.

This is particularly the case if the individual devices are being used in cooperation to monitor events in an enterprise and/or to control an operation. Traditionally, such clocks are synchronised manually, and this can be time consuming for the operator concerned, and it is difficult for the synchronisation to be accurate.

According to a first aspect of the present invention there is provided a method of controlling clocks in a number of individual devices using a regulating apparatus having clock means serving as a master clock, the method comprising the steps of signalling to the clock(s) in each individual device the time determined by the master clock, and causing each of said clocks to be synchronised to the signalled time.

As the clock or clocks in each individual device is synchronised to the time signalled from the regulating apparatus, it will be appreciated that with an embodiment of the method of the invention, it is straightforward to synchronise the clocks of a number of individual devices with the master clock of the regulating apparatus.

Preferably, to enable the clocks to be synchronised, the method further comprises the steps of coupling the regulating apparatus to each said individual device and then undertaking the signalling and synchronisation steps.

Preferably, the regulating apparatus is coupled to each individual device in turn.

In a preferred embodiment, each said individual device is arranged to generate a confirmation signal upon completion of the synchronisation of a clock thereof in response to a time determined signal from said regulating apparatus.

In an embodiment, the method further comprises the step of causing the regulating apparatus to indicate the receipt of a confirmation signal.

If required, the method may further comprise the step of storing confirmation signals in the regulating apparatus.

According to a further aspect of the present invention there is provided a regulating apparatus for use in a method as defined above.

The present invention also extends to a regulating apparatus for controlling clocks in individual devices, said regulating apparatus comprising clock means serving as a master clock, and time signal generating means for generating and outputting a time signal representative of the time determined by the master clock.

In an embodiment, said regulating apparatus further comprises coupling means to couple said regulating apparatus to an individual device to enable the time signal output by said time signal generating means to cause a clock of the individual device to be synchronised to the time determined by the master clock.

The coupling between the regulating apparatus and each individual device may be by way of a link, for example, an infrared, inductive, or other communications link which does not require a physical connection.

Alternatively, said coupling means may comprise a physical connector for connecting said regulating apparatus to each individual device.

In a preferred embodiment, said time signal generating means is provided by processor means of the regulating apparatus.

Preferably, said regulating apparatus is provided with a display for displaying the time determined by said master clock.

Additionally and/or alternatively, the regulating apparatus may be provided with indicator means enabled to indicate when a clock of an individual device has been synchronised to the master clock.

Embodiments of the present invention will hereinafter be described, by way of example, with reference to the accompanying drawing which shows schematically a regulating apparatus of the invention.

The figure shows a regulating apparatus which may be used to synchronise the real time clocks in a number of individual devices (not shown). These individual devices may be any devices which incorporate real time clocks. For example, the individual devices may be computer terminals, recording devices, time recording apparatus, and any other electrical apparatus. If all of the apparatus are within a single environment, for example, in an office or in a factory, it is advantageous for the clocks of all of the devices to be synchronised. Such synchronisation is essential if any of the clocks are used in a first individual device employed in a control or monitoring function in cooperation with a further individual device having its own clock.

The regulating apparatus shown in the figure is generally referenced 10 and incorporates a processor (not shown) and a real time clock (not shown). The regulating apparatus 10 is arranged to be appropriately connected to each of a number of individual electrical devices (not shown) in turn. In the embodiment illustrated, this connection is by way of a cable 13 and a connector 14. It will be seen that the connector 14 is a substantially conventional RS232 male connector. Of course, where a physical connector is to be provided, this may be of any appropriate type.

Alternatively, the regulating apparatus 10 may be arranged to be coupled to each individual device, for example, by a communications link which may be infrared, or inductive, or employ any other appropriate communication means. It is, however, preferred that the connector coupling enables two way communication between the regulating apparatus and the individual device.

In use, the regulating device 10 is connected to a number of individual devices in turn. When the regulating apparatus 10 is connected to such an individual device, a transmission signal switch 16 is operated to cause the processor to output a time signal representative of the time as determined by the master clock. This time signal is applied to the individual device. The real time clock of the individual device connected to the regulating apparatus 10 is arranged to be synchronised by the time signal to the time determined by the master clock.

Preferably, and as illustrated, the regulating apparatus has a display 15 on which may be displayed the time as determined by the master clock. It is preferred that the time determined, which is output as a time signal by the processor constituting the time signal generating means is displayed on the display 15.

Preferably, the individual device, which is in communication with the regulating apparatus, is arranged to confirm that it has adjusted its real time clock in dependence upon the time signal applied thereto by the regulating apparatus 10. In this case, each individual device may be arranged to generate a confirmation signal.

Receipt of the confirmation signal by the regulating apparatus 10 may be signalled by way of a confirmation signal light 17.

During use, the time determined by the master clock of the regulating apparatus 10 is preferably displayed in the display 15. When it is required to synchronise the real time clock of a number of individual devices, the regulating apparatus 10 is coupled to each apparatus in turn. The clock or clocks of the individual device may then be synchronised with the regulating apparatus 10 as described. Thereafter, the regulating apparatus 10 is disconnected from that individual device and reconnected to another device whereby the clocks of the other individual device may be synchronised with the master clock in a similar manner. It will be appreciated that if the clocks of a number of devices are so synchronised, the clocks of all of the individual devices will be similarly synchronised with each other.

It will be appreciated that variations and modifications may be made to the invention as described and illustrated within the scope of this application.

Claims

1. A method of controlling clocks in a number of individual devices using a regulating apparatus having clock means serving as a master clock, the method comprising the steps of signalling to the clock(s) in each individual device the time determined by the master clock, and causing each of said clocks to be synchronised to the signalled time.

2. A method of controlling clocks as claimed in Claim 1, further comprising the steps of coupling the regulating apparatus to each said individual device and then undertaking the signalling and synchronisation steps.

3. A method of controlling clocks as claimed in Claim 2, wherein the regulating apparatus is coupled to each individual device in turn.

4. A method of controlling clocks as claimed in any preceding claim, wherein each said individual device is arranged to generate a confirmation signal upon completion of the synchronisation of a clock thereof in response to a time determined signal from said regulating apparatus.

5. A method of controlling clocks as claimed in Claim 4, further comprising the step of causing the regulating apparatus to indicate the receipt of a confirmation signal.

6. A method of controlling clocks as claimed in Claim 4 or Claim 5, further comprising the step of storing confirmation signals in the regulating apparatus.

7. Regulating apparatus for controlling clocks in individual devices when arranged for use in a method as claimed in any preceding claim.

8. A regulating apparatus for controlling clocks in individual devices, said regulating apparatus comprising clock means serving as a master clock, and time signal generating means for generating and outputting a time signal representative of the time determined by the master clock.

9. Regulating apparatus as claimed in Claim 8, further comprising coupling means to couple said regulating apparatus to an individual device to enable the time signal output by said time signal generating means to cause a clock of the individual device to be synchronised to the time determined by the master clock.

10. Regulating apparatus as claimed in Claim 9, wherein said coupling means comprises a communications link which does not require a physical connection.

11. Regulating apparatus as claimed in Claim 9, wherein said coupling means comprises a physical connector for connecting said regulating apparatus to each individual device.

12. Regulating apparatus as claimed in any of Claims 8 to 11, wherein said time signal generating means is provided by processor means of the regulating apparatus.

13. Regulating apparatus as claimed in any of Claims 8 to 12, wherein said regulating apparatus is provided with a display for displaying the time determined by said master clock.

14. Regulating apparatus as claimed in any of Claims 8 to 13, further comprising indicator means enabled to indicate when a clock of an individual device has been synchronised to the master clock.

15. A method of controlling clocks in a number of individual devices substantially as hereinbefore described with reference to the accompanying drawing.

16. Regulating apparatus for controlling clocks in a number of individual devices substantially as hereinbefore described with reference to the accompanying drawing.