GB2200779A

GB2200779A - Electronic control systems

Info

Publication number: GB2200779A
Application number: GB08728270A
Authority: GB
Inventors: Richard Neil Osborne
Original assignee: * JPM; JPM
Current assignee: * JPM; JPM
Priority date: 1986-12-03
Filing date: 1987-12-03
Publication date: 1988-08-10
Also published as: GB8628940D0; GB8728270D0

Abstract

The reels of a fruit machine are driven by stepper motors (8, 9, 10) and produce cyclic pulses for checking their rotation. A microprocessor (1) control writes instructions to a main shift register (4) and these are transferred on clock (3) triggering to subsidiary shift registers (5, 6, 7) connected in series, each register being associated with a respective stepper motor/reel. The latter operate in accordance with the instructions in their associated subsidiary shift register, and those registers in turn receive the rotational pulses, which are subsequently fed back to the microprocessor. The invention is applicable to other groups of electrical devices operating in parallel, enabling the control to be applied economically in serial form. <IMAGE>

Description

"Improvemen't's'rel'ating'to :EIectrOnic Control Systems11 This invention relates to electronic control systems and is concerned with governing a plurality of parallel operating devices each in an individual manner.

It has been primarily developed for gaming or amusementwith-prizes machines, known as fruit machines, in which a number of reels, usually three or four, are set to rotate and then stop in a random or quasi-random manner.

It is now conventional practice to rotate the reels by means of associated stepper motors, a separate one for each reel. It is also common to have lights associated with the windows in which the reel symbols show. Usually there are three symbols visible in each window, and so there are three related lights, any one of which may be energised to distinguish one of the symbols from the others.

Another reel-asso'ciated signal (but one from the reel to the control means) indicates the reel's position.

Normally it is sufficient to have just one datum point on the reel generating a pulse in an adjacent sensor each cycle, and this is fed back as a check to a central processor unit. The stepper motor pulses can be relied upon to determine the reel position through the rest of the reel cycle.

Thus, for each reel and its associated lights and position sensor there will be eight control wires (excluding power supply wires) from the central processor unit, four for the stepper motor, three for the lights, and one for the position. With just three reels, each requiring its own set of. wires, this mounts up to twenty four separate wires. All this is costly in material and, in particular, manufacturing and assembly time.

It is the aim of this invention substantially to reduce this bundle ofwires while still maintaining reliable and accurate control over the reels or other devices.

According to the present invention there is provided a control system for a plurality of paralleloperating electrical devices comprising a central processor adapted to write into a main shift register control information for said devices, a plurality of subsidiary shift registers associated with respective devices and series-connected, and clock means for triggering transfer of the contents of the main shift register to the subsidiary shift registers, each then having independent control information for the respective device, and for implementing such control.

The central processor will conveniently be arranged to write the control information into a parallel register, and from there it is transferred to the main shift register by a timing control forming part of the clock means.

Each device may be arranged to produce feedback information on its condition, in which case the clock means can be arranged to insert such information into the control information shifted back to the central processor.

In the form to which we are most likely to apply this system the devices will be reels of a fruit machine, stepper motor operated. There will be selectively illuminated bulbs associated with them, and at least one datum point on each reel giving cyclic pulses.

For a better understanding of the invention one embodiment will now be described, by way of example, with reference to the accompanying drawing, in which the single figure is a simplified diagram of a control system for the reels of a fruit machine.

The system has a central microprocessor 1 which writes a pattern for a set of stepper motors and lamps to a parallel holding register 2. A timing control 3 periodically causes this information to be transferred to a shift register 4 where it is loaded in parallel form. The output of the shift register 4 is to the first of a set of subsidiary shift registers 5, 6 and 7 linked in series and physically quite remote from the elements 1 to 4. These shift registers govern respective stepper motors 8, 9 and 10 which independently drive reels (not shown) and energise lights 11, 12 and 13. The shift registers 5, 6 and 7 have a common clock input, indicated by 14, synchronised with the timing control 3. The output of the final shift register 7 is back to the main shift register 4.

Each pattern written into the shift register 4 is shifted out serially into the registers 5, 6 and 7 where it is distributed so that each of the latter has a pattern assigned to its reel alone. When this transfer is complete, the subsidiary registers are clocked to cause their patterns to be impressed on the associated stepper motor coils and reel lamps. Each reel is moved accordingly and the lamps are illuminated or not, as instructed.

At the same time the reel datum position information is clocked in.

When this is complete the datum position information is directed back to the main shift register 4 by the same serial method where it can be accessed to determine the reel positions. At the same time a new pattern for the stepper motors and lamps will be shifted to the reels.

It will be appreciated that, with this system, the number of wires between the central processor unit and the reels is drastically reduced, and that further reels (or other devices in different applications) can be added without increasing that number. Expansion is also simplified and made cost effective as the drive electronics are associated with the reels and do not need to be provided on the control electronics. The identification of each reel is made automatically by the position of its related shift register in the chain, and thus there is no need to define an address by which each reel can be selected. All reel units can therefore be identical.

Claims

1. A control system for a plurality of paralleloperating electrical devices comprising a central processor adapted to write into a main shift register control information for said devices, a plurality of subsidiary shift registers associated with respective devices and series connected, and clock means for triggering transfer of the contents of the main shift register to the subsidiary shift registers, each then having independent control information for the respective device, and for implementing such control.

2. A control system as claimed in Claim 1, wherein the central processor has a parallel register, and the clock means transfers information therein to a main shift register at each cycle.

3. A control system as claimed in Claim 1 or 2, wherein each device is arranged to produce feedback information on its condition and the clock means is arranged to insert such information into control information shifted back to the central processor.

4. A control system as claimed in Claim 1, 2 or 3, wherein said devices are fruit machine reels, stepper motor driven.

5. A control system as claimed in Claim 4, wherein there are 'illuminating means associated with the reels, selectively energisable from control information in the associated subsidiary shift register.

6. A control system as claimed in Claim 4 or 5, as appendent to Claim 3, wherein the reels each provide cyclic pulses for insertion as said feedback information.