WO1996006414A1

WO1996006414A1 - Signalling system for electromechanical apparatus

Info

Publication number: WO1996006414A1
Application number: PCT/GB1995/001552
Authority: WO
Inventors: Andrew William Barson
Original assignee: Coin Controls Ltd.
Priority date: 1994-08-23
Filing date: 1995-07-03
Publication date: 1996-02-29
Also published as: GB9416995D0; AU2802295A

Abstract

Signalling of an operational parameter from an electrochemical apparatus, for instance a coin validator (4), is performed by operating an audible or visible electromechanical actuator, having another primary function. In the described examples, information about noise in sensing coils (3) is signalled by operating the accept gate relay (5) to produce a series of claps. The information may be received either by an operator counting the claps or, where coded signalling is employed, by means of a handheld receiver (7) which decodes the operational parameter information from the series of claps and displays a message.

Description

Signalling System for Electromechanical Apparatus

Field of the Invention

The present invention relates to an apparatus and method for signalling from ; an eleαromechanical apparatus.

Background of the Invention

It is a requirement of many systems that it be possible to obtain information about an operational parameter for maintenance or other reasons. One way 0 of providing for this requirement is for the system itself to include some form of display. However, this is often undesirable because of the cost of the display or because the location of the system makes the use of such a display impractical.

s As a result, systems have been developed where an electrical connection is made between a main unit and a handheld interrogating unit. These systems suffer from two disadvantages. Firstly, the main unit may need to be mounted in a location where it is difficult to make an electrical conneαion. Secondly, there are cases where the operational parameter of interest can be 0 affeαed by the aα of making an eleαrical conneαion. An example of this is the case where the operational parameter of interest is the level of noise in some part of the system.

It is an aim of the present invention to overcome the disadvantages of the S prior art.

Summary of the Invention

According to a first aspeα of the present invention, there is provided an eleαromechanical apparatus comprising control means , monitoring means to O determine an operational parameter of the apparatus, and an eleαromechanical aαuator, the control means producing a control signal according to a first criteria to operate the aαuator to perform a primary funαion, charaαerized in that the control means is arranged to be operable to produce said control signal according to an operational parameter, determined by the monitoring means, so as to operate the aαuator to perform a secondary, signalling funαion. The elαromechanical aαuator may be a relay, a stepper motor or the like

Preferably, the operation of the aαuator is audible. Thus, if a small amount of data is to be signalled, a service technician, for instance, can simply count the operations of the aαuator. This is reliable up to about twenty operations. However, the risk of miscounts increases greatly if there are more than twenty aαuator operations. More complex messages may be signalled by using a code such as Morse code. Although Morse code is based on combinations of long and short signal elements, early telegraph operators learnt to read Morse code transmissions from the rhythm of the relay used to control the marking pen.

The use of Morse code requires special training of staff. Consequently, apparatus according to the present invention preferably comprises a separate receiver where more complex messages are to be signalled. The preferred receiver includes a microphone, a processing circuit and a display means, wherein the processing means processes aαuator signalling deteαed by the microphone and drives the display to display a message in dependence on the aαuator signalling.

The receiver could be arranged to recognise Morse code and methods of doing this are well known in the field of radio communication. However, preferably, a code in which different symbols are represented by different periods between aαuator operations is used and the same number of symbols is used to represent each charaαer. A suitable code comprises four symbols, a first symbol represented by a first period, a second symbol represented by a second period twice the first period, a third symbol represented by a third period four times the first period and a fourth symbol represented by a fourth period eight time the first period. It will be appreciated that codes with different numbers of symbols could be used. Different combinations of the symbols can be used to represent different predetermined data items. For instance, the charaαers of the charaαer set known as ASCII, in which case j four symbols would be required for each charaαer. Thus, the charaαers of a message, e.g. ID 20101, can be represented by predetermined combinations of the symbols.

A suitable application for the present invention is in a coin validator. In o which case, the accept gate aαuator could be used to perform the signalling. Coin validators often employ induαive sensors to determine the validity and value of a coin. The coils used in such sensors are prone to eleαrical noise or eleαromagnetic interference (EMI) and it is important for support staff to know the level of this noise in the coils. However, as mentioned above, s measurement of noise can be affeαed by making eleαrical conneαions to an apparatus. Thus, the present invention is particularly suited to coin validators where the operational parameter of interest is the level of noise in the sense coils. However, the present invention could be used to signal other information. 0

Particular attention has been paid to the case where the aαuator is audible. However, if operation of the aαuator is visible, a technician could simply watch and count the operations of the aαuator.

S According to a second aspeα of the present invention, there is provided a method of signalling from an apparatus, comprising the steps of: determining an operational parameter of an eleαromechanical apparatus (16); operating an eleαromechanical aαuator (5), having a primary funαion other than signalling, in a controlled manner in dependence on the determined O operational parameter. Brief Description of the Drawings

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a block diagram of a first embodiment of the present invention; s Figure 2 is a block diagram of a second embodiment of the present invention; Figure 3 shows an operator using the second embodiment; and Figure 4 illustrates the signalling protocol used by the second embodiment.

Description of Preferred Embodiments w Referring to Figure 1, a coin validator comprises a controller 1 whose main funαion is to determine the validity and value of coins 2, sensed by four sensing coils 3 which are mounted in a unit 4 defining a coin path. Only one coil 3 is shown for the sake of clarity. The controller 1 includes a microcomputer, programmed to control the operation of the validator and is I/O devices. If the controller 1 determines that a coin 2 is valid, it outputs a signal to a relay 5. The relay 5 operates a coin accept gate in the unit 4 in response to these signals and the coin 2 emerges at B. If the coin 2 is not valid, the relay 5 is not operated and the coin emerges at A.

20 A switch 6 is also coupled to the controller 1. The microcomputer of the controller 1 is programmed to respond to operation of the switch 6 to put the validator in a diagnostic mode. In the diagnostic mode, the controller 1 outputs signals to operate the relay 5 in dependence on an operational parameter of the validator; in the present case the level of noise in the sensor coils 3. The operation of the relay 5 produces a clapping sound which can be heard outside of the cabinet, in which the validator is mounted.

The determination of the level of noise in the coils 3 will now be described.

O In the diagnostic mode, the controller 1 takes readings from each of the coils 3 repeatedly for 30 seconds. The maximum and minimum values for each coil 3 are stored. Thus, after 30 seconds the measured maxima and minima might be:

Coil 01 02 03 04

Max 47,54,43,50

Min 45,51,42,49

The controller 1 then determines the difference between the maximum and minimum for each coil 3. In the present example, this gives: 0

Diff 02,03,01,01

The controller 1 takes the largest of these difference values (i.e. 3) to be the measure of noise in the coils 3 and outputs three pulses to the relay 5. An s operator then hears three claps and can note that the noise level in the coils 3 is three.

A more sophisticated embodiment will now be described.

0 Referring to Figures 2 and 3, the coin validator includes the same main elements: a controller 1, sensing coils 3 and an accept gate relay 5, as in the first embodiment described above. However, the switch 6 is replaced by a rotary HEX switch 6a and a jumper 6b. The software controlling the system is also different. These differences will become apparent from the description s of the operation of the system below.

A handheld unit 7 is provided to deteα signalling claps from the relay 5 and display a message. The handheld unit 7 comprises a microphone 8, an amplifier 9 for amplifying the microphone output, a low-pass filter 10 coupled O to the output of the amplifier 9, a comparator 11 for producing a pulse signal from the signal output by the filter 10, a processor 12 arranged to receive the pulse signal from the comparator 11, an LCD display 13 driven by the processor 12 and a sounder 14 also driven by the processor 12.

As shown in Figure 3, the handheld unit 7 is conveniently housed in a gun- 5 shaped housing, having a pistol grip.

During normal mode operation, the controller 1 measures the noise in the sensing coils 3 at predetermined intervals and stores the most recent values. However, coin validation has priority. Therefore, when a coin 2 enters the o validator, the controller 1 handles the validation of the coin 2 before returning to its noise measuring routine. In this mode, the HEX switch 6a is used to seleα the tokens which the validator will accept.

The validator also has a diagnostic mode which is seleαed by inserting the s jumper 6b and then powering up the validator. In this diagnostic mode, the controller 1 deteαs any operation of the HEX switch 6a and initiates signalling in response thereto. During signalling, the controller 1 obtains the stored noise value and sends a corresponding pulse code to the relay 5 which then claps out the coded message. The controller 1 may also send further 0 pulse codes to the relay 5, representing additional operational parameters, for example percentage of coins rejeαed or an indication of a subsystem failure, e.g. an open circuit sensing coil.

The coin accept gate of the validator is able to open and close in about 20ms, s producing as it does so a single clap. The pulse code used by the controller 1 represents different symbols by different inter-pulse periods as shown in Table 1.

O Symbol Inter-Pulse Timing(ms)

Φo 320

*1 160

Φ: 80

*3 40

Table 1. Definition of code symbols.

As can be seen the symbols are represented by periods which are multiples of the shortest inter-pulse period, i.e. 40ms. Since the symbols are distinguished by ratios rather than absolute values, the handheld unit can be self-calibrating to take account of variations in components, temperature etc.

The messages signalled by the controller 1 make use of the ASCII charaαer set. Each of the 256 ASCII charaαers is represented by a predetermined combination of the four symbols. Of the 256 ASCII charaαers, 127 represent the letters of the alphabet, punαuation marks and certain control codes and 2 are reserved for start-of-message and end-of-message markers. The remaining 127 charaαers are undefined. The symbol combinations used to represent the ASCII charaαer set are shown in Table 2.

Symbol Combination ASCII Charaαers

Φ_{0 0 0 0} to Φ₀ΦιΦ₂Φ₂ 27 combinations undefined

Φ₀Φ,Φ₂Φ₃ start-of-message

Φ₀Φ,Φ₃Φ₀ to Φ_JΦ_JΦ_JΦ_J 100 combinations undefined

Φ₂Φ₀Φ₀Φ₀ to Φ₂Φ,Φ₃Φ₃ ASCII 000 to 031 : control codes

Φ₂Φ₂Φ₀Φ₀ to Φ₃Φ₃Φ₃Φ₂ ASCπ 032 to 126 : space to " ~ " Φ₃Φ₃Φ₃Φ₃ end-of-message

Table 2. Symbol combinations for ASCII charaαer set.

Each message signalled by the controller 1 has the following form:

start-of-message : message : end-of-message : checksum

The message itself may comprise one or more groups of symbols. The 0 checksum is represented by an appropriate combination of symbols, e.g. Φ₀Φ₀Φ₀Φ₀ (checksum - 0) to Φ₃Φ₃Φ₃Φ₃ (checksum - 255).

The following message is illustrative of the message format employed by the present embodiment: s

Φ₀Φ,Φ₂Φ₃ start-of-message

Φ₃Φ₀Φ₃Φ₀ "L"

Φ₃Φ₀Φ₃Φ₃ "O"

Φ₃Φ₃Φ₃Φ₃ end-of-message

$1*3*1*0 checksum - 116 decimal

S The pulse sequence for this explanatory message is illustrated in Figure 4. It should be noted that the number of pulses required is one more than the number of symbols because an end pulse is required to define the end of the last symbol.

O The operation of the handheld unit will now be described. When a message is to be signalled by the controller 1 of the validator, an operator 15 points the handheld unit 7 at the validator. In the present case, the validator is in a typical installation in a vending machine 16. The microphone 8 deteαs each clap from the accept gate of the validator and outputs a complex waveform containing high and low frequencies. The amplifier 9 amplifies this complex waveform and applies it to the filter 10. The filter 10 is arranged such that the complex waveform is transformed into a single pule. The comparator 11 converts the pulse from the filter 10 into a substantially square pulse, suitable for processing by the processor 12. Thus, a series of claps produced by the accept gate are represented at the input to the processor 12 as a train of square pulses (see Figure 4).

The processor 11 is initially in a staπ of message deteαion and self-calibration mode wherein it performs the following algorithm:

Step 1 wait for first pulse (pulse 1) start timing tO wait for second pulse (pulse 2) stop timing tO and save time as TO calculate t «- TO / 32 where 32 is a tolerance faαor calculate wl - (TO / 2) - 1 calculate w2 - (TO / 2) + t

Step 2 start timing 11 wait for third pulse (pulse 3) stop timing tl if (tl < wl) or (tl > w2) then error : restart save tl as Tl calculate wl - (Tl / 2) - 1 calculate w2 - (Tl / 2) + t Step 3 start timing t2 wait for fourth pulse (pulse 4) stop timing t2 s if (t2 < wl) or (t2 > w2) then error : restart save t2 as T2 calculate wl - (T2 / 2) - 1 calculate w2 - fT2 / 2) + t

0 Step 4 start timing t3 wait for fifth pulse (pulse 5) stop timing t3 if (t3 < wl) or (t3 > w2) then error : restart s save t3 as T3

Dividing by 32 is easy to do on most low-cost microcontrollers as it merely involve right-shifting a number by five places. Likewise, dividing by 2 merely involves right-shifting a number by one place. 0

This algorithm checks for a valid start-of-message marker (t3 - ^lAt2, x.2 - Vitl, tl - VitO) and stores the periods for the symbols (Tl, T2, T3, T4) for future comparison with incoming pulse gaps. The tolerance faαor for a valid symbol is defined as ± TO / 32. If a pulse gap does not lie within this S tolerance on TO, Tl, T2, or T3 then the symbol is invalid and the start-of- message marker deteαion and self-calibration routine is returned to after a short delay. As can be seen, the absolute timing of pulses is not the most important faαor as the symbol identification relies primarily on the ratios of the inter-pulse periods. O

Once TO, Tl, T2 and T3 have been established by the processor 11, further charaαers are determined by measuring the inter-pulse timing for groups of five pulses and accessing a look up table on the basis of the symbol combinations. When the processor 11 deteαs an end-of-message marker, it interprets the next charaαer as a checksum and then returns to the start-of- message marker deteαion and self-calibration routine. s

The undefined symbol combinations may be used as message tokens to indicate certain standard events, e.g. Φ₀Φ₀Φ₀Φ₀ coin validator operating correαly Φ₀Φ₀Φ₀Φ. fault deteαed in induαive sensors o Φ₀Φ₀Φ₀Φ₂ more than 10 strimming frauds deteαed Φ₀Φ₀Φ₀Φ₃ more than 10 lead slugs deteαed

If the checksum indicates that a valid message has been received the processor 12 applies the appropriate message to the display 13. However, if the s checksum indicates that the message has been corrupted, the processor 12 returns to the wait for start of message and self-calibration routine.

Once the processor 12 has determined that a valid message has been received, it operates the sounder 14 to alert an operator that a message is being 0 displayed on the display 13.

The processor 12 is provided with some form of non-volatile storage, for example RAM with a continuous power supply, and all received messages are stored there so that they may be transferred to a computer or redisplayed, in s case the operator 15 missed a message when it was displayed on reception.

The claps from the acceptor gate may be transmitted by telephone to a central station. The claps could then be interpreted at the central station either by ear or a device similar to the handheld unit described above, such a unit need O not be handheld. In the second embodiment, the handheld unit 7 responds solely to coded signalling. However, the unit could be provided with a switch to seleα between a mode where coded signalling is processed to a mode where the processor merely counts deteαed claps. A simplified handheld unit, employing a counter with a simple 7-segment LED display could be used with the first embodiment.

Claims

1. An eleαromechanical apparatus comprising control means (1), monitoring means (1) to determine an operational parameter of the apparatus, s and an eleαromechanical aαuator (5), the control means producing a control signal according to a first criteria to operate the aαuator to perform a primary funαion, characterized in that the control means is arranged to be operable to produce said control signal according to an operational parameter, determined by the monitoring means, so as to operate the aαuator to perform o a secondary, signalling funαion.

2. An apparatus according to claim 1, wherein the operation of the aαuator is audible.

3. An apparatus according to claim 1 or 2, wherein the primary funαion of the aαuator is to drive an accept gate (5) of a coin validator (4).

4. An apparatus according to claim 1, 2 or 3, wherein the monitoring means deteαs the level of noise in a coil (3) of induαive sensing means of a coin validator (4).

5. An apparatus according to any preceding claim, wherein the control means is arranged to produce the control signal for signalling so as to signal data concerning the operational parameter according to a code in which different symbols are represented by different periods between aαuator operations.

6. An apparatus according to claim 5, wherein the code comprises four symbols, a first symbol represented by a first period, a second symbol represented by a second period twice the first period, a third symbol represented by a third period four times the first period and a fourth symbol represented by a fourth period eight time the first period.

7. An apparatus according to claim 6, wherein charaαers of a message are represented by predetermined combinations of said symbols.

8. An apparatus according to claim 7, wherein four symbols are used to j represent each said charaαer.

9. An apparatus according to claims 2, comprising a separate receiver (7), the receiver including a microphone (8), a processing circuit (9,10,11,12) and a display means (13), wherein the processing means processes aαuator signalling 0 deteαed by the microphone and drives the display to display a message in dependence on the aαuator signalling.

10. An apparatus according to claim 1, wherein operation of the aαuator is visible.

11. A method of signalling from an apparatus, comprising the steps of: determining an operational parameter of an eleαromechanical apparatus (16); operating an eleαromechanical aαuator (5), having a primary funαion other than signalling, in a controlled manner in dependence on the determined operational parameter.

12. A method according to claim 11, wherein the aαuator is audible.

13. A method according to claim 12, wherein the aαuator is visible.

14. A method according to claim 11, 12 or 13, wherein said signalling employs a code in which different symbols are represented by different periods between aαuator operations.

15. A method according to claim 14, wherein the code comprises four symbols, a first symbol represented by a first period, a second symbol represented by a second period twice the first period, a third symbol represented by a third period four times the first period and a fourth symbol represented by a fourth period eight time the first period.

16. A method according to claim 15, wherein charaαers of a message are represented by predetermined combinations of said symbols.

17. An apparatus according to claim 16, wherein four symbols are used to represent each said charaαer.