IE51965B1 - Micro-processor controlled coin-box telephone instruments - Google Patents

Description

Uith the advent of micro-processor controlled coin-operated telephone instruments (or payphones) the facilities provided to the users of such instruments have been substantially expanded. The payphone instrument may be operated by the telephone authority and therefore these instruments are located in public places or may be rented to private concerns with the instrument being used by a large number of individuals using the premises of those concerned. In all cases it is important*to ensure that the design of the payphone does not put constraints upon its location. One major feature of such payphone instrument is that it should be powered from the telephone line (using an internal battery charged from line current). While the power consumption of micro-electronic circuitry is by and large not very high it is still important to ensure that the power consumption is kept to a minimum.

It is an aim of the present invention to provide a payphone instrument whioh is very economical on line power. According to the invention there is provided a coin-operated telephone instrument including means for monitoring for i nftnm-i.ng calls and means for handling - 3 incoming calls and outgoing calls wherein the means for handling incoming calls and means for handling outgoing calls are adapted to he powered-down when the telephone is idle and are arranged to be selectively powered-up as required when the instrument is taken into use.

Typically the instrument is micro-processor controlled and remains in the powered down state until one of a number of input events occurs as a result of (a) an automatically generated call to report a fault or a cash-box full condition, (b) an incoming call is detected, (c) a normal outgoing call is commenced or (d) sn insulate line test condition is detected.

In addition the payphone instrument includes a line interface equipment which includes line length assessment arrangements which may be adapted to control the amplification level of the speech amplifiers of the instrument.

The invention will be more readily understood from the following description which should be read in conjunction with the accompanying drawings. Of the drawings:?ig. 1 shows a block diagram of the equipment required for one embodiment of the invention, Jig. 2 shows a typical flow chart of a section of the program, while Tig. 3 shows a diagram of the work space memory map.

The telephone instrument described, herein is of a new prepayment type specifically designed to accept four U.K. coin denominations through a single slot with optical and electronic sensors to identify, validate and count the coins. Microprocessor control is employed, enabling coins to be inserted during conversation and credited to the caller. Coins are not collected until the end of the call, when the total fee is evaluated and any surplus coins are refunded as change.

The payphone requires to be of rugged construction to withstand vandalism and theft in public places. It includes facilities such as automatic transmission to the accounting centre giving the value of the cash box contents when this is exchanged for an empty one. The payphone, a detailed description of which is given later, incorporates An advanced design of electronic coin validator, Modular software, control of the operational functions, A single coin entry slot for all coin denominations, A visual display showing the stored credit and when to insert coins, A means of returning rejected coins to the user, Best change facility, A follow on call facility, A rubbish flushing mechaniam, A lockable cash box with a shuttered coin slot to prevent unauthorised coin removal, A keypad highly resistant to mechanical damage, 51865 - 5 Choice of Decadic or M54- signalling, A software controlled fully flexible call charging system, Means to re-programme to accommodate changed tariffs, Automatic fault reporting, Powering from the line, Ease of installation and maintenance, Bugged case design.

OtimiHE HESCBUTIOH OB THE PAEEBOHE SOFTWARE System Organisation Electrically, the system is electronic, employing a fully electronic validation process coupled with a centralised microprocessor control. The system organisation, will be better understood by reference to the accompanying schematic diagram shown in Pig. 1. The schematic diagram shows how the electronics of the payphone is partitioned into interface circuitry IA validator and coin management control circuitry VCMA, a micro-processor control MFC, analogue and line interface circuitry ATTA and a keypad/ display K/D.

The interface circuitry IA serves the equipment and device used to detect, validate and control the passage of coins in the runway of the payphone equipment. The devices used comprise (i) a coin entry sensor CES, (ii) two sets of validator coils VC'’ and VC2 with a coin passage sensor CVS, (iii) a false operation or coin held sensor CHS and (iv) coin arrangement equipment involving a coin store sensor CISS and three electric magnets EM1, S1965 - 6 EM2 and EM5 wiiich control the passage of coins into and out of the coin store.

The validator and coin management control circuitry VCMA consists of circuitry which is used to drive the interface circuitry IA from the micro-processor MFC and to ffnrnimim' cate information to the micro-processor MFC from the interface circuitry IA. The equipment used in VCMA comprises (i) a coin entry sensor driver CESD and a coin entry sensor receiver GESB, (ii) coin validator circuitry CV, (iii) a coin heli sensor drives CHSD and a coin held sensor receiver CHSB, (iv) an accept coin electromagnet driver ACT, (v) a coin ia store sensor driver CISD and a coin in store receiver CISB and (vi) a cash/refund electromagnet driver C/DD.

The analogue and line interface circuitry AHA provides various equipment for use ia administering telephone linerelated functions. The functions performed hy this equipment are (a) the administration of the audio route, (b) a telephone line interface allowing signals to be injected into the·telephone line and signals on the telephone line to be recognised by the payphone, . (c) a line switching unit allowing the payphone to handle telephone calls, (d) a multi-frequency/Loop disconnect signalling unit allowing either m-f signalling or dial-impulse signalling to be provided to the line when setting up outgoing calls (e) a ringing current detector for detecting ringing current when an incoming call is made to the payphone (f) a line insulation test detector »1865 “ 7 arranged to detect that the line insulation for the telephone line connected to the payphone is being tested at the exchange, and (g) a battery regulator. Interfacing to the analogue and line interface circuitry are a number of discrete components which are either external signal generating devices or the like. Typically these components are (i) the line terminal block ITB, (ii) the telephone handset H/S, (iii) the handset switch HSS, (iv) a charge pulse detector CPU, (v) a call follow on button JOB, (vi) an audiable incoming call indicator AICI and (vii) the battery BAI.

The keypad and display K/P provides the interface into the micro-processor for these functions allowing a caller to key up the required number which is then passed by the micro-processor to the dial signalling unit in the analogue and line interface circuitry AILA. The display is used to provide information to the user on the progress of a call including for example the remaining credit available.

The micro-processor MPC is used to control and coordinate the entire activities of the pay phone and it will be appreciated that the micro-processor is effectively . at the centre of a star network with bus connections B1, B2, B5 and B4 to points of the network where the validator and coin management control circuitry VCMA, the analogue and line interface circuitry AICA and the keypad/display K/D are positioned. Because of this construction the micro-processor MED is in a position to control the S1S65 - 8 activation and de-activation of all on pants of the payphone. Typically each individual equipment within the points of the star network is provided with a power-on switch which is controlled hy the micro-processor so that when the corresponding equipment is not in use the microprocessor may power-down that part of the payphone to concerve upon the energy.drain from the battery BAT which is line - charge-powered only. In Big. 1 leads CESVO, VB, TONS, CHDVO and CISTO indicate voltage on/off control leads which are used under micro-processor control to regulate the powering-on or off of the corresponding equipments. Similarly some·of the functions controlled by the analogue and line interface circuitry AHA can be powered down when the payphone is idle. Bor example, the audio amplifiers in the audio route can be powered-off as can the dial signalling unit and some of the line switching functions. Similarly the charge-pulse-detection equipment GED, and the audible incoming call indicator can be powered down. However, the line interface equipment and the handset switch detection equipment requires to be powered-up at all times.

When the telephone is not being used as mentioned above all logic circuits are powered down, except for a small section of monitoring circuitry and the CMOS memories which provide the long term data store. Various events vail automatically switch the system power on:1. Handset removed from the hookswitch. 2. An incoming call detected.

S1965 ” 9 3· A request for an automatic fault report from the monitoring circuitry.

When the CHJ has started processing after power up it will check which ’power up' event has oooured and carry out the necessary actions.

The CMOS memory mentioned above will hold all cash totals (records) and all charging parameters and free call numbers which are programmed via the external programming unit into leads EE. The ON hook charging switch takes its base current directly from the line, and a bias resistance (1 Meg Cbm) will appear across the line during any insulation tests. Erotection against line transients is accomplished by the use of two gas discharge surge arresters and a resistor - zener combination. The batteries used are Nickel - Cadmium with a capacity of 500 mA.H so that the maximum charging current that will be experienced when the payphone is situated close to the exchange will not exceed the rated continuous charge current of the batteries.

BgtHDBB OEEBATION - COIN ΕΝΤΒΓ Coin entry is made via a single slot for all coin denominations of the four coin set. Provision may be made later for any antic'ipated extension to the coin set range or introduction of a completely new coin set.

VALIDATION EBQCESS Coins subjected to the validation process pass along a coin runway and their location relative to the validator are detected by opto-electronic sensors (designated sensors 5i96S - 10 CES and CVS in Pig. 1). Validated coins may only pass into the coin store through coin diversion arrangements responsive to the operation of electromagnet EOT. Nonoperation. of electromagnet EOT will result in the coins being directed to a refund channel. Under the validation process two inter-related tests are made on each coin.

The first test provides a measurement which gives an indication of the general bulk and alloy characteristics of the coin whilst the second test provides a relatively precision measurement indicative of the value of the coin. The concept- of the validation teste provides for apparatus temperature variations over the specified range. Coins failing the validation process are immediately refunded by the non-operation of electromagnet EOT. It is noteworthy that most conceivable circuit or component malfunctions will result in the immediate refund of any coins inserted. Validated coins diverted into the coin store are retained against the subsequent determination process of encashment or refund unless the coin store becomes full in which case, the coin at the front of the queue will be cashed if, when a further coin is inserted, credit to the value of the coin has been used during the call.

COIN MANAGEMENT On termination of a call, by returning the handset to its rest, the payphone calculates which coins to accept and which to refund (from their value and relative position) in order to give best change to the user. The cashed coins - 11 are assigned a weighted value according to their size and these values are added to an accumulative total (of all previous calls) held in memory and it is this accumulative total which gives- an indication of the cash container 75% Full and 100% Full. It is this information which forms part of the Fault Beporting Message. The monetary value of the encashed coins is also added to an accumulative cash cointainer contents total (this too is held in memory) and it is this accumulative total which ia sent to the appropriate accounting centre on removal of the cash container. Opto sensor CI55 is strategically positioned so that it monitors - the first position in the coin store and detects the presence of a coin. It is used to immobilize the payphone from further chargeable calls, in the event of a malfunction which prevents the payphone from either cashing or refunding coins. For example, electromagnet failure or coin jamming.

A further sensor is provided (Sensor CH5) which prevents coin manipulation by means of string or the like within the payphone.

The remainder of the operation of the payphone involves the user in using the keyboard to originate outgoing calls which are controlled by the micro-processor software.

The software is structured into a series of modules, sub-routines and interrupts for ease of programming.

Typically these modules and sub-routines are:51965 - 12 Power-on restart, Main, Background, Line Interface, Tones, Keyboard Interrogate, Display Service, Escrow Interrogate, Timer Service, Coin Acceptor, Charge Handler, End of Call, Power end and Auto Call. Pig. 2 shows the software structure and will he considered later as far as its execution is concerned.

Special sub-routines are provided for (i) cashing a single coin off the escrow, (ii) converting any three bit byte hi nary number into hi na-ny coded decimal, (iii) putting an erent from the accumulator into the input stack, and (iv) handiing the interrupt routine.

The programm modules are provided in order of. priority and a frequency of service in milliseconds as shown in the following table.

IETEBEDPIS OBDEB OP ΡΒΙΟΒΙΤΪ PEEQUEMCI OP SEBVICE Line Interface 52 ms Coin Acceptor 8 ms Escrow 16 ms 20 Tones 128 ms Bestswitch 52 ms Charge Handler 64 ms Timers 64 ms Keyboard 52 ms 25 Display 256 ms The software is organi gad to operate upon input and output events and these are listed as follows:51965 OUTPUT EVENTS HE! 01 02 CONNECT rare DISCONNECT LINE POR 1.25s LENE 03 04 05 06 10 11 DISCONNECT LINE POE 12.5s DISC. LIKE SIART/CONTINUE DIALLING AUDIO OPT CLEAR DIKED START PEEE/OP CALL TEST keyboard 12 14 20 21 22 KEYBOARD OPT KEXBQARD ON DISPLAT OPT DISPLAI PLASH 00.00 DISPLAT CREDIT DISPEAT 23 24 25 26 30 INSERT MONET OK 999 call onlt car DISPLAT CASHBOZ CONTENTS (£) TEXTS OPT COUT ACCEPTOR OPT CACCPT 31 40 41 COIN ACCEPTOR OK CASH/HETOND CASH EVEHTTHING ESCROW 42 44 48 60 61 62 MINIMUM CALL CHARGE REQUEST ADD COIK VALUE TO O.C.E. STACKS CASH ALL WITH 3 SEC DELAT TORES OPT IDEKT TORE OK CREDIT LOW ΤΟΚΕ OK TONES 63 64 70 81 82 SIART/CONTINUE COINTONES K.U. TORE OK EHD OT CALL ROUTINE SERVICE 1 SECOND TIMER START 11 SECOND TIMER START TIMERS 84 88 40 SECOND TIMER START 3 SECOND TIMER START CHARGE 90 CALL chars: HANDLER OPT HANDLER 91 RESET & TURK OK CALL «HAHE HANDLER POWER CO POWER - DOWN ROUTINE CALL END AUTO C1 AUTO-CALL ROUTINE BACKGROUND C2 INSULATE TEST ROUTINE CALL - 14 input EVENTS 01 AUTO CALL 5 02 HOOKING CALL 03 INSULATE BOWES UE 04- HANDSET LISTED (HS) 05 HANDSET DOWN (HS) OS CHAR® FOLSE 10 0? CHEDIT LOW 08 STOB CHEDIT LOW 09 CHEDIT EirPTTOU OA ATtTi OB OPERATOR CALL 15 00 Ν Τ BHEE/OP CALL OD COH VALIDATED QE LHE RECONNECTED OB B.O.C. ESESSED 10 Bo0.0. RELEASED 20 11 DIGIT KEYED 12 BOUETH DIGIT H MH CALL CHARGE 13 THIRD DIGIT H 14 COH COLLECTION COMEEETE 15 ESCROW BULL 25 16 SPACE H ESCROW 17 HH. CALL CHARGE AVAILABLE (MCA) 18 OPERATOR ANSWER SIGNAL RECEIVED 19 ONE OR ELECT SECOND TIMER BHISHED 1A BOETY SECOND TIMER BHISHED 30 1B NINE-NHE-NINE CALL KEYED 1C BOURTH DIGIT H WITH M.O.A. 1D TH HEW SECOND TIMER BHISHED 35 The above arrangement gives rise to a state list as follows:51965 - 15 STATE NODE LIST 1. POWERED DOWN 2. STANDBY 3. HANDSET LIFTED O.G. 4. WAIT POE CALL TYPE TEST RESULT . WAIT POE 4th DIGIT 6. AWAIT CALLED SOB ANSWER 7. oar,TED SUB ANSWER, 1st METER POISE, CALI IN PROG 8. CREDIT LOW INSERT MORE COINS 9. CREDIT EXPIRED . WAIT FCE P.O.C. REEEASE 11. CASHING 12. WAIT FOR RECONNECT 13. I/O CALL 14. ALL COINS CASHED . WAIT BEFORE POWER DOWN . FREE CALL . OPERATOR CALL & INDENT. CALL 31. WAITING FOR P.O.C. RELEASE 32. WAITING 33. OPERATOR CALL TO TONE 34. CASHING BEFORE OPERATOR CALI 36. CASHING COINS 37. CASHING COINS 50. AUTO CALL 59. ADTO/999 CALLS 60. INSULATE TEST The work place memory map for such an arrangement - 16 10 is shown in Fig. 3.

The method of programming is best described by tniri ng an example of one section, this is from the Rest State to Hand set Lifted (State 03).

It may be seen (In Fig. 3) that there are 4- input events which can cause the Micro Computer to ’Fower on Restart’ (FOES) These ares01 Auto Call An automatically generated call to report, for example a fault or coin box full.

Incoming call - Hinging detected.

Insulate Power Up - Insulate Line Test conditions detected. 04- Handset Lifted i.e. Normal 0/G Call.

Assuming that FCHS has been caused by Handset lifted (Fig. 3). This segment of Program sets various pointers in the workplace memory (HAM), clears this memory and does various Housekeeping activities.

V/hen ‘ROHS' is completed the.System State is set to 02 which together with Input Event 04- (Handset Lifted) in the input event stack (set by the Instack sub routine), causes 'Main' to look up the output event table.

'Back ground' then looks at the first event loaded in the output event stack - in this case 01. The next program module is ’Line’ so it acts on this to send a bit via an output latch to switch on the line transistors on the Line Interface Printed Circuit Board. The remaining program modules are then cycled through and return to ’Back Ground* (BCKGED) the next output event is set in the 51865 ’ 17 event stack, in this case 21 which refers to 'Display', the processors step through to the Display Module and actions this instruction. This sequence is repeated until the output event stack is exhausted and then the next system State is set.

If an interrupt occurs, it is handled at the end of the module of program then heing used. The delay before handling an interrupt does not exceed 100 microsecs.

At the start of each program module operation the 10 micro-processor is arranged to power up the required electronics for the particular function and at the completion of each program module the electronics is powered down to the stand by conditions.

Ihe above description has been of one embodiment 15 only and is intended to be exemplory only. Alternative arrangement will be seen by those skilled in the art for example although a micro-processor has been used descrete logic arrays could have been produced to achieve the program modules of the embodiment shown.

S1965

Claims (6)

1. A coin operated telephone instrument including means for monitoring for incoming calls and means for handling incoming calls and outgoing calls, wherein 5 the means for handling incoming calls and means for handling outgoing calls are adapted to he powered down when the telephone is idle and are arranged to be selectively poweredup as required when the instrument is taken into use.

2. A coin operated telephone instrument according 10 to eiaj m 1 in which the means for monitoring incoming calls and means for handling incoming and outgoing calls are controlled by a micro-processor. 5. A coin operated telephone instrument according to claim 2 in which the micro-processor is connected 15 through a bus system to act as the centre of a star network and the points of the star network are connected to (a) coin validator and coin management equipment (b) analogue and telephone line interface equipment and (c) keypad and display equipment and each equipment on 2o the points of the star include micro-processor controlled power switching arrangements allowing the micro-processor selectively to power-on or off the equipments at the points of the star.

3. 4. A coin operated telephone instrument according to 25 claim 3 in which the micro-processor operates under the control of software which is structured into a series of program modules which are handled on an interrupt basis and include steps for powering on and powering off as - 19 required, the equipment they administer.

4. 5. A coin operated telephone instrument according to claim 4 in which the micro-processor includes a memory and part of the memory is used to store a state map 5 and each program module is arranged to be activated by an entry in an input event stack and to mark an output event stack according to the module required to process the result of that module.

5. 6. A coin operated telephone instrument substantially

6. 10 as herein described with reference to the accompanying drawings. Dated this 19th day of June, 1981. By: TOMKINS &r€£L, Αωΐi canti' &jents, (Signed) /g, Dartmouth Road, DUBLIN 6. 51865 PLESSEY OVERSEAS LIMITED sheet 1 TOMKINS ?» Co. SIGNED BY............................ 51865 sheet 2 PLESSEY OVERSEAS LIMITED INPUT EVENTS I SYSTEM STATE SET TO 03 AFTER 6 CYCLES -,.,. I..,........ . .. ,. ,. ,, ,, ,, Lf) IS i -KEY BO STATE TO 02 CONNECT