Note: Descriptions are shown in the official language in which they were submitted.
10~420~
Thls invention relates to data processlng equipment and i9
particularly useful ior, but not limited in its application to,
automatic call recording equipme~t ~or recording details of
telephone calls to enable the charge for the call to be passed
to the correct 6ubscriber's account by an operator.
~t present the detsils for a telephone call connected by an
operator are written on a card or slip oi paper which is passed
- to an accounte department ior analysis and entry of the charge
aBainst the eubscriber~e account. Clearly the time taken to
write the necessary iniormation on the card to enable the charge
to be assessed correctly and set against the correct account
occupies a substantial proportion of the operator's time and
¢onsequently reduces the number oi call~ with which the operator
¢an deal. Moreover, the entry of the call details by hand is
liable to error and incorrect calculation of the charge or even
its lncorrect allocation. ~ny mistake oi this type results in
a lose o~ goodwill by the Post Oii~ice or other body operating
the telephone service and could result in a lose of revenue.
- It is thereiore desirable to provide some iorm of data
processing iacility to enable the operator rapldly to enter the
details o~ the call, but the system provided must be extremely
reliable because it will be extremely expensive to retain the
alternative handwritten system at present employed in addition
to providing the data processing iacility. It is moreover
essential at present to check a~ far as possible that the
operator has entered the correct inrormatlon into the data
- 2 - ~
10'~4209
processing system, and it is therefore desirable that the
system could incorporate some kind of feedback display and
any other check to which the information is susceptible.
It is an object of the present invention therefore to
provide a data processing system suitable for recording
details of telephone calls connected by an operator in which
the above requirements have been taken into consideration.
According to the present invention there is provided
data processing equipment having a plurality of independently
operating on-line stations and a plurality of data handling
units, the equipment including at each station data entry means,
data utilization means and control means, the control means
including storage means for recording in response to the data
entry means details of a required data processing operation,
and being capable of selectively generating in response to the
recorded details interrogation signals and instruction signals
for transmission to the data handling units, receiving data
from certain of the data handling units in response to the
interrogation and instruction signals and recording the data,
and applying signals to the utilization means, the equipment
further including monitoring means connected to all of the
data handling units and the control means, wherein each of the
control means and the data handling units includes a central
processing unit, a read-only-memory defining at least one
recurrent programme of instructions performed by the central
processing unit and a monitor message transmission unit, the
programme including functional tests on the operations performed
. . . ~ , :,
.
1094209
by the unit and the periodic initiation of the transmission
of a monitor message by the monitor message transmission unit,
the monitor message specifying any fault detected in the
operation of the unit, the monitoring means being connected
to receive the monitor messages from the control means and
the data handling units and having means for c~unting
separately the reports of malfunctions for each unit of
the equipment included in the messages.
Each station may be operated by an operator and the
utilization means may include display means for the operator.
The equipment may be for ~ecording details of manually
connected telephone calls and the data handling and/or storage
units may include a telephone call recording store to which
the details of a call are applied for storage by the control
means on completion of the call.
The data handling and/or storage units and the control
means may include a central processing unit arranged to perform
at least one recurring programme of instructions which includes
generation~of a signal indicating that the processing unit is
operating satisfactorily. The central processing unit may
include a watchdog timer to detect malfunction having a counter
which is incremented regularly and reset by an instruction
from the programme so that if the rccurrence of the programmes
is interrupted the count in the counter will exceed a threshold
value and produce an output indicating malfunction. A
respective data storage means may be associated with each
central processing unit and the central processing unit may
~ _
~09~209
respond to the respective output indicating malfunction to
erase all data from the data storage means and cause the
programme to be restarted. The equipment may include a
plurality of control means each associated with a group of
data entry and utilisation means having access to all of the
data handling and/or storage units.
In the monitoring means a store may be provided for
recording reports of faults and breakdowns referring to the
particular unit concerned~and the type of breakdown or fault
reported. A threshold may be provided associated with each
category of failure and an output produced only if the number
of failures exceed the threshold.
A diagonistic unit may be provided coupled to the
monitoring means to enable a wide range of tests to be
performed by an engineer. The programme information and any
other data required for the test may be recorded on, for
example, a magnetic tape cartridge insertable in the diagnostic
unit. The diagnostic unit may include a hot stand-by unit
for providing tested spare sub-units.
In order that the invention may be fully understood and
readily carried into effect an embodiment in the form of
manually connected telephone call recording equipment will
now be described with reference to the accompanying
drawings, of which:-
FIGURE 1 shows in block diagrammatic form the
telephone call recording equipment,
FIGURE 2 shows in block diagrammatic form the
circuit of an operator's control unit (OCU),
-- 5 --
~094Z09
FIGURE 6 shows the circuit of a monitor unit;
FI~URE 7 shows the coupling of CPU monitor units
to a monitor unit, and
FIGURE 8 shows details of the ~CU switchover circuits.
As shown in Figure 1, the call recording equipment
includes a plurality of operator's position equipment (OPE)
11 to 18, 21 to 28, 31 to 38, etc., each for an operator and
which are connected to operator control units (OCU) 10, 20, 30,
etc. Each OCU is arranged to receive information from and
return information to eight OPE's divided into two groups of
four OPE's. Each OCU has connections to two highways "A" and
~B", having references 1 and 2, which highways are each
connected to three pairs of peripheral units 3A, 3B, 4A, 4B,
5A and 5B, which consist of magnetic cartridge recording
units, tariff and credit card verification units and charge
step and national to local code translation units, which are
respectively connected to the two highways. In addition each
OCU 10, 20, 30, etc. is connected to a monitor unit 6 and
the monitor unit 6 is also connected to the peripheral units
to receive signals from them to indicate their functional
state. The monitor ~nit has facilities for printing out
details of any abnormalities in the operation of the equipment
which it discovers during the periodical scanning of the
outputs of the OCU's and peripheral units. There is also
provided a diagnostic unit 7 which is connected to receive
the information recorded in the monitor unit and to operate
a diagnostic interface unit 8 for applying test signals via
6 -- - ~
~' ' '
.
10~1~20~
a diagnositic highway 9 to the OCU's and peripheral units
and for receiving reply signals over the same highway for
the purpose of assisting an engineer to discover the reason
for any faults which occur.
The components which form the OPE's need not all be
located at the operator's switchboard, but will include
key pads for operation by the operator and a visual dispaly
unit (VDU) for providing information in visual form for the
operator. The necessary logic and interface circuitry may
be provided at the operator's position or in the corresponding
OCU. The key pads may be entirely separate from the
keys and switches provided for control of the telephone
network by the operator but preferably there will be some
interconnection between these components to ~nsure that the
exact time from the connection of a call to its disconnection
are fed to the OCU,
- 6a -
10~4Z09
possibly together with detail~ o~ the number to be called and the
iacilit~ required by the sub~criber. The operator control untt
iB constructed to transmit the information required by the operator
to the vi6ual di~play unit, po~sibly also to ~lluminate certain
of the keys to provide ~ome oi the iniormation required or ior
promptlng the operation of certain keys and al~o to check the
correct operation oi the components o~ the OP~.
Ae mentlone~ above, each OC~ i8 connected to control ei~ht
O~E~B, but the OCU'e are constructed to be capable of handling
iniormation irom and ieeding lniormation into twelve OP~'s; each
OCU having two ~roupa oi four bu~fer stores, each bufier ~tore
being available ior the information irom and to a re~pective OP~,
and two stand-by units each for handling the inpu~ of four other `
O~E'e or ior transferring a group o~ four OP~'s to an ad~acent
0¢~. In the e~ent o-f a breakdown o~ an OC~ when discovered b~
teets periormed internally by each OCU, the eight OPEIB allocated
- to that OCU are divided into two groups of iour and trans~erred
to t~o ad~acent O¢U's. Eaoh OCU containe a m~oroprocessor which,
in the partlcular e~ample o~ the invention being con~idered is
an INTBL 8080~ or a compatible de~lce, and ress~bles a small
computer in which the required data proce~eing 1B e~fected by a
~ingle integrated circuit. It will be apparent that other types
oi microprocessor could be used, provlded that the facilities
re~uired by the OC~ are available. There are a~sociated with
each microprocessor the necessary power supplies, clock pulse
generators, data and programme stores and buiier stores.
_ 7 _
10~4Z09
A~ can be ~een from Figure 1, each of the periphoral
unlts 1~ provided in duplicate, and each unit lncludes a micro-
proce~sor ~imllar to that used in the OGU'e. The tariff and
credit card verification units 4A and 4~ store the in~ormati.on
about the tari~f rate~ of the di*ferent telephone connections
possible or other iacilitle~ ~uch as, for example, provision of
peraon~ call, etc. As the tariff rate will depend upon the time
o~ day at which the call iB made, these units will al80 include
independent clocks dri~en by so-called watch-dog timers and
supplying thls time 80 that the correct tariff rate ~or the call
i8 provided and is transierred to the oou. Facilities are
provided ~or resettlng the clocks under engineer control. ~5
certain sub3cribers require the facility for charging telephone
calle to a credit card account, it i5 nece3~ary for the operator
to be able to check the validity og the credit card number gi~en
by the caller, and for this purpo~e the tariff and credit card
verification units are able to check the number and indicate to
the operator whether the number given i~ valld or invalid-
~hese units may also provlde other in~ormation such as, for
example, when a particular account ha~ been discontinued.
Another facility provlded by the peripheral units i6
~ound in units 5A and 5~ and is the charge step data and national
to looal code tr~lslation information which are u~ed for providine
iniormatlon to the operator with regard to dialling codes to
be emplo~.ed for particular operat1ons or conne~ions, and tells
the OCU the distance factor in the conne~ion being made so that
the appropriate charge rate i8 used.
- 8 -
~0 94 ZO9
In addit~on to providlng tarif~ data ~nd the credlt card
~eriilcation, each of the units 4A ~nd 4~ includes a clock giving
the time of day, thi~ in~o~ation being requlred because the call
.- tariff depends on the time at which the call is made. The clocks
in the two units are lndependent but are checXed against each
other every 30 minutes and i~ the error is greater than 30
seconds a signAl indicating this is sent to the monitor unit 6
for reporting to the engineer. On receiving the report the
engineer u~es the diagnostic l~n;t 7 to reset both clocks to
10 - the time provided by a reference clock.
The most importa~t ta~k of the peripheral unlts is
iulfille~ by the magnetic cartridge recording unit~ ~A and 3B
whi~h record ln dupllcate on two separate magnetic tape cartrldge~
deta~ls of the oalls handled by the operator, together with the
15 . subsoriber's identiiication either by way o~ hi~ telephone
nwmber or credit card number, ior example. On to the cartridge
~ are also recorded the length o~ the call, the time of day, the
tari~i unit and any other details such as i~ the call is a
personal call. When a magnetic cartridge has been filled or
at the end of a particular period the cartridge is repla~ed and
the full cartridge ie passed to a central acco~ting department
where the charges ior the calls are calculated and set against
the subscribers' account~.
All of the peripheral units are duplicated as are the
highways 1 and 2 coupling them to the OC~'s 80 as to en~ure that
a sinele iault cannot disable any part of the system~ Moreover,
_ g _
1()94209
it i8 poe~ible ~or a faulty unit to be tes~ed and repalred
without interrupting the effectivene~s of the system as far as
the operator~ are concerned. To enable the engineers rapidly
to locate and repair ~aults in any part o~ the ~ystem, there is
provided the monitor unit 6 which is connected to each oou and
each per~pheraJ unit via a ~ystem o~ independent highways which
enable the per~ormance of each unit to be aY~essed in re~ponse
to relevant parameters such as, for e~ample, the state of ~ill
oi buifer stores provided in the units. In addition, the micro- i
proces~ors in the unit~ are programmcd to assess their o~n
functioning and to transmit a message that all is weil or that
there is a ~ault with the particular unit periodically to the
~onitor unit. In one e~ample reporting mes~ages are applied to
- the monitor unit irom each oi the OCU'8 and peripheral units
every four ~econds; ~he monitor unit provide~ a printed output
by means o~ a teleprinter 6A, which ou~put will enable the over-
~11 periormance of the system to be checked and will also provide
statistical information which will enable deci~ion~ to be made
as to the neces~ity for iurther operator~ or other peripheral
unita to be provided or not.
W~en the monltor unit 6 is not able to identi~y precisely
the ~aulty equipment, a maintenance engineer iB able to use a
diagnostic unit 7 whloh includes a ~urther microprocessor and
has a large repertoire of diagnostic instructions avai~a~le on
test cartridges wbich can be inserted in the unit 7 at 7A. The
diagnostic unit 7 i~ designed to diagnose ard localise ~aults
.
-- 10 --
~03420~
in any o~ the unlts and i~ arranged to do thia in such a way
that it can be utilised by non-speciPlist staff who have no
knowledge oi the data processing equipment in~ uded in the
system. In order to per~orm the diagnosis the unit 7 initiates
a test signal which i~ applied over a diagnosis highway system q
via an interiace 8 either to the operator control units or to
the peripheral unlts and appropriate output signals are
returned to the diagnostic unit 7 over the same highway system 9
and interiace 8. ~he teleprinter 6A enables the engineer to
enter lnstructions and data via its keyboard and prints out the
re~ults. The teleprinter 6A is connected to the monitor unit 6
via a V24 link, a second such link connectlng the unit 6 to
the diagnostic unlt 7. .
. Another iunction o~ the diagno~tic unit 7 i8 to enable
15 . data to be entered into the tarlii and credit card veri~ication '
units 4~ and 4B, since it is likely that the credit card data
at lea~t will.be changed irequently. .
The CP~18 may break down in service and thereiore are
programmed to carry out periodic checks to supervise their 1.
operational condition and that of the units which they control.
~o achie~e this each unit includes a watch-dog timer ~hich
¢on~lsts of a counter to whlch pulse~ are applied having repe-
tltion ~requency oi 1 kXz. ~he programmes oi the microprocessor
inoluded ln the unit are arranged to access the counter at
interrals not gr~ater than a quarter oi a second ~nd to reset
lt to a count oi 0. Ii the counter i~ not aocessed during this
.
1094Z09
tlme, for e~Rmple by reason of a ~ailure of the programme to
e~tricate the microprocessor from the loop oi instructions or
as a result Or hardware iailure in the mlcroproce~sor, the
counter, when not accessed, ~tarts a "time out" to allow a
further period of time for the counter to be accessed. Failure
to access the counter within thi~ further period oi time results
in the programme~ oi the microproces~or being interrupted and
being reset to a datum position in th~ programme sequence and
the associated data store being cleared. A flag is set when
the programme interruption occurs and signals are sent to the
monitor unit to cause it to record t~e details of the failure.
A second failure to access the counter within the quarter
second time interval results in the unit being recorded as
having broken down, and at this time if the unit is an OCU
a switch over of the OPE inputs to adjacent two OCU's is effected.
AB deeoribed above eaoh OCU recei~e~ inputs ~rom eight
OPE'~ but are ¢apable o~ receiving ~nputs irom twelve OP$'~.
Consequently on the breaXdown oi an oo~ the OPE'e normal}y
assooiated with lt are traneferred as two groups of iour to
reepeotlve other OoU~B BO ae to make thelr complement~ up
to twelve.
~ he lnputs ~rom the OPE's to the OoU~s are ied ln groups
oi iour to respective "flrst ln ilrst out" buiier stores
included in 0~ common unlts. I~ elther of these buffer
' ` 25 store~ become~ iillea lt ie as~umea that for some reason the
oou has bro~en ~own ana iB unable to handle the inputs. In the
- 12 -
1094209
same ~ay as described above a breakdown is indicated snd 18
also dealt with by tran~er o~ the OPE's to adjscent OCU~8. As
beiore an indication is sent to the monitor unit 6 to record -the
ialiure of the OF~.
The entire system i~ con~tructed 80 that every part i~
at lea~t duplicated with the result that signals can be re-
routed to other units in the event oi a breakdown. As described
above the OCU's are arranged ~o that their iunc~ion~ can be
taken over by other OC~'s in the event of i~ailure and the peri-
p~eral l~n~ ts are al80 duplicated 80 that ii one unit iails the
duplicate i~ able to continue per~orming the required iunction.
Bach OCU ie programmed to receive a response over each oi the
highways "A" and "B" irom the units to which it has sènt an
en~uiry, one response coming irom the unit connected to hignway
"A" and one irom its duplicate connected to highway ll~n, ~he
OCU then compares the re~ponses and takes the decision as to
whlch slgnal 1B correct, lf they diifer. The sig~al~ include
simple check lniormation such as one or more parity digit~ to
enable a ~alldlty te~t to be made on the data so that obviously
ln~alld data can be discovered without dliilculty. On the other
hand ir an OC~ receive~ re6ponses whlch dlifer but both oi
whlch appear to be valld it produce~ a ~lgnal ior the operator
ooncerned lndlcating that lt oannot a¢cept the data because it
cannot deoide which 18 correct. Under theee conditions the
operator must re~ert to the u~ual reierence book~ ior ascer-
tQlning the lnrormation required. Any failu~e of this kind i9
- 13 -
109~Z09
automatically reported to the monitor unit ~nd tha e~ineer ls
then able to carry out tests to a~oertain ~hlch part of the
~y~tem has ~ailed and to re~tore it to ~ull operation agaln.
In addition the magne~ic recording cartridge units ~A
and ~B which are al80 provided in duplicate Pnd connected
respectively to the highways "A" and '`B", have a checking unit
connected in their inputs to ensure that the data recorded on
the cartridges are as iar as possible correct. In the input ~o
each unit there i9 provided a "~ir~t in iirst out" (FIFO)
bui~er and the data stored ~n these buifers are compared. If
the data are identical in both buffers then the recording unit8
are arran~ed to record the data. If the data in the two
buffers dlifer then each i8 tested for validity on the basis
o~ a ~imple check, for e~ample a parity check, and ii one ~et ~ i
data is wrong then the ~alid data 2re recorded ln both un~ts.
On the other hand, if the data differ but both ~ets of data
appear to be ~alid then each recording unit is arranged to
record the data stored in its own bu~fer and an indication i~
eant to the monltor unit to indicate that the two sets oi data
diiier. It is al80 possible that a mark oi some kind be
entQred on the records at this point to indioate that the data
immediately precediDg the mark or immediately following it
are suspect.
Figure 2 shows the construction o~ an operator's control
unit (oo~) and lts connection to eight OP~'s and to two
ad~acent OCU's ior the purpose o~ handing o~er the OPE's in
.
~o9~zo9
two block~ cf ~our to the adj2cent OC~'s in the ev~llt of a
breakdo~m. The s~me interconnection between thc OCU's is used
for the handing over by one of the ad3acent OCU'9 0~ a block of
i'our OPE's, should the particular ad~acent OC~ break down. The
dotted rectangle lOG encloses the components constituting an
OCU number N, part of oau number ~1 being ~hown partly enclosed
b7 dotted line 101, and a connection to OC~ N-l being lndicated
at 102. In addition to the components shown or indicated, each
O~U includes power supplies and a pulse generator which supplies
the 8i~nal9 requirad by the microprocessor.
The eight OPE 1 9 allocated to the OCU ~N" are indicated
as 103 to 110 and are connected to respective data control units
111 to 118 in the oo~. ~he data control units have some buifer
storage and other functions such a~ checking the validity oi
the signals reoeived irom the OP~9 and performing some code
conversion~, ior e~ample. ~he data control units are connected
in ~roups oi ~our to OPE common units 119 and 120 by m~ans oi
whioh the signal~ irom the OPE's are multiplexed for application
to a bu~ highway 121 which forms the main communication link
between the microproces~or and its associated unlts. Each OP~
common unit lnoludes a "~irst ln, iirst out" (~I~O) bu~ier
store (see ~igure 8) ior receiving data and inst~otions irom
the OPE e~ enabling them to be retimed ior processing by the
mlcroprocessor ln the OCU,
The microprocessor itself i~ contained in a central
proces~ing unit (CPU) 122 and i~ co~nected oy means of the
- 15 -
10'?4209
highway 121 to a random access memory (RAM) 12~, a pro~rammable
read-only memory (PROM) 124, a C~U monitor 125, and t~o peri-
pheral unit selector8 (PS) 126 and 127. In addition, facilities
are provided for plugging ln a printed circu~t board "te~t
access" 128 for coupling the d~agnostic unit into the O~U. The
CP~ monitor 125 i8 connected directly to the monitor unit ~Fig.l)
and the peripheral l~n~t selectors 126 snd 127 are connected
re8pecti~ely to the highways "A" and "~ ig.l).
Stand-by units 129 and 1~0 are connected respecti~ely to
the OP~ common units 119 and 120 and al80 to the bus highway
121. ~nit 129 is connected via connection 102 to oo~ "N-ln
and the unit 120 is connected to oo~ "N~
As80ciated with the CP~ 122 and possibly incorporated
in the mioroproces80r-(but shown separately from the CPU for
clarity is a watch-dog timer 131, and in the RAM 123 by software
time-out queues 132 and a peripheral request queue 133, the
_ functions of which will be described later. Engineer's keys 134
are provided connected to the bus highway 121 for enabling an
engineer to have direct control of the OCU shou&d he require it.
A power supply unit and a pulse gererator, neither of which are
shown, would be provided to drive and energize the components
of the OCU.
The CPU 122 performs the processings of the signals from
the OPE' 8, transferring enquiries to the various peripheral
units as required in the following way. The operations of the
CPU are divided into 16 multiplexed time slots of which 12 are
allocated to the 12 OPE's (the eight OPE's normally handled by
- 16 -
10~4Z09
the OCU plus th~ 4 e~tra OP~'s taken over i* the adjacent O~U
iall~), one is allocated to the watch-do~ timer and thæ time-
outs (indications th~t speci~lc time intervals have elapsed),
two are allocated to the peripheral selector~ and one is
allocated to the engineer's keys via which the engineer can
enter data or special instructions into the OCU. It uill be
appreciated that buiier stores must be employed with a processor
operati~g in this way because the actual time o~ making use oi
or producing any particular item oi data depends on the time
slot to which it relates. If a signal irom an OPE is held in
~ne oi the buiiers in the OPE common nnits 119 and 120, the
CPU 122 at the appropriate time slot responds to the ~ignal to
record the data or start processing in a conventional manner,
that i8 to ~ay UBing storage registers in the ~AM 123 allocated
lS to the particular time slot to store the data ~nd initial and
interm~diate results of calculations in response to instruction~
deri~ed irom the PRO~ 124. A typical signal from an OPE would
be a request ~or data from one of the peripheral unit~, and-
the CP~ would respond to such a signal by attempting to pass on
a request ior the data to the peripheral unit concerned.
Probably the peripheral unit would not be acces~ible at the
particulsr instant and therefore the request would be placed at
the end oi the queue stored in the peripheral request queue
store 133, and when the request reaches the head of the queue
the details are selected by the CPU 122 irom the RAM 123 and
passed via the selectors 126 and 127 to the peripheral UDit
- 17 -
109~209
concerned. Th~ dsta received from the peripheral unit would be
routed by the CP~ 122 into the RAM 123 ready for return to the
OPE. Each OCU is able to handle 84 call~ at a time, i.e~ 7
- calls ~rom each OPE, and the data ~tored in the peripheral
reque~t queue takes the form of a call tag, that i~ to say a
number between 1 and 84, by which the call concerned is known
to the OC~.
The timing of operations is controlled by a pulse
generator, not shown, from which pulse~ are applied to the
watch-dog timer 131~ which in turn applies ~ignal~ to the time-
out queues storsd in the unit 132. ~he ~unction of the time-out
queues is to produce signals after particular inte~als of time,
such as, ~or e~ample, 3 minutes ior the call time from a i
public call box, which interv~l ~orm~ the unit o~ time ~or a
pre-paid call. As described above, the watch-dog timer 1~1
include6 a counter which is reset to zero every time the timer
iB aocessed, so that in the event of a breakdown of the normal
sequence of instructions o~ the CP~ 122 which results in the
timer 1~1 not being access~d, the counter would reach a value
higher t~an lt would reach in normal operation, thus providing
an indication of the breakdown and in response to which the
programmes o~ the CPU 122 are reRet to a datum po~ition and
restarted.
In addition to monitoring the satisfactory ~unctioning
o~ the OC~ by means of the watch-dog timer, the monitor 6 i8
arranged to receive from the O~U periodic ~ignals produced
- 18 -
~094209
during progra~me e~ecution indicatin~ its satlsfactory operation
and also statistical data relating to the calls which it has
handled. Items o~ statistical data are applied by the CP~ 122
to the buf~er in the unit 125 during the time ~lot allocated to
the CPU monitor, so that during the operation o~ the e~change
the statistical data i~ built up in the monitor unit 6.
The si~teenth time slot i9 available ior the engineer'~
keys 134 in the event of a breakdown oi the OCU, thus enabling
the engineer to instruct the CP~ 122 directly and diagnose the
cause oi any iaults or failures in the OC~.
Among~t other storage iacilities provided by the RAM 123
i8 a call store having 84 addresses, one ior each call, in
which details of the calls are recorded as they are entered by
the operator. When the call is completed the relevant details
are ~ent by the CPU to the magnetic cartridge units 3A and 3
ior charging and to the monitor unit 6 ~or ~tati~tical purposes.
An operator's position store is al~o included ~hich relates
the switches at the operator's position to the call tag or
number.
In the event oi breakdown oi the OF~ "N", detected
either by the watch-dog timer or by the iilling of one or more
oi the input FIFO bufiers in the data control units, the CPU
monitor 125 ~ends signals to the stand-by units 129 and 130
causing them to route the outputs oi the OPE common units 119
and 120 to the stand-~y u~its in ~he adjacent OoUt8. The CPU's
in the OC~'~ are progra~med to test the stand-by unit~ in each
-- 19 ~
'
109;-~209
multiple~ cycle to a~certain whether signals from four e~tr~
OPE's are being applied to the OCU or not. If the ~our e~tra
OP~'s are allocated to a particular OCU then its CP~ will
address the extra OPE's in the same way as the original eight
OP~'s allocated to the oo~ 80 that the op~rations required by
the e~tra OPE's are ~itted into the schedule oi work periormed
by the OC~. .
Figure 8 shows further details of the mechani~m in an
OC~ to provide ~or the changeover of groups o~ OPE's to adjacent
OCU'e. Two groups of iour OPE's are connected via two ~IFO
.
- common bui~ers 701 and 702 respectively to storage bu~fers "~
and "B" having the reierence~ 70~ and 704. The bu~fers 703
and 704 each have two outputs o~ which one is connected to CP~
700 belonging to the OCU in question, and oi which the other
18 connected to a re~pective stand-by CP~ belonging to an
ad~aoent OCU. A CPU monitor unit 705 contains an OR-gate 706
having input3 from the FIFO bu~ers 701 and 702 if these
become iull, an lnput irom a ~ second time-out unit 707
included in the CP~ monitor 705 and an input ~rom a pul~e
generator 708 which supplies energizlng pulses to the C~ 700
indicating that one or more sequences of pulses has failed. A
iurther input 709 i9 provided to enable an engineer to chec~
the switch-over operation manually. The output of the gate
706 i9 connected to the bu~fers 703 and 704 to e~iect the
switch-over control o~ these bu~iers to or from the stand-by
CP~
- 20 -
~0~42(~
~lgure ~ shows the detail~ oi the diaeno~tic unit
(~ig.l) ~rom -~hich lt can be seen that the unit consi~ts o~ an
active part termed a test control unit and iormed by units
below the bro~en line which are co~nected to a bus highway 200
and a passive part termed a hot ~tand-by unit and iormed by
the unlts above the broken line and co~nected to a bus high~ay
220. The units ~o~min$ the passive part are on "hot stand-by
that iB to say they are in operation r~peatedly undergoing~ a
sequence of tests under the command of the CPU18 201 and 212,
~o that an engineer can extract one of the unit~ for use in the
oquipment ~ollowing a breakdown ~ecure in the knowledge that the
unit he has taken i~ iully operational, whereas a unit idle on
a sheli may have a fault.
~nits CP~ 201, RAM 202, PROMs 203~. and 203B, and CP~
monitor 204 constitute a data proces~ing unit, such as iQ use~
in many units ln the system, controlling the tests perioImed by
- the diagnostlc unit, and these units are interconnected by the
bus highway 200. Al~o connected to the bus highway 2~0 are a
V24 unit 208 the function of which will be described in detail
later, an interzone channel ~O9 which is connected to the
tarif~ and credit card veriiicatio~ units 4A ana 4~ ~or the
purpose oi entering specliic data into those units, and a Qecond
V24 unit 210 which connects the test control unit directly to
the monitor unit 6 for the purpose of receiving in~tructions --
~rom that unit as mentioned above. A Qpecial maintenanoe hlgh-
way ~rom ~he monitor unit 6 ig connected throu~h a monitor unit
1094209
223 to the bu~ highway 2~0, and ma~netic +ape cartridge units
225A and 225B are provided to e~able an engineer to enter quickly
epeclal lnstruction~ or data for diagnostic test procedures.
~'he blockc 226, 227 and 228 indicate po~sible positions ior
other PROMs ior diagnostic test programmes. ~ iurther V24
unlt lncluded within the dotted rectangle 211 i8 also oonnected
to the bus highway 200 and together with the V24 unit 208
provide~ the double interconnection oi the hot stand-by unit
wlth the te~t control unit, the two V24 units being respectively
connected to the bus highway 220 by means oi V24 units 218 and
that inoluded in diagnostic interiace 222. The interiace 222
can be detached irom the highway 220 and connected to the bus
highway oi any other unit in the systam, the connection being
indioated on the dlagram~ oi these unitS as test acce~s 90 as to
enabIe the test cont~ol unit to have access to the components o~
the partioular unit to enable diagno~itic test procedurea to be
~ oarried out.
The hot stand-by unit, a~ explalned above, contains a
number oi oompon0ntc, ~or example, ln the form of printed circult
boarde, which are continually e~ercl~ed ~ndcr 'he control of a
CP~ 212, a R~M 213 and a PROM 214, all of which are connected to
the highway 220. ~he oomponente them~elves are a peripheral
selector 206, an OPE common unit 207, a perlpheral input-output
unit 216, an oPæ teet unit 217, two data controller~ 224A and
224B, an interzone channel 219, an OP~ bu~fer 221, and a
monitor input unit 205 connected to a CP~ monitor un~t 215.
- 22 -
10~4Z09
In order to permit the~e units to interact in the ~anner in
which they are con~tructed to do when in service, apart from
the connection o~ the 0PU monitor 215 to the monitor input unit
205 mentioned above, the peripheral ~elector 206 is connected
to the periphsral input-output unit 216, the OPE test unit 217
ie conn~cted to the data controller~ 224A and 224B, the interzone
ohannel 219 ha8 it~ outputs interconnected a~ are the outputs
of the 0P~ bu~fer 221 which i9 controlled by the CPU monitor
215 to ef~ect the e~itch-over o~ thls bufrer as de~cribed with
referance to the buffers 703 and 704 of Figure 8.
Power supply units 230 and 232 and p~lse generators 231
and 233 are provided respectively for the te~t control unit and
the hot stand-by unit, which two units are constructed o~ k
s~milar ¢omponents eo as to standardise their a~sembly.
~he diagno~tio unlt provides the following ~ac~litie~:-
1. Storage ~or range o~ detail diagnostic programmes. -
~ 2. ~ iacility to keep a stand-by including one o~
all basi¢ ~ystem card~ in hot proven ~tate, with
alarm if a failure occurs in one of the ~tand-by
cards.
3. Engineer access to ¢ontrol diagnostic programmes
and produce as an output the re~ults of tho~e
programmes. This access is vla the teleprinter 6A
on the monitor unit through a V24 link between
the monitor unit and the diagnostic unit.
- 23 -
109~209
4. h fa~ ity ior inpu~ting and oading secured data
~ableZ~Zl~ e.g. tariif data, translation data and
credit card Ztop liZZt.
5. A facility to resy~chronlse the 2 reZ~l time clock~ZZ
in the tariff peripheral equipments.
The diagno~tic interiace unit 8 provides the iollowing
iacilities:-
1. hn ability to interrupt the programmeZ oi an
addre~E!Zed CPU to run a teZZt programme derived
from a PROM included in the unit 8.
2. Running the P~OM programme to test out basic CP~,
pulse generator and RAM combination of an
addreZl~ed unit.
3. Provide acceEZZs for the addresZZed CP~ to read
programmes irom the diagnostic unit.
When a fault occur1 the monitor unit 6 will indicate at least
~ which unit, i.e. OC~, peripheral zone, has failed or at best
which card has iailed. The diagnoZltic interiace will then be
plugged into the iaulty unit. The interrupt is then operated Z
to start the CPU reading the diagno~tic PROM programme b~
engineer control at the teleprinter 6~. If this fails to
identiiy the iault then one oi the iollowing card~ ba9Z failed.
- 1. the power supply, separately alarmed hence such
a iailure will be self evident.
2. ~he pulse generator - there is an alarm on the
slowest clock pulZZle iZs.a iailure will normally
aiiect the sloweZZt clock pul~e and hence indicate
the failure by alarming.
- ~4 -
~' ~
~0~4209
. the R~M card - norm~lly 2 RAM cards are u~ed hence
by testing with the other RAM card a good test can
be run, i~-the ~ault ia in the RAM card.
4. thc CP~.
From this in~ormation a ~ault that i~ not already evident
or can be cleared by attempting to run the other RAM card, will
normally be in the CP~. By using the hot stand-by CEU fro~ the
diagnostic unit, the test can be re-run. Another failure may
be caused by the pul~e generator, otherwise it is a ~ery unusual
fault consisting oi a continuous corruption on the bus highway.
This can be proved by plaoing the suspec~ed faulty CP~ in the
hot stand-by position to see ii it runs successfully~ If ~t
runs correctly then it is a highway fault. Once a good CPU,
pul~e generator, power supply and R~M have been establi~hed
tests can be run to te~t the~ROM, CPU monitor and input/output
devlces. In this way the fault can very eæ~ be reduced to
_ a single card. Several cards may have to be removed and
replaced li the ~ault is in the pulse generator or power supply
and doea not generate the alarms on these cards, or there is a
fault interfering with the bua highway, w~ich may require a
number of cards to be disconnected to clear peraistent inter-
ference then by test1ng aa the cards are reconnected the
faulty card can be isolsted.
Figure 4 shows the circuit of sny of the peripheral
units, except the magnetic cartridge recorder. ~he periphera~
units differ only in the progr~mming of the read-only memorie~.
- 25 -
' ., ' ~ . '
10~34;~)9
AB can be seen the construction sho~n in Figure 4 i~ ~imilar
to that o~ other unit~, such ~e th~ ope~tor control units and
the diagno~tic unit, as far ~8 the dRtP process~ng p~rt o~ t~le
circuit, formed by CP~ ~07, RAM 306, PROM 305 and CPU monitor
304, i~ concerned but di~ers in the provl~ion of three peri-
pheral I/O control unit~ 301 to 303 connected to the bus highway
300. Bach peripheral I/O control unit i9 connected to group3
- o~ the OC~'~ (Fig.l).
~he circuit o~ the magnetic cartridge recorder is s~own
in Figure 5 and iB similar to that ~hown in Figure 4 with the
additlon of an tnterzone channel unit 401 and magnetic tape
to CPU and magneti~ tape cartridge interfaceæ 402 and 403 and
a dual tape cartridge unit 404. ~ power supply for the
cartridge unit is provided by unit 415. The units 401 and 402
are connected to the bus highway 400. Al~o connected ~o the
bus highway 400 are three peripheral I/O control units 410,
411 and 412, CPU 406, RAM 407, PROM 408 and CPU monitor unit
405. As was explained earlier the data applied via highways
"A" and "B" to the magnetic tape cartridge units are compared,
and this is the function of the interzone ch~nnel unit 401
together with a similar unit in the other magnetic cartridge
unit (the peripheral units are referred as belonging to zone
~A" or zone "B" depending on the highway to which they are
connected). The unit 404 is a dual cartridge unit to permit
the magnetic cartridge to be changed without interfering with
recording. A power supply 413 and a pulse generator 414 are
provided to energize the circuits.
- 26 -
..
109~209
The monitor unit is shown in Figure 6 and again utili~es
the ~ame data processor construction, wi'h a ~P~ 508, a RAM 509
~nd a PROM 510 connected to a bus highway 500, but in this unit
four monitor input units 501 to 504 are provided connected to
the bus highway 500, the monitor input units having direct
co~nections to the rest of the equipment ~hown in Figure 1 for
the purpose o~ receiving the signals ~rom the CP~ monitor units.
I~ addition two dual V24 code interface units 506 and
507 are provided ior connecting the monitor unit to a teletype
printer a paper tape punch and the diagno~tic unit.
A power supply 512 and a pulse generator 513 are
provided.
The monitor unit 6 receive~ data from OC~'s and peri-
pherals which can be divided into two types. These are
statlstic~ and difficulty lniormation ~rom OCU's and iault
reports from OC~' 8 and peripherals.
_ The unit 6 produces statistics and di~ficulty information
a8 both print-out and punched tape in~ormatlon. Depending on
the ~ize oi the installation the print-out will be on the
printer 6A or on a ~eparate dedicated printer (not shown). If
- a separate printer i# used the eng~neer will need to key a
epecif1c instruction to de~ine this. The main bulk o~ statistics
i8 not required regularly and will only be provided when a
marker i# #et by an engineer request via the maintenance printer.
The information required at all time includes:
,_
- 27 -
. ~
` ~ ~ ` - `
10~2 ~
the total number of stati~tics me~3age~ recei~ed from
O~U~t ~or every 15 minute period,
the percentage of cælls answered in 15 seconds (accurate
to one decimal place) for every 15 minute period as obtained
irom Q COUNT circuits, and
~he average ~umber o~ poEtitionEI stæ~fed ~or each 15
~inute period. When each operator start~ work on a switchboard
a "~æADSET I~" signal iB sent to the OFU ana when sh~ leaves
the ~itc~board a "HEADS~T O~T" signal i~ sent. The OCU sends
the monitor unit a mes~age every 16 seconds which includes 'he
switchboards in serYice. The monitor unit marks a pointer ~or
each po~ition on receipt of this in~ormation and averages the
number of in u~e positions over a 15 minute period.
- ~hi~ stati~tical iniormation i~ generated and stored in
a "~tats Output Bu~ier" every 15 minute~ and once every 4 hours
all the data in the buffer is printed out with appropriate ~-
statements to e~plain the meaning of the data.
Part o~ the maintenance control provided by the monitor
unit 6 i8 a check on the tari~f unit6 4~ and 4B to ensure the
two real time clocks are in ~ync. ~he tariif units send
messagee to the monitor unit~ every ~ hour containing a num~er
in the range 0 to 95 identi~ying the pa~t ~ hour in a 24 hour
period, and the date.
~8 well as the print-out, all the information i~ punched
on paper tape. A tape punch will be provided at every in~tal-
lation but a dedicated printer ior~the print-out will only be
- 28 -
,
~9 42 ~9
. .
provided on larger insta~lation~. Confl~ct ~y occur betw~en
the mainten~nce and statistical u~es o~ the ~onitor tlnit 6 and
al80 0~ the di~gno~tic unit 7 and a routine could be devi~ed
*or ~eali~g with these.
Dif~iculty messages are received ~rom the OCU when the
operator wi~he~ to record either a subscriber's or her own
dif~iculty in setting up calls in the telephone network. This
information i~ useful to maintenance sta~ lor d~tecting ~aults
in the network. A message is received ~rom the OC~ ~or each
report and this i3 stored by the monitor unit 6 ready to print-
out. A cyclic buf~er o~ 4~ bytes i~ used and a print-out made
~hen the buffer is ~ ~ull, a statistical print-out is made or
by engineer request. To aid engineer interpretation of this ',
data, the time to the nearest ~ hour will be recorded for each
di~flculty call indicating the time when it was received by
the monitor unit 6. Po~sible conflict may be dealt ~ith in
~ the same way as for statl~tical in~ormation. I~
Fault report~ are generated by 0~18 and peripherals
when a malfunction occur~. The monitor unit 6 i designed to
e~pe¢t a maximum o~ 128 message type~ frcm the OC~ and 128 types
~rom the peripherals identiiying the fault~. The ~ault reports
are used to increment 8 bit counts in an array of count~. Two
arrays are used, one array of OCU identity on one axis and
message type on the other and the other array of peripheral j .
identity on one axis and message type on the other. Each row
and column will have associated with it threshold counts defi-
ning at what count a fault report ought to be recorded and
- 29 -
.
10~4Z09
brought to the maintenance engineer'~ notice. Normally the
threshold counts will be ~l~ed values, i.e. part of the programme.
~owever to provide ~lexibility the eng~neer will be able to set
-variable thre~hold levels when required. Thus two sets of
thresholds per array will be used, i~ the variable threshold is
not in u~e the fixed threshold is used. ~o enable spurious
signals to be regularly cleared, at midnight the two working
arrays will be cleared and the counts trans~erred to the
"~istory Filo". The engineer can control, via the teleprinter,
the action taken when upaating the History File at midnight.
~y instruction the programme will not simply overwrlte the
~lstory File, but add the last 24 hour period to the exi~ting
History File counts enabling a set o~ counts over a number of
days to be accu~ulated. The engineer can reque~t a print-out
of the e~isting History ~ile at a~y time. To simplify reference
to the two working arrays the engineer re~ers to a "device
number" which defines a particular OCU or peripheral unit and
a "message type". The first 128 types will be allocated to
0 W's and the second 128 for peripherals. It can be useful for
the engineer to acces~ and control counts in "groups". These
eroups are defined by the device they relate to, e.g. rows of
OCU file relating to a particular peripheral unit and the
message irom that peripheral unit (i.e. column in peripheral
wor~ing ~ile). Message counts can be printed, cleared and
threshold set o~ a group basi~ in the same way as on a per row
or column basis.
-- ~0 --
10'~4209
To pro~ide further engi~eer control of thre~holds a
time controlled thre~hold facility is also provided, which
enables the engineer to speci~y a threshold cou~t o~er a timed
period.
In certain situations the engineer will req~ure to 3et
speclfic count thresholds, e.g. a particular me~sage report
~rom a particular OCU. ~his threshold setting oi single counte
i8 provided in a limited way by using a separate li~t ~rom
the main working arrays.
Ii a threshold i8 reached the total count ior the row
or colum~ i~ checked to see if other reports are being received
from the oou or peripheral (column check) or the same mes~age
type ~rom di~ierent OC~'s or peripherals (row check). lf the
row/column total count ha~ reached double the threshold ~alue,
the appropriate fault report is generated.
Reports o~ sstisfactory operation are received from each
_ OCU and peripheral unit every 4 seconds. An 8 second time-out
is set by the so~tware and if the time-out e~pires before the
ne~t satisiactory report is received the appropriate message
count is incremented. A threshold is set in exactly the same
way as ordinary maintenance reports received from OC~8 or
peripherals.
When a iault report is generated the appropriate row
or column is marked to indicate that a report has been generated.
~his ensures that if a iurther count in that row reaches the
threshold another report is not generated.
- 31 -
~0.~ 20~ .
~ault reports are recorded in a cyclic buffer in ~lich
the row or column number and the appropriate a~ray (OCU or
periphera~) i9 recorded. The bufier i3 larg~ enough to ensure
that generally it does not overilow. If the queue i~ full then
the row or column iB not m~rked to indicate a report has been
generated, 80 that next time a report is received the threshold
will once again be seen to have been broken and another attempt
made to include the iault report in the c~clic buf~er etc.
Each report in the queue is allocated an appropriate re~erence
number. ~his enables easy reierence by the engineer. When a
new ~ault report i8 included in the queue an alarm is set o~.
Depending on which row or column is being reported ~ither a
prompt or deferred alaxm is ~enerated. When the enginesr
reque3ts the iault report list the alarms are ~emoved.
Every ~ hour the monitor un~t 6 receives reports fro= 'i
both tarifi peripheral equipment specifying the ~ hour (number
in range 0.95) and the date (day, month, year). Ii either
message received is in error (parity check) or the two reports
are more than 1 minute apart a iault report i8 gene~ated in
the same way as ior threshold counts.
Some details oi the connectio~ oi the CP~ monitor units,
such a~ 125 o~ ~igure 2, 204 of Figure 3, 304 oi ~lgure 4 and
405 oi Figure 5, to the monitor unit 6 are shown in Figure 7,
irom which it can be seen that the outputs irom the CPU monitor
units are stored in respective FIFO (fir t in, iirst out~
buffer~ 601 to 606 which are read by ~can ~ignals from a
- ~2 -
10~4Z09
monitor in~ut unit 611. ~he moni~or input unit~ 611 to 616
oach ino~ude a CP~ interiace 611A to 616 A for pre~entln~
the data received to the data processor of the monitor unit 6.
The operations oi the CP~8 in the peripheral units are
~imilar to that of the CP~ in an O~U as described above with
re~eren~e to Figure 2, in that they are divided into a number
of time elots ~hich are allocated respectively to ports
providing or requiring data. In the use of the peripheral
UnitB the port8 include the input/output unit~, the watch-dog
timer and the engineer'~ ~eys. The operations of the magnetic
cartridge recording units ali30 include the transfer of dats
to the magnetic recording unit~ and the checking of the data
to be recorded in each unit by reference to the data to be i`
recorded in the other unit. ~ecause the data rate which
magnetic recording units can handle is relatively low compared
with the speed of operation o~ the CP~, it is arranged that
.- when the magnetic recording units are ready to receive data
they interrupt the operation of the CPU and cause it to
transfer the data selected to the magnetic reco~ding units.
A typical routine ior a telephone switchboard operator
operating the equipment described above is as follows.
The method oi call arrival to the switchboard operator
will be unchanged and the operator will ani3wer the call as she
does at present. On accepting the call the operator will have
the "Ordinary" clas~ of service di6played, if the call has
originated from a coinbox line the operator is able to change
- 3~ -
lO9~Z()9
the class of service to "Coinbo~" by operation of a "coin box"
key. On operation of a "destination exchange/number~ key the
~DU in the OPE automatically displays the call tarifi period
in *orce. The "destination number" is keyed in national
signlficant number format and displayed on the YD~. On
operation of a "set destination" key a "stop time" key is
automatically operated and the required number i8 sent into
the network. The operator then records the originating e~change/
number, again in natiollal significant number format, and thi~
0 iB also displayed on the VDU. When the originating exchange/
number i8 recorded the call char~e step is automatically
displayed on the VDU. As soon a~ the operator has verified
that the call has been routed satisfactor~ly the "stop time" ~-
key i8 restored and an "automatic account" key may then be
operated prior to the operator leaving the connect circuit.
When the required number subsequently answer~, timin~ is started
automatically. At the end of the call, when both parties
clear, the connections are automatically released from the
switchboard and the call data, required to bring the call to
account, iB transferred to the magnetic tape cartridge leav~ng
the connect circuit free to accept a new call.
The tarifi period, charge step and originating line
class of service are di~played in ~eparate fields o~ the VD~
but the originating and destination numbers are displayed in
a common as~igned field. The control of the assigned field
is ~hared by a number of key~ and a mnemonic iB displayed in
- 34 -
1094Z(~9
the first space of that field to indicate which key has control.
When there are no keys operated, the assigned field displays the
destination number if such has been recorded. The equipment can
cater for an unlimited number of call procedures. Typical examples
are Freefone calls (i.e. calls charged automatically to the
recipient), credit card, transfer charge, personal, advise duration
and charge, and third party paying calls.
A substantial saving is envisaged in the operator
handling time on calls as the average delay between the operation
of keys and the display of data on the VDU is a fraction of a
second. Call details, once recorded, are used for both routing and
call recording purposes and can be used to make unlimited repeat
attempts in setting up connections on either side of the connect
circuit. The charging information, tariff rate and charge step,
is derived automatically from the originating and destination ex-
change national codes. Routing to the required exchange is achieved
where necessary by an automatic translation of the appropriate
exchange code.
Although the operator has the overall control of call
timing, in the majority of calls this will be undertaken automati-
cally. For most calls, when both parties have replaced their hand-
sets the equipment automatically performs its accounting function,
and releases the connections leaving the connect circuit free to
handle a new call. Normally once the operator has recorded all the
call details and set up to the destination exchange she need have
no further involvement in the call.
-35-
X
lO~Z()~
Although the invention has been described with reference
to a specific embodiment used for recording details of manually
connected telephone calls, it will be appreciated that it can
equally well be embodied in data processing equipment for other
purposes, such as, for example, airline seat reservations, banking
and insurance use and stockbroking transactions.
Other features of the embodiment described herein form
the subject of co-pending Canadian patent applications Nos.
273,123, 273,126 and 273,085 all filed on March 3, 1977. It will
be understood that the invention claimed in this application can
be used on its own or in conjunction with any of the inventions of
the above mentioned co-pending applications.
Other peripheral units than those described in the
particular embodiment may be added to or substituted for those
mentioned above. It will be appreciated that the number of units
and lengths of time intervals given are by way of example only and
these can be varied in any suitable manner.
-36-
- ~ - ,
'~
,
