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Description  |
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BACKGROUND AND SUMMARY
The present invention relates to electronic communication systems employing
existing telephone lines; and more particularly, it relates to a system
for quickly and conveniently transmitting data representative of an order
desired to be placed.
The present system is designed to be used in situations where a limited
number of known purchasers use the telephone to place orders with a
central location, especially when orders are placed frequently. An example
might be a number of hospitals ordering materials from a supplier. This
situation is distinguished from that of a retail catalog sales
organization taking orders from thousands of customers who may or may not
be repeat customers, but for the most part, do not re-order the same items
frequently, even if they are repeat customers.
One way in which the order taking from frequent repeat customers is
accomplished currently is simply that the orders are placed by a person
orally over the telephone to a remote, central location. If the operation
is large enough, the supplier may lease WATS lines from a number of larger
cities to reduce the cost of telephone order placement. Nevertheless,
because of the need to manually record the order at the central location,
and the need to place the order orally by the purchaser or "subscriber",
considerable expense is incurred just in the telephone usage.
There are existing systems which transmit data from remote locations or
subscribers to a central location through existing telephone communication
channels and using tone signals. One such system is disclosed in U.S. Pat.
No. 3,723,655 entitled "Credit Authorization System Terminal" in which
subscribers such as restaurants or stores transmit data to a central
processor which determines whether credit is to be authorized to a
customer. In this system, a telephone connection is established
automatically, and once the customer's identification data is transmitted,
the terminal operator uses a keyboard to enter the dollar amount of a
transaction, and the computer, upon receipt of all of the data, checks
stored data and transmits one of four possible display codes for the user
including (1) READY, that is, credit is accepted; (2) INCOMPLETE, that is,
re-execute the information; (3) CALL, indicating the terminal operator to
call the remote processor for explanation, or (4) DO NOT SELL, indicating
the customer's credit is not acceptable. This system does not offer the
flexibility and convenience of assembling an order from an existing set of
cards in an order deck, and transmitting the order to the central location
with acceptance or rejection signals returned as the information on each
card is verified, the "accept" tone being used to actuate the card reader
to read the next card. The credit card system is designed to read a single
card only and to transmit signals back to the subscriber representative of
a limited number of options which are displayed.
In U.S. Pat. No. 3,937,889, a data transmitter is capacitor-coupled to a
bridge tap at a subscriber's handset so that it is direct-wired to the
remote terminal telephone line. Data from transducers or keyboards is
transmitted at frequencies outside the voice band to the telephone central
office or to a central processor.
In U.S. Pat. No. 3,889,062, data terminals are coupled via telephone lines
to a central computer which controls the connection of an acoustic coupler
to a keyboard, a printer and the computer. U.S. Pat. No. 3,932,709
discloses a business telephone for the transmission and receipt of voice
messages and digital data which includes a computation mode wherein the
data terminal is electronically interfaced with the remote computer. U.S.
Pat. No. 3,505,474 discloses a portable computer terminal with an acoustic
coupler which sends and receives digital data in teletypewriter code to
and from a central computer. Data is transmitted by means of a keyboard,
and it is displayed through a printer at the remote terminal.
SUMMARY OF THE INVENTION
The present invention is directed to apparatus for communicating with a
central processor which is capable of returning "accept" or "reject"
signals in response to the reception of subsets of data (i.e., the data on
each individual card) received from subscribers. Each subscriber location
is provided with a card order deck comprising a number of individual
punched cards, each card bearing machine-interpretable data representative
of a known item to be ordered, for example. In a preferred embodiment, to
facilitate compatibility of the punched order code with the "2 of 7" code
in a tone signals encoder, each card has eight columns where apertures
might conceivably be punched. Thus, each row of eight bits comprises a
character. Seven bits are used to generate a "2 of 7" code used to actuate
a tone encoder when the keyboard is not being used, and the eighth bit is
used to indicate a "stop order" command. The last row on each card is
reserved, irrespective of the number of preceding items, for an
"End-of-Card" character, or simply, an EOC signal.
The operator selects the cards from the order deck corresponding to those
items and quantities which he desires to order at a given time, and he
places these order cards in a vertical stack in an input hopper of a card
reader. Thus, the stack may be modified or supplemented during data
transmission, if desired.
Initial communication is established through a conventional telephone
handset (rotary or pushbutton dial) with a remote central data processor.
In a dial tone dialing area, card dialing may be used, if desired, to dial
the number of the computer. In either case, the telephone handpiece is
placed in an acoustic coupler.
Once communication is established and the telephone handpiece is in place,
the operator at the subscriber station begins transmission of the order
data by actuating a "Manual Feed Switch" which causes the first card to be
read. This card contains customer identification data and a "Stop Order"
code. The feeding of cards is interrupted in response to the "Stop Order",
and data may be entered manually through a keyboard after an "accept" tone
indicates verification of the customer identification data. Such manually
entered information may be an order number. The keyboard may be a
conventional telephone dialing keyboard with 12 push buttons arranged in
four rows and three columns. A "2 of 7" code is used to signify a
character including one row signal and one column signal, as is done in
conventional telephone tone dialing systems. After the manual data is
entered and accepted, the operator initiates automatic card reading in
sequence.
The input signals, whether received from photodetectors reading the cards
or from the keyboard are coupled to pulse forming networks for shaping the
pulses, and the resulting signals are used to set corresponding latch
circuits. The outputs of the latch circuits are coupled to a conventional
"2 of 7" tone signal encoder which generates the tones transmitted to the
computer through the acoustic coupler, local telephone hand set and
established link. Reset circuitry comprising a loop senses the outputs of
the latch circuits and actuates a timer circuit which, after a lapse of
predetermined time, resets the latch circuits, thereby ending the tone
being transmitted. Thus, the duration of tones transmitted has a
uniformity and is independent of errors in the card transport mechanism,
for example.
When the information is received, the computer sends back either an
"accept" or a "reject" signal. Preferably, these signals are also tones.
If an "accept" tone is received by the subscriber, after an EOC signal has
been sent and provided a "Stop Order" code has not been detected by the
reader, a FEED signal is generated and coupled to the card reader to cause
the next card to be read.
A local loudspeaker is connected to the microphone in the acoustic coupler
by means of a switch which is actuated when the telephone handpiece is
placed in the coupler so that both the transmitted and the received tones
may be heard as they occur. This gives the operator an audible indication
that the system is working.
If the operator wants to transmit additional information manually, he may
do so either before he presses the FEED button to commence automatic
reading of cards, or between the reading of any two sequential cards (by
pressing a STOP button) or after the last item card has been read but
before an End-of-Order card (explained further below) is read.
If a "reject" signal is received from the central processor, the operator
may enter data manually via the keyboard, or he may re-run the card not
accepted, or he may simply skip the rejected card by actuating a manual
feed switch to manually generate a card feed signal and continue
subsequent automatic operation.
After all the individual order cards are read, and the information is
transmitted, an End-of-Order card is read, having been placed on the top
of the stack by the operator. This will notify the central data processor
that the order is completed, and upon receipt of a final ACCEPT tone, the
telephone handpiece is removed from the acoustic coupler on the operator
and returned to its cradle, and transmission is terminated.
The system includes other signal indicators, such as visual indicators and
audible alarms to facilitate detection of alarm conditions or to indicate
the status of the system; but these are best understood in light of the
complete circuit description.
The present system thus provides for the sequential transmission of data
prepared on punched cards wherein each card represents a separate order
item so that a complete order can be prepared by selecting cards. The
system takes advantage of existing telephone lines and is completely
compatible with them; yet it greatly reduces the time of use of such lines
when compared with the oral transmission of orders. Further, once the
order information is transmitted, it is already in a form readily
acceptable to a computer so that card-punching on the receiving end is
unnecessary and the computer may directly prepare a printout and order
verification form if desired.
Other features and advantages of the present invention will be apparent to
persons skilled in the art from the following detailed description of a
preferred embodiment accompanied by the attached drawing wherein identical
reference numerals will refer to like parts in the various views.
THE DRAWING
FIGS. 1A and 1B together comprise a function block diagram of a system
incorporating the present invention; and
FIG. 2 illustrates a typical card used in the system.
DETAILED DESCRIPTION
An optical card reader 10, such as is disclosed in application Ser. No.
804,883, filed June 9, 1977, for "Optical Card Reader Apparatus", of
Eitzen, et al, which is incorporated herein by reference, processes the
cards sequentially.
Briefly, the card reader 10 includes a supply hopper in which is placed a
stack of cards 11 (such as the one designated in FIG. 2), selected from an
order deck according to the items desired to be purchased, and they are
stacked vertically in the supply hopper, thereby facilitating modifying or
adding to the order during processing. The cards are fed from the bottom
of the stack by means of a plunger which is actuated by a card feed
solenoid (see reference numeral 13 of FIG. 1B). Each of the cards is then
passed in sequence by a card transport over an array of photodetectors or
sensors which are spaced laterally apart at a distance corresponding to
the spacing of the columns on the card 11. These photodetectors are
represented by the sensors 14-21 in FIG. 1A. A source of light is arranged
on the side of the card opposite the sensor so that the sensor is actuated
when an aperture in the card passes over it and the light
(diagrammatically indicated by the wiggly arrows into the sensors) is
incident on the active area of the photosensor. The sensors are also
activated between the time the feed solenoid is energized and the time the
leading edge of a card covers the sensors, and circuitry is included to
account for this since it conveys no information.
The card 11 may be of white opaque vinyl acetate, having a thickness of
0.030 inches. A notch 22 is located in one corner to provide correct
orientation in the supply hopper. Holes are punched in a matrix having
eight columns (running top to bottom in FIG. 2) spaced 0.2 inches apart;
and space is provided for 19 rows running side-to-side and spaced 0.2
inches apart along the length of the card.
A numeric code is used to symbolize information on the card including
numerals 0 through 9 which are represented by punching two out of seven
possible holes in the first seven columns starting from the right side of
the card. This 2 of 7 code corresponds to the same code on a conventional
12-station telephone keyboard, such as the one designated 25 in FIG. 1A
which is used for manual entry of data into the system.
Referring back to the card of FIG. 2, the eighth column is reserved for a
special "stop order" character which inhibits subsequent automatic feed
operation. The last character of each card comprises holes punched in the
fourth and seventh columns (locations R4 and C3) designating an
End-of-Card (EOC) signal. A portion of the card is reserved for written or
printed information to identify readily what is contained on the card. The
code of apertures on the card 11 is related to the code generated by the
keyboard 25 as follows. The keyboard 25 has four rows (R1, R2, R3 and R4)
and three columns (C1, C2 and C3). The first seven columns of the card 11
are designated R1, R2, R3, R4, C1, C2 and C3 respectively. When one of the
12 keys on the keyboard 25 is depressed, two switches are closed
corresponding to one row and one column. Associated with the four rows of
the keyboard are four continuous wave signal generators or oscillators,
each of a different frequency; and similarly, three frequency generators
are associated with the three columns. When one of the keys is depressed,
two switches are closed, actuating circuitry controlling the respective
frequency generators as explained below. Mixing of the two selected
frequencies yields a tone signal such as is used in standard telephone
dialing. Twelve combinations of frequencies are possible including the ten
numerals 0 through 9 and two contrl functions, conventionally represented
by the asterisk (*) and the pound or space (#) symbols.
Referring now to FIG. 1A, each of the sensors 14-21, in order to be
operative is fed an "Enable" signal along a line 26 from a sensor control
circuit 27 which may be a flip-flop circuit. The sensor control circuit 27
receives two inputs-- an "Enable" input designated F, and an inhibit
input, both of which will be more fully described below.
The output signals of the first seven sensors 14-20 are connected
respectively to pulse former circuits 30-36. The pulse former circuits are
conventional circuits designed to eliminate transients such as might be
caused by contact bounce and to establish a definite binary output signal
level.
The output signals R1 through R4 of the keyboard 25 are coupled
respectively in parallel with the sensors 14-17 to the pulse formers
30-33; and the column output signals C1-C3 of the keyboard 25 are coupled
in parallel respectively with the column sensors 18-20 to the inputs of
the pulse formers 34-36 respectively. Although not shown, the circuits may
be used to electrically isolate the keyboard outputs from the sensor
outputs, but a logical "OR" function is performed with the associated
pairs of outputs, as illustrated diagrammatically.
Thus, for each character entered, whether it is entered by means of the
card reader or the keyboard 25, the pulse former circuit 30-36 transmit
two "low" or "0" signals and five "high" or "1" signals.
The output signals of the pulse formers 30-36 are connected respectively to
the set input terminals of latch flip-flop circuits 37-43 respectively;
and the complementary or Q outputs of the latch circuits 37-43 are
connected to the seven input terminals of a tone signal encoder 45 which
is a commercially available crystal controlled integrated circuit module
manufactured by Motorola, Inc. under the designation MC14410, which
produces a predetermined tone signal (two frequencies mixed) when a ground
potential is established on any two of its eight input terminals (only
seven of which are being used in the illustrated embodiment). Since the Q
outputs of the latches 37-43 are normally at a logical high potential,
these output terminals may be connected directly to the tone signal
encoder 45. Thus, insofar as the latch circuits 37-43 and the tone signal
encoder 45 are concerned, it makes no difference whether the information
was generated by the card reader or the keyboard 25.
The output of the tone signal encoder 45 is coupled via line 45A through an
operational amplifier 46 (FIG. 1B) and a transformer 47 to a speaker 48 in
an acoustic coupler 50. The acoustic coupler 50 is designed to receive a
telephone handpiece 51 including a transmitter 52 and receiver 53. The
sound from the speaker 48 of the acoustic coupler 50 is coupled to the
transmitter 52 of the handpiece 51; and the tone signals are thus
transmitted over telephone lines 54 to a data processor 55 which may be
centrally located relative to a number of subscribers of the type being
disclosed herein.
Thus, by way of summary, when any two input terminals of the tone encoder
45 are energized with a relatively low voltage or ground from two of the
latches 37-43, a tone is generated and transmitted until the two latches
are reset to drive the input terminals of the tone encoder to a relatively
high voltage. In order to make the tone time uniform, reset loop circuit
means are provided including a first NAND gate 58 having four inputs
received respectively from the Q outputs of the latch circuits 37-40 and a
second NAND gate 59 having three inputs received respectively from the Q
outputs of the latch circuits 41-43. The output signals of the NAND gates
58, 59 are coupled by lines 58A and 59A respectively to the two inputs of
a NAND gate 60. The output of the NAND gate 60 is coupled through a pulse
former circuit 61, similar to those already described for generating a
constant level output, to a tone duration timer circuit 62 which may be a
conventional monostable circuit responsive to an input signal for
generating an output signal of constant time duration. The output of the
tone duration timer circuit 62 is coupled through a pulse former circuit
63 and a line 63A to the reset input terminals of the latch circuit 37-43
of FIG. 1A. Thus, the trailing edge of the pulse from the tone duration
timer circuit 62 is used to reset all of the latch circuits 37-43 to their
reset states a predetermined time after the coincidence of two tone
selection signals, one representative of a selected row and the other
representative of a selected column in the keyboard matrix or the card
sensor system.
The acoustic coupler 50, in addition to the speaker 48 includes a pick-up
microphone 65 which senses the side-tone in the handset 51 during the
transmission of signals, and transmits the tone through a pre-amplifier 66
to a saturated amplifier 67 and a power amplifier 68. The power amplifier
feeds a loudspeaker 69 through a normally open switch 69A so that the
operator at the subscriber can hear whether tones are being transmitted
through the handset 51. The switch 69A is located under the receiver
bracket, and it is closed when the telephone handset is placed in the
acoustic coupler. This avoids acoustic feedback which would otherwise
cause audible oscillation if the handset were not in the acoustic coupler.
A manual volume control 68A may be provided to adjust the gain of the
power amplifier 68 to control the volume output of the speaker 69. Thus,
all of the signals to and from the remote central processor 55 are also
audible to the operator at the remote subscriber by means of the
loudspeaker 69.
When the data is transmitted to the central data processor 55 for each
card, the central data processor returns one of two tone signals: an
"accept" tone or a "reject" tone. These signals are coupled through the
microphone 65, pre-amplifier 66, and saturated amplifier 67 to a line 67A
which is connected to the inputs of an accept tone decoder 70 and a reject
tone decoder 71 (FIG. 1A). The tones are also heard over the loudspeaker.
The tone decoders 70, 71 are conventional phase-locked loops which
function as bandpass filters, the bandwidth being a function of input
signal amplitude. The accept tone decoder 70 is, of course, tuned to the
"accept" tone frequency received from a central data processor 55 and the
reject tone decoder 71 is similarly tuned to the "reject" tone frequency.
The output signals (FIG. 1A) of the accept tone decoder 70 (through a delay
circuit 70B) and the reject tone decoder 71 are coupled by means of lines
70A and 71A respectively to the inputs of pulse former circuits 73 and 74
in FIG. 1B. These pulse formers are similar to the ones already discussed,
and their outputs are connected respectively to the set input terminals of
latch circuits 75, 76.
In the case of a reject tone, the Q output of the flip-flop 76 is coupled
to a "Card Reject" indicator lamp 78 and through OR gate 122A to the input
of an alarm oscillator circuit 79 which generates a continuous,
fixed-frequency signal which is coupled through an alarm modulator circuit
80 to the amplifier 68, and ultimately to the loudspeaker 69 from which it
is heard as a periodically intermittent audible tone, clearly recognized
as an alarm signal. The alarm signals, both audible and visual, may be
turned off by means of a reset switch 83 which is a manually actuated
switch for resetting the flip-flop 76. This manual reset signal is also
coupled through a line 83A and an OR gate 85 (FIG. 1A) to the inhibit
input of the sensor control flip-flop 27 to permit the operator to
manually enter data into the system by means of the keyboard 25, if he
desires.
Automatic Card Feeding
In order to continue in the automatic card feeding mode, three conditions
are required. These three conditions are represented by electrical signals
presented to the three inputs of a NAND gate 87 in FIG. 1B. One of the
signals, received from the previously described latch flip-flop 75
represents the detection of an "accept" signal from the central data
processor. This indicates that the information previously transmitted to
the central data processor has been accepted following an EOC character of
a previously read card.
The second condition necessary for feeding the next card is that the
previously read card be sufficiently clear of the bottom of the deck as to
permit the next card to be fed into the card transport. The holes R4 and
C3 representing the EOC character in FIG. 2 are always punched at a
predetermined location on the card 11. This information together with the
known feed rate of the cards, the desired spacing between consecutive
cards, and the time interval required after the detection of and EOC
character, will determine the initiation of feeding of the next card.
Due to the inherent differences in sensor response time and the possibility
that the leading edge of a card may not be truly parallel to the axis of
the sensor array, errors may arise as the leading edge of a card passes
over the sensors such that the eight sensors do not all become inactive
simultaneously. If the two positions corresponding to the EOC character
are the last to become inactive when a leading edge of a card crosses the
sensors, it is possible to generate a false EOC signal. Further, it will
be appreciated that all sensor positions are illuminated in the interval
between cards. Hence, provision is made to insure that an error does not
occur by connecting the output R3S of sensor R35 directly to an
End-of-Card detector 92, which may be a NAND gate. A time delay circuit 91
receives the output of the AND gate 90 and is coupled to the other input
of an End-of-Card detector 92. The Q outputs R4H of the latch 40 and C3H
of latch 43 are coupled to the inputs of AND gate 90. Following the
voltage levels through the circuitry being described, the output terminals
of the sensors 14-21 are normally biased at a positive or "high" level
through a bias resistor, one of which is shown at RB in FIG. 1A. The
output actuating signal 26 from the sensor control flip-flop 27 is a "low"
or ground signal. Hence, when a sensor is energized by incident light
energy, its internal resistance becomes relatively low and its output
signal is a negative-going spike. Polarity is not reversed in the pulse
former circuits, and the latches are set on a negative leading edge. Thus,
the signals R4H and C3H are positive when an EOC character is being read;
and similarly, the R3S signal is positive only when the Row 3 sensor is
not being illuminated, indicating that a true EOC character is being
sensed, not the interval between cards when all sensors are illuminated.
This EOC signal is coupled to a Card Transit Timer circuit 94, the output
of which is coupled by means of line 94A to a pulse former 95 on FIG. 1B
and thence to the set input of a latched flip-flop 96, the Q output of
which forms the second input of the NAND gate 87. The function of the Card
Transit Timer 94 is to delay the transmission of the EOC signal to the
latch 96 for a predetermined time to allow the card being read to pass
from the card reading station and to permit a desired interval before
feeding the next card.
The third input of the NAND gate 87 is a signal which is designed to insure
that a "Stop Order" signal has not been generated. A Stop Order is sensed
by the eighth (i.e., left-hand column in FIG. 2) position sensor 21, and
its output signal is fed to a time delay circuit 100 which performs a
function similar to that of the previously discussed time delay circuit
91, which is to avoid errors which would otherwise be caused by the
misalignment of the leading edge of a card or by sensor response
differences. The output of the time delay circuit 100 is fed to an
inverter circuit 101, the output of which feeds a NAND gate 102. The other
input of NAND gate 102 is received from a time delay circuit 103, the
input of which is the signal R3S. Tus, the output of NAND gate 102 is a
signal representative of the fact that the Stop Order sensor 21 has been
actuated and that at least one other sensor (whose signal has been
momentarily delayed by the time delay circuit 103) is inactive. This
insures that only the stop sensor is actuated; and the resulting stop
order signal is transmitted along a line 102A through a pulse former 105
(FIG. 1B) to the set input of a latch circuit 106. The Q output of the
latch circuit 106 is fed as the third input of the NAND gate 87. The Q
output of the latch circuit 106 is directly connected to a stop order
indicator lamp 107 to provide a visual signal that a Stop Order has been
sensed.
A Stop Order signal may also be initiated manually by means of a switch 109
(FIG. 1A) which is coupled to the output of the NANd gate 102--namely, the
line 102A.
To summarize, the NAND gate 87 generates a signal which indicates first,
that an EOC signal had been detected from a previously read card;
secondly, that the information on that card had been accepted by the
central data processor and an "accept" tone had been received; and
thirdly, that a "Stop Order" signl had not been generated. When these
conditions occur, the output signal of the NAND gate 87 is fed through a
pulse former cirucit 110 to a feed solenoid timer circuit 111. The output
of the feed solenoid timer circuit forms a signal denoted F which also
forms the enable signal input of the sensor control flip-flop 27 shown in
the upper left-hand portion of FIG. 1A. The feed solenoid timer generates
an output signal for a predetermined time sufficient to feed the next card
from the bottom of the input hopper of the card reader so that it is
picked up by the card transport mechanism, described in the
above-referenced application. This signal is fed to energize a relay 115
which, in turn, actuates the previously described card feed solenoid 13.
Card feed can also be initiated manually be means of a manual feed switch
116 which energizes the feed solenoid timer 111.
If a card fails to feed over the sensor array, or if the card supply hopper
becomes empty and the operator had neglected to include a "Stop Order"
code, circuitry is provided for alerting the operator. This circuitry
includes a time delay circuit 120 (shown in the center right side of FIG.
1B) which is actuated by the feed signal F. The output of the time delay
circuit 120 feeds one input of an OR gate 121. The other inputs of the OR
gate 121 are received respectively from the Row 3 Sensor, R3S previously
described and from the output of the Stop Order sensor 21. This signal is
designated ST.
The output of the OR gate 121 is connected to the set input of a latch
circuit 122; and the reset input of this latch circuit is received from
the reset switch 83, the line being designated 83A on the left margin of
FIG. 1B. The Q output of he latch circuit 122 is connected to a feed
failure lamp 123 to energize it, and it is also connected through OR gate
122A to the input of the alarm oscillator 79.
The circuitry just described operates as follows. When the feed solenoid
timer 111 completes its time, the time delay circuit 120 is actuated to
allow a preset time for a card to be read. If, at the end of the time
delay determined by the time delay circuit 120, the Row 3 sensor and the
order sensor are still illuminated, it indicates that no card is
positioned above the sensor array since the two signals cannot occur at
the same time unless all sensors are being energized by the incident
light. Thus, a signal will appear at the output of the OR gate 121 to set
the latch 122, thereby energizing the feed failure lamp 123 and the
periodically intermittent audible alarm, described above, which is sounded
through the loudspeaker 69. The latch 122 may be reset by the manual reset
switch 83, thereby terminating the alarm signal. The feed solenoid timer
energizes the feed solenoid for a predetermined time. Although not
illustrated, an "Automatic Feed" indicator lamp may be energized by the
output of pulse former 110 and a "Manual Feed" indicator lamp may be
energized by the Manual Feed Switch 116 to inform the operator of the mode
of operation.
Operation
The user at the subscriber selects cards from a large file or order deck,
for example, up to 100 items may be ordered at one time. A customer
identification card containing a "Stop Order" code is included as the
first card in the stack and an "End-of-Order" card is added as the last
(top). The stack is placed into the input hopper of the card reader 10,
which is running. The customer places the handset in the acoustic coupler
and dials the number that will connect the subscriber station with the
central data processor. A tone heard over the loudspeaker indicates that
the processor is on line. If the processor is inoperative, a voice
recording may be transmitted indicating an estimate of the time at which
serve will be restored. Next, the operator actuates the manual feed switch
116 which causes the customer identification card to be read by actuating
the card feed solenoid 13. The information detected by the sensors 14-20
is stored in the latches 37-43 and encoded by the dial tone encoder 45.
Corresponding tone signals are transmitted from the speaker 48 through the
telephone pick-up 52 to the central data processor until the "Stop Order"
character is detected in the sensor 21. Upon this detection, and since the
card is still covering the sensors (that is, signal R3S is positive), the
NAND gate 102 will generate a signal along line 102A to cause latch 106 to
be set, thereby disabling NAND gate 87, and interrupting the automatic
feeding of cards.
The computer verifies the identification and if it is correct, returns an
"accept" tone, which is detected at the pick-up microphone 65 of the
acoustic coupler 50 and fed through the pre-amplifier 66, the amplifier 67
and the line 67A to the accept tone decode 70. The output signal of the
accept tone decoder 70A causes the latch 75 to be set. The customer then
dials a purchase order number on the keyboard 25 and whatever other
information may be necessary for his records, and again awaits
verification from the central data processor. Upon hearing an audible
"accept" tone from the data processor, he again presses the manual feed
switch 116, thereby actuating the card feed solenoid 13 and the first item
order card is fed through the card reader 10. Alternatively, upon hearing
the "accept" signal, he has the option of entering, at the start of an
order, information that had not been included in his order stack. This
information would be entered by the keyboard 25.
Each card contains an EOC character, and as it is detected in the
End-of-Card detector 92, the card transit timer 94 is actuated to set the
latch 96 after a predetermined time has lapsed, insuring the complete
reading of the card. It will be observed that the previous feed signal F
had reset each of the latches 96, 75 and 106. The latch 106 had been set
prior to this time because a stop signal had not been received. Further,
the latch 75 had been set because an "accept" tone had been received and
decoded in the accept tone decoder 70, provided no errors had been
detected or occurred. The delay circuit 70B delays the "Accept" signal for
a time at least as long as the duration of the accept tone to prevent
transmission coincidence with the actual accept tone.
If the customer desires, a Stop Order character may be used at the end of
the end-of-order card of an order prior to the end-of-card signal. This
will be detected by the Stop Order sensor 21 and associated circuitry
described above, and the resulting signal from the NAND gate 102 is used
to set the latch 106, thereby inhibiting the NAND gate 87, so that a final
alarm tone will be prevented.
If an error occurs and is detected, due for example, to problems such as
damaged cards, incomplete order data, improperly punched cards, or a
discontinuity in telephone transmission, the data processor will transmit
a "reject" signal. This signal, which could occur after any EOC signal, is
detected in the reject tone decoder 71 which sets the latch 76 (FIG. 1B),
thereby actuating the alarm indicator lamp 78 and an audible alarm
transmitted via the loudspeaker 69. At the same time, it inhibits the
generation of the next subsequent F feed signal because the latch 75
remains reset and is not set--thereby inhibiting the NAND gate 87.
In one embodiment, the data processor may be programmed to stand by for a
predetermined time, for example 30 seconds, awaiting corrective action by
the ordering subscriber. The corrective action may include manual
retransmission of correct data or removal of the defective order card and
manually re-starting the card reader. If corrective action is not taken
within the prescribed time, the computer may disconnect the telephone line
and erase the portion of the order already received.
Commercial tone dialing signal reception equipment requires that the
duration of each tone signal burst last for at least 0.055 seconds, and
that the interval between tone bursts be at least 0.045 seconds. Thus, the
maximum reading rate is 10 characters per second. The maximum velocity for
a card having its aperture rows separated by 0.2 inches is 2 inches per
second. In one embodiment, where the card is 51/2 inches long and the
cards are spaced 1/2 inch apart in being fed to the reader, a maximum read
rate of three seconds per card is allowed. This has been found to provide
a reasonble rate, but requires that a subsequent card not be fed until the
preceding card has advanced beyond the point to which the subsequent card
will be moved by the card feed plunger. To meet this requirement, the card
transit timer 94 is used to inhibit the operation of the card feed plunger
for the required interval after an EOC signal is detected.
Having thus described in detail a preferred embodiment of the invention,
persons skilled in the art will be able to modify certain of the structure
which has been disclosed and to substitute equivalent elements for those
described while continuing to practice the principle of the invention; and
it is, therefore, intended that all such modifications and substitutions
be covered as they are embraced within the spirit and scope of the
appended claims.
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