Fuel dispenser electronics design

A fuel dispenser for installation in a service station equipped with a dispenser control console includes a housing, a pump to pump fuel through the housing, a fuel flow meter in the housing, a switch actuable to indicate fuel is to be pumped through the housing, a display on the housing to display the amount of fuel pumped through the housing, and a dispenser control. The dispenser control includes a plurality of microcontroller nodes and a communications bus connecting the microcontroller nodes. A first node is associated with the switch, pump and fuel flow meter, a second node is associated with the display, and a third node is associated with a data link to the dispenser control console. A user may indicate fuel is to be pumped by actuating the switch and generating a signal to the first node, with the first node activating the pump and communicating fuel amount data onto the communications bus, the second node responding to fuel amount data on the bus to display the amount of fuel pumped, and the third node generating a signal to communicate the fuel amount data to the dispenser control console.

BACKGROUND OF THE INVENTION 
The present invention relates to improvements in fuel dispenser electronics 
design. More particularly, the present invention provides a local 
operating network for a fuel dispenser to permit modular design and 
construction with minimal wiring and no unused components. 
Modem fuel dispensers use microelectronics to assist in carrying out the 
dispenser's functions of pumping and dispensing fuel, recording the amount 
sold, and providing, in some cases, convenient credit or debit card 
payment options. Often, these latter features have been add-ons to 
pre-existing dispenser designs, with the result that the dispenser 
interior may have extensive wiring and cabling for power and control 
signals, which promotes the possibility of various errors occurring. 
Usually, a single microprocessor has primary dispenser control, as seen in 
dispenser 10 in FIG. 1. Cabling and wiring emanates from a central 
microprocessor 26. The central microprocessor 26 may be of the model known 
as Z80. 
Many modem dispensers can be approached from two sides, each by a customer 
fueling his or her vehicle, so dispensers include side A and side B 
capabilities to service these customers. The wiring and cable emanating 
from the microprocessor 26 includes hardware I/O cable 13 leading to side 
A main display 12 and its associated price posting units 14. The hardware 
I/O line 13 also leads to side B main display 16 and its price posting 
units 18. Power to the microprocessor 26 is obtained through an AC input 
20 fed through a power supply 22 and a main regulator 24 to provided a 
regulated DC supply along line 28. 
Some dispensers have a programmable pump preset, which turns the pump off 
after a certain amount of fuel has been dispensed. In dispensers of this 
type, a preset 30, often a Z80 microprocessor, has a serial interface 32 
to the microprocessor 26. 
The microprocessor 26 also receives data along the hardware I/O line 34 
from a manager keypad 36. The manager keypad is a small keyboard located 
inside the electronics portion of the dispenser. It is used for pump 
programming and certain diagnostic functions. Access to this keypad is 
restricted to authorized personnel via a locked door and provides up to 
three levels of security codes. Accordingly, the information communicated 
along line 34 can be quite complex. 
The microprocessor 26 also receives data from the hardware I/O line 42 from 
a hydraulic interface 40 which, in turn, has wiring and cabling to a 
number of spaced-apart units 38 including pump handles, submerged turbine 
pumps, valves and the pulsers of the dispenser. The pump handles are the 
units on the outside of the dispenser on which nozzles usually rest and 
which are raised by the customer to indicate that fuel is to be dispensed. 
The submerged turbine pumps are located, typically, in underground storage 
tanks at the end of a supply conduits and actually provides the function 
of forcing the fuel to be dispensed through the supply conduits and the 
dispenser. The various valves involved control the flow of the liquid as 
required. Pulsers are known units in fuel dispensers. Pulsers are 
connected to meters which are forced to rotate by the flowing fuel. The 
rotation of the meter drives the pulser to output electrical pulses 
corresponding to the volume of liquid being dispensed. Typically, each 
pulse represents one/one-thousandths of a gallon. The foregoing 
description applies to the multi-product dispensers, which are now 
commonplace. Not shown in FIG. 1 is the possibility of a different 
hydraulic interface 40 and series of pumps and valves 38. If the dispenser 
is a blending dispenser such as is shown in U.S. Pat. No. 5,029,100 to 
Young et al.; U.S. Pat. No. 4,876,653 to McSpadden et al.; or U.S. Pat. 
No. 4,978,029 to Furrow et al., all owned by Gilbarco, the assignee of 
this application, a different control configuration to cause different 
grades of fuel to be blended as they are dispersed will be desired. The 
entire disclosure of these patents is incorporated herein by reference. 
Also as seen in FIG. 1, the microprocessor 26 has a two-wire connection 46 
to additional devices in some embodiments. Thus, as shown in FIG. 1, a 
side A card reader in dispenser (CRIND) logic module 44 is connected to 
card reader peripherals 48. The peripherals may include a card reader for 
reading the magnetic stripe on a credit or debit card, a printer to print 
receipts, a display associated with the card reading and printing process, 
and a note or currency acceptor for receiving currency. Other types of 
payment arrangements can also be used, such as the debit card arrangement 
disclosed in U.S. patent application Ser. No. 08/160,936, now abandoned 
filed Dec. 2, 1993, of Kaehler, the entire disclosure which is hereby 
incorporated by reference. Side B card reader logic module 50 and side B 
card reader peripherals 52 are also provided, similar to Side A. 
Typically, the card reader logic module 44 will have communications 
capability over a line, such as a twisted pair 54 to a service station 
site controller. This is necessary in order to validate credit cards, and 
the like. In this regard, the communication may be encrypted, as disclosed 
in U.S. Pat. No. 5,228,084 of Johnson et al., entitled "Security Apparatus 
and System for Retail Environments", the entire disclosure of which is 
incorporated herein by reference. Similarly, card reader and personal 
identification number input devices and protocols as described in U.S. 
Pat. No. 4,967,366 of Kaehler entitled "Integrated Gasoline Dispenser and 
POS Authorization system with Unattended PIN Pad" may be used, and the 
disclosure of that patent is incorporated herein by reference. 
The net effect, as seen in FIG. 1, is that the microprocessor 26 has 
numerous inputs and communication capabilities to the various components 
of the dispenser 10. As the central hub, the processor 26 monitors many 
inputs and controls many outputs. It is also responsible for many internal 
operation controls and calculations. This design suffers a limitation on 
the number and kind of feature options such as the displays, card readers 
and printers that can be added to and controlled by the single computing 
element. Also, by having each component tie back to the central processor, 
the number of cables required in dispensers increases, and it also adds to 
the level and complexity required in the microprocessor 26. This is 
further complicated by the need to supply power to the devices, such 
additional power supply wiring connections are not shown in FIG. 1. 
The manufacture of such a dispenser requires careful attention to detail to 
properly assemble wiring harnesses and connections. The cabling is 
time-consuming, and errors can easily occur. Therefore, there is a need in 
the art for an improved dispenser electronics design to minimize the 
number and complexity of wiring connections. 
SUMMARY OF THE INVENTION 
The present invention fulfills this need in the art by providing a fuel 
dispenser for installation in a service station equipped with a dispenser 
control console including a housing, a pump to pump fuel through the 
housing, a fuel flow meter in the housing, a switch actuable to indicate 
fuel is to be pumped through the housing, a display on the housing to 
display the amount of fuel pumped through the housing, and a dispenser 
control including a plurality of microcontroller nodes and a 
communications bus connecting the microcontroller nodes, a first node 
associated with the switch, pump and fuel flow meter, a second node 
associated with the display, and a third node associated with a data link 
to the dispenser control console. A user may indicate fuel is to be pumped 
by actuating the switch and generating a signal to the first node, with 
the first node activating the pump and communicating fuel amount data onto 
the communications bus, the second node responding to fuel amount data on 
the bus to display the amount of fuel pumped, and the third node 
generating a signal to communicate the fuel amount data to the dispenser 
control console. 
Preferably, the communications bus is a five wire bus having two data 
wires, a reset wire and two power supply wires for the nodes to provide 
electrical power to the nodes for use by their associated components. Each 
of the microcontroller nodes may include a network communication port, a 
read only memory storing a communications protocol, a memory storing 
application code suitable for that node, input/output pins and a 
counter/timer. 
In a preferred embodiment, the first node also controls a main valve. It 
may also control a slowdown valve. Preferably, the fuel flow meter 
includes a pulser that generates a pulse each time a predetermined 
quantity of fuel passes the meter and the first node converts the pulses 
to a volume of fuel datum that is communicated on the bus. The first node 
may also communicate a pulser fail signal on the bus if it detects failure 
of the pulser. 
Typically, the display includes displays of price per quantity, quantity 
dispensed and calculated price for the quantity dispensed and the second 
node supplies data for each of the displays. The second node may include a 
calculator to calculate the price for the quantity dispensed. 
Desirably, the third node is a pump state enforcer. 
In a preferred embodiment, the dispenser includes a manager keypad and the 
third node scans and interprets messages from the manager keypad. The 
third node may also generate the signal to communicate the fuel amount 
data to the dispenser control console and output the signal over a two 
wire link. 
The dispenser may also include a card reader for reading payment cards and 
a node associated with the card reader and communicating card data onto 
the communications bus. In such an embodiment, preferably the third node 
communicates card data to the console and receives card authorization data 
from the console. 
The dispenser may also include a printer in the housing and a node 
associated with the printer to print data derived from the bus. The 
dispenser may also include a note acceptor in the housing and a node 
associated with the note acceptor and communicating accepted note data 
with the communications bus. 
In one embodiment there are a plurality of pumps to pump different grades 
of fuel that are blended together, and the first node controls the 
plurality of pumps. In another embodiment the pump to pump fuel, fuel flow 
meter, and switch actuable to indicate fuel is to be pumped are provided 
in multiples, one of each for each grade of fuel to be dispensed, and a 
node like the first node is provided for each grade. 
A video display may be included in the housing and a node associated with 
the video display, for displaying indicia pertinent to data on the 
communications bus. 
Some fuel dispensers include active vapor recovery equipment and the 
invention can provide control for the active vapor recovery equipment with 
a node associated with the active vapor recovery equipment. 
The dispenser may include an auxiliary preset and a node associated with 
the auxiliary preset. 
The dispenser may include a temperature sensor and a node associated with 
the temperature sensor. 
The invention also provides a fuel dispenser including a housing, a pump to 
pump fuel through the housing, a fuel flow meter in the housing, a switch 
actuable to indicate fuel is to be pumped through the housing, a display 
on the housing to display the amount of fuel pumped through the housing, 
and a dispenser control including a plurality of microcontroller nodes and 
a communications bus connecting the microcontroller nodes, a first node 
associated with the switch, pump and fuel flow meter, a second node 
associated with the display, and a third node associated with program 
control node. A user may indicate .fuel is to be pumped by actuating the 
switch and generating a signal to the first node, with the first node 
activating the pump and communicating fuel amount data onto the 
communications bus, the second node responding to fuel amount data on the 
bus to display the amount of fuel pumped, and the third node providing 
data traffic management and diagnostic functions. 
The invention also provides a method of controlling fuel dispensers like 
those described above including generating a signal through one of the 
nodes onto the bus upon actuation of the switch, pumping fuel with the 
pump, communicating fuel flow data through one of the nodes onto the 
communications bus, reading data from the bus with a node to generate a 
display of the amount of fuel pumped, and providing data traffic 
management and diagnostic functions for the other nodes and communications 
bus with the control node. 
The method may also include supplying electrical power to the nodes over 
the communications bus for use by their associated components. 
In one embodiment the generating step and the communicating fuel flow data 
step may pass data through the same node. The method may include enforcing 
pump state by ensuring that proper control sequences have occurred to 
allow pump operation, the pump state enforcing step being performed by the 
control node. The reading data step may be followed by calculating the 
price for quantity dispensed, the calculating step being performed in the 
same node that generates the display of the amount of fuel pumped. In one 
embodiment the method includes communicating data of the amount of fuel 
pumped from the control node over a data link to a dispenser control 
console. 
The method may include reading card data in a card reader in the housing, 
and communicating card data from the control node with a data link to a 
dispenser control console. The method may also include accepting cash in a 
cash acceptor in the housing, and communicating cash data from the control 
node with a data link to a dispenser control console and/or delivering 
transaction data to a receipt printer in the housing from the 
communications bus through a node and printing a receipt in the receipt 
printer. 
The method may include delivering video display data to a video display in 
the housing from the communications bus through a node and displaying a 
video using the data. 
In one embodiment the pumping step includes pumping a plurality of 
different grades of fuel that are subsequently blended together, and 
controlling the plurality of pumps with a node to achieve a desired blend. 
For a dispenser having a pump to pump fuel, a fuel flow meter, a switch 
actuable to indicate fuel is to be pumped, and node for each grade of fuel 
to be pumped, the method may include generating a signal through a 
particular node onto the bus upon actuation of the switch associated with 
the grade to be pumped, pumping fuel with the pump associated with the 
grade to be pumped, and communicating pumped fuel flow data onto the 
communications bus, while keeping other ones of the pumps idle. 
For a dispenser having a pump to pump fuel, a fuel flow meter, a switch 
actuable to indicate fuel is to be pumped, active vapor recovery equipment 
and a node for each grade of fuel to be pumped, the method may include 
generating a signal through a particular node onto the bus upon actuation 
of the switch associated with the grade to be pumped, pumping fuel with 
the pump associated with the grade to be pumped, activating the active 
vapor recovery equipment, and communicating pumped fuel flow data onto the 
communications bus. 
For a dispenser having liquid fuel volume temperature compensation 
capability, the method may include, upon occurrence of the generating 
step, transmitting a liquid fuel temperature signal from a temperature 
sensor through a node onto the communications bus and thence through 
another node to permit compensation of the measured volume of fuel 
dispensed, to account for thermal expansion or contraction of the fuel. 
The invention further provides a method of controlling a fuel dispenser 
that has a housing, a pump to pump fuel through the housing, a fuel flow 
meter in the housing, a switch actuable to indicate fuel is to be pumped 
through the housing, a display on the housing to display the amount of 
fuel pumped through the housing, and a dispenser control including at 
least two microcontroller nodes and a communications bus connecting the 
microcontroller nodes, one of the nodes being associated with one of the 
switch, pump, fuel flow meter, display. The method includes signaling a 
first network variable through one of the nodes onto the bus upon 
actuation of the switch and storing the first network variable on another 
node, pumping fuel with the pump, communicating a second network variable 
pertaining to fuel flow from one of the nodes onto the communications bus 
and storing the second network variable on another node, and using the 
second network variable to generate a display of the amount of fuel 
pumped. A network variable is a data packet or data transmission over the 
bus between nodes. 
The invention provides numerous benefits. There are reductions in materials 
costs in that the distributed architecture lends itself to distributed 
power regulation. This requires, therefore, fewer cables and connectors 
for the electronics assembly. 
There are reduced manufacturing costs using the present invention. There 
are fewer cables to connect, resulting in faster assembly with fewer 
misconnections. The design according to the present invention eliminates 
the configuration jumpjacks which have previously been used on display 
boards. The nodes can also be programmed to have the ability to self-test 
each other for defects. 
The software used with the present invention is of decreased complexity 
since it is distributed into functional modules instead of being 
concentrated in a central high level processor. 
The invention provides scalability from low end to high end models of 
dispensers, with no unutilized components being packaged in any assembly. 
The plurality of processors in the local operating network design can 
provide service technicians with increased resident diagnostic functions, 
therefore making it easier to service units in the field and quickening 
the mean time to repair. 
The design also provides increased packaging flexibility of the components 
in a dispenser. The nodes can be placed on or next to the devices which 
they control. 
The invention also permits easy add-ons, including the possibility of 
automatic reconfigurations as options are added. The invention also 
provides the ability to add future options easily, including options not 
contemplated at the time of original manufacture. 
Also, the modular aspect of the local operating network permits the design 
to be refined for different needs, including the needs of different 
standards in different countries.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In contrast to the central, controlling microprocessor used in the 
dispenser depicted in FIG. 1, the present invention provides distributed 
processing with multiple microprocessor nodes. A preferred embodiment uses 
serial protocol and hardware and software made available by Echelon 
Corporation, 4015 Miranda Ave., Palo Alto, Calif. 94304. The various 
components available from Echelon Corporation usable in connection with 
the invention and in establishment of the preferred embodiment are a 
neuron 3120 chip, a neuron 3150 chip, a LonBus communications bus and a 
LonTalk protocol for networking the chips together. 
Additional information concerning the Echelon system is available in the 
following U.S. patents and PCT patent publications of Echelon: 
______________________________________ 
Pat. No. Title 
______________________________________ 
Protocol Patents 
4,941,143 Protocol for Network Having a Plurality of 
Intelligent Cells 
4,947,484 Protocol for Network Having a Plurality of 
Intelligent Cells 
4,955,018 Protocol for Network Having a Plurality of 
Intelligent Cells 
4,969,146 Protocol for Network Having a Plurality of 
Intelligent Cells 
4,018,138 Protocol for Network Having a Plurality of 
Intelligent Cells 
WO 92/010041 
Multi Access Carrier Sensing Network 
Communication Protocol with Priority Messages 
5,249,270 Development System Protocol 
5,297,143 Network Communication Protocol Including 
a Reliable Multi Casting Technique 
Neuron Chip Programming Language, Binder and 
Network Variables 
WO 92/16905 
Programming Language Structures for Use 
in a Network for Communicating, Sensing and 
Controlling Information 
WO 92/16904 
Binder Interface Structure 
WO 92/16895 
Network Variables 
Network Collision Detection Technology 
WO 93/06670 
Methods and Apparatus for Preventing 
Unnecessary Retransmission of Messages in a 
Network Messaging System 
Neuron Chip Transceiver Interface 
5,182,746 Transceiver Interface 
Local Operating Network Technology 
4,918,690 Network and Intelligent Cell for Providing 
Sensing, Bidirectional Communications and 
Control 
4,939,728 Network and Intelligent Cell for Providing 
Sensing, Bidirectional Communications and 
Control 
4,969,147 Network and Intelligent Cell for Providing 
Sensing, Bidirectional Communications and 
Control 
5,034,882 Multiprocessor Intelligent Cell for a Network 
which Provides Sensing, Multi-directional 
Communications and Control 
5,113,498 Input/Output Section for an Intelligent Cell 
Which Provides Sensing, Bidirectional 
Communications and Control 
______________________________________ 
The disclosures of the foregoing Echelon patents are incorporated herein by 
reference. Access to these publications as well as other information 
publicly available from Echelon Corporation should enable those of 
ordinary skill in the art to make and use a network system, following the 
description set forth herein for achieving desired functionalities. 
The local operating network is used to combine the various functional units 
of the dispenser in a distributed, rather than central, architecture. The 
system is made up of a plurality of microcontrollers which form network 
nodes. Each node is dedicated to a simple task. Communications between the 
various nodes are via message packets called network variables. The 
invention makes possible an open architecture, in which various functional 
units can be combined as desired to make a specific desired dispenser 
configuration merely by adding or deleting a dispenser element and its 
associated control node, and connecting the node to the communications 
bus. The communications bus provides power supply to the various nodes, as 
well as data and program updates, so that separate power supply wiring is 
not required. 
FIG. 2 shows a functional block diagram of the architecture for a 
multi-product dispenser, either with or without the card reader in 
dispenser (CRIND) functionality. As seen in FIG. 2, the communications bus 
102 has various nodes connected to it by the node connections described by 
Echelon in its product literature. Thus, a side A display node 120 is 
connected, having its associated price posting unit displays 14, the same 
as the price posting units of FIG. 1. Similarly, the side B display node 
122 has PPU displays 18. The bus 102 also has connected an A side card 
reader display 190 and a B side card reader display node 192, an A side 
card reader node 194 and a B side card reader node 196, an A side note 
acceptor node 198 and a B side note acceptor node 200, and an A side 
printer node 202 and a B side printer node 204. The CRIND display node 190 
may, if desired, be a video display or a single- or multi-line display. 
The communications bus 102 is a five-wire bus having two data wires, a 
reset wire and two power supply wires for the nodes. Other possibilities 
such as a two-wire bus that achieves power and communications objectives 
can be used. The power supply wires provide electrical power to the nodes 
for use by their associated functional components. Each microcontroller 
node includes a network communication port, a read-only memory storing a 
communications protocol, a memory-storing application code suitable for 
that node, and input/output pins and counter/timers. 
The communication bus 102 also has connected to it three separate 
pulser/hydraulic nodes 140,142,144. The number of these nodes can vary 
depending on the number of grades of fuel the dispenser is to be capable 
of dispensing. A vapor recovery node 206 and an auxiliary preset node 208 
can also be provided. 
The dispenser 100 also has either a two-wire keypad node 170 or a card 
reader control node 180, but both are not required. Both are shown in FIG. 
2 for the sake of making it clear that either can be provided. The fact 
that only one of the two is needed is indicated by surrounding each by a 
dotted line. If the two-wire keypad node 170 is used, it receives the 
signals from manager keypad 36 and any optional keypads 172. It 
communicates with a site controller over a two-wire connection 171. If the 
two-wire keypad 170 is used, then the nodes 190, 192, 194, 196, 
198,200,202,204 are less likely to be desirable and are likely omitted. 
If the card reader control node 180 is used, it receives the signals from 
the manager keypad 36 and any optional keypads 172, along with any keypads 
182,184 specifically provided for operating the card reader. These are 
supplied, for example, to permit a customer to select options of prices, 
other purchase choices, or the like. 
The functionality achieved in the dispenser of FIG. 2 can be achieved in 
various configurations of nodes. The minimum required for an effective 
fuel dispenser is at least one pulser hydraulic node such as node 140, at 
least one display 120 and one or the other of card reader control node 180 
or two-wire keypad node 170. The printer node 202 may, as is conventional, 
be used to print receipts for customers, and the like. 
Additional functionalities can be very easily added by retrofitting the 
dispenser to add the functioning component (e.g., a note acceptor) and 
adding associated microchip nodes to the communications bus 102. In 
addition, there may be some software changes to the pre-existing nodes to 
accommodate the added note acceptor. These can be communicated from the 
console controller over twisted pair 54 or the manager keypad 36 or a 
Maintenance/Diagnostic node temporarily installed for this purpose. 
Similarly, in making up a new dispenser, the assembly is much simpler 
since the local operating network communications bus 102 can be provided 
in a housing, with the necessary components added as needed in a 
configuration as required by a customer. 
Turning now to FIG. 3, details of the electronic components of a typical 
node 104 are shown. The communications bus 102 has connected to it the 
neuron chip 106. In some cases, it is desirable to have a ROM/RAM memory 
108 available to supply additional data or program for the chip 106. A 
clock 110 is provided to provide clock pulses to the chip 106. The chip 
106 also has an input/output interface 112 to the functioning components 
of dispenser associated with that node. In some cases, there is also an 
external CPU 116 connected by an optional microprocessor interface 
program, such as the MIP program sold by Echelon (hereinafter "MIP") 114 
to the neuron chip 106. The MIP software provides a high level user 
interface between the neuron 106 and the microprocessor 116. The 
microprocessor 116 may be a Z80, 68000, etc. The MIP's purpose is to allow 
the exchange of control information between the neurons and the external 
processor. 
The chip 106 is preferably an Echelon neuron chip, which comes in two 
versions--Model 3120 and 3150. Each of these chips is available from both 
Motorola, Inc. and Toshiba Electronics Corporation. The neuron chip has a 
1.25 megabits per second data rate, so that the serial signal on the 
two-wire data lines can be fast enough to take care of any needed data or 
command exchanges. 
The neuron 3120 chip has a network communication port, 10 kilobytes of 
preprogrammed ROM, which provides neuron firmware and communications, 512 
bytes of EEPROM for user application code, one kilobyte of RAM for node 
communications and applications data, eleven software configurable 
input/output pins, and two 16 bit counter timers. 
The neuron 3150 chip has a network communications port. It has no on-chip 
RAM, but it does have an external memory bus available to be attached to 
ROM and RAM, providing a total of 64 kilobytes of total memory. The chip 
itself has 42 kilobytes of user application code space, 2 kilobytes RAM 
for node communications and applications data, 11 software configurable 
I/O pins and two 16 bit counter/timers. 
The Echelon communications protocol is built into these neuron chips. It is 
a 7-layer protocol and uses network variables. The protocol includes 
message services as follows: acknowledged service, request/response, 
unacknowledged repeated, unacknowledged and authenticated message service. 
The Echelon software is a C-like language with extensions, including the 
network variable types. There are at least 5 input/output models supported 
in the software library published by Echelon. Message exchanges are 
accomplished using binding. The binder is software that initializes all 
the communications parameters of the neuron chip. Network variables are 
constructs that the Echelon language provides in a protocol to move data 
on the network. 
FIG. 4 is a more detailed functional block diagram of the components 
associated with the display node 124. The display node 124 includes the 
neuron chip 124 having a data link to a main display 126, which in turn is 
linked to the PPU displays 14. One display node per side is required 
according to a preferred embodiment. The neuron chip 124 can be 
incorporated on a main display board for the dispenser and is shown so 
consolidated in FIG. 2. The chip 124 drives the PPU board 14 and also 
performs transaction calculations to display the amount sold and the 
associated dollar value on the display 126. Each PPU could be a separate 
node in another embodiment. 
FIG. 5 shows the components of the pulser hydraulic node 140. These include 
neuron chip 146 associated with its peripheral functioning units. For a 
typical two-sided dispenser, there will be two pump handles 148, two 
quadrature pulsers 150, two pulser fail circuitry signal units 152, two 
main valves 154, two slow-down valves 156, and an STP motor 158 associated 
with each grade of fuel, assuming installation in a multi-product 
dispenser. Thus, one node is provided per each two pulsers. The chip 146 
receives signals from the pump handle 148 and output signals on 
communications bus 102 to indicate that the pump handle has been lifted. 
That signal is used by other nodes in the dispenser, as picked up from the 
communications bus 102 to indicate that the dispenser is turned on. The 
neuron chip 146 also turns on the STP motor 158 for the grade of fuel 
associated with the handle that has been lifted. Typically, the STP motor 
pressurizes the conduit, but liquid does not flow until a valve in the 
dispensing nozzle is open. That causes liquid to flow, which causes the 
generation of output pulses from the associated quadrature pulser 150 to 
the neuron chip 146. This series of pulses is converted to a volume of 
liquid dispensed using a preset conversion factor in the neuron chip 146. 
Alternatively, the pulser data could be transmitted to the communications 
bus 102 for conversion elsewhere, such as at the display node. 
Pulser fail circuitry 152, known to those of ordinary skill in the art, 
monitors operation of the quadrature pulser and will provide an error 
signal to the neuron chip 146, should an error be detected. A quadrature 
pulser produces two pulse trains that are 90.degree. out of phase. This 
provides direction of rotation information that can be sensed. 
Alternatively, more conventional pulsers which provide electronic pulse 
trains that are 180.degree. out of phase can be used, but direction of 
rotation cannot be ascertained from that type of pulser data. 
The neuron chip 146 also controls the main valve 154, causing that valve to 
open when the pump handle 148 is lifted. In some cases, a slowdown valve 
156 is employed in the dispenser. Slowdown valves 156 are known, in 
particular, for dispensers that pump a preset value of fuel, with the 
valve restricting the flow of liquid toward the end of that transaction to 
assure that the amount dispensed does not overshoot the dispensed fuel 
amount appropriate for the preset value. 
As noted, the preferred embodiment discloses the pulser hydraulic chip 146 
as controlling various functioning dispenser components. If desired, the 
local operating network could be configured to have separate nodes for 
each of those components. 
FIG. 6 shows the structure of the two-wire/keypad node 170. As noted above, 
the two-wire keypad node 170 is used in lieu of the card reader node 180 
when card reader capability is not required. The two-wire keypad 170 is 
connected to the communications bus 102 and includes a neuron processor 
106 similar to the 3150 chip described above. The neuron processor 
receives data from the manager keypad 36 and the optional keypad 172, 
which might be added to the system. The neuron processor 106 also is 
connected to a serial controller 118 such as a UART which, in turn, 
communicates over two-wire communication line 112 to a site controller. 
Only one of the two-wire keypad nodes 170 is required for each dispenser, 
since it is capable of performing needed roles for each side of the 
dispenser. 
The two-wire keypad node acts as a pump state enforcer, scans and 
interprets the manager keypad 36 and handles pump/console communications. 
As the pump state enforcer, it ensures that the proper control sequences 
for the pump dispenser have occurred to allow pump operation. That is, the 
pump state is a term used to indicate the condition that the pump is in, 
such as idle, pumping, etc. These states are arrived at by a certain 
control sequences, and the two-wire keypad node assures that the proper 
control sequence has occurred to allow pump operation. In scanning and 
interpreting the manager keypad, the two-wire keypad node electronically 
reads any data being supplied to the system over the keypad 36. This data 
might take the form of input data or, more commonly, perhaps assuming 
control of the operation of the dispenser or updating program options. 
The two-wire keypad 170 also provides through its serial controller a UART 
functionality for external serial communications. UART is an acronym for 
Universal Asynchronous Receiver Transmitter, which is a silicon chip that 
handles the transmission and reception of serial data. 
If desired, the dispenser can be made in a stand-alone version, in which 
case the two-wire keypad node 170 would not need to have the two-wire 
communication line 112 to the site controller. 
Turning now to FIG. 7, the structure of a CRIND control node 180 is 
described. The CRIND control node controls the card reader options and 
uses the Echelon neuron 3150 microprocessor 106. It also has associated an 
application server processor 116, which is a higher level microprocessor, 
such as those of the class of 68xxx, 80x86, or Z180. The application 
server processor also has a twisted pair connection 54 to the site 
controller. The communications over line 54 preferably use known Gilbarco 
protocols for transmitting and receiving credit card numbers, credit card 
authorization, and dollar amounts, and other information necessary for 
transmission between the dispenser and a site controller in accordance 
with conventional protocols. If desired, the apparatus disclosed in 
pending U.S. patent application Ser. No. 08/237,148, filed May 3, 1994 to 
Long et al., may be used as the line 54. The processor 106 is connected to 
keypads 182, 184 servicing dispenser side A and dispenser side B 
respectively. From the keypads, customers may indicate selections to the 
dispenser, such as what type of credit card to pay with, whether credit or 
cash or debit transaction is required, or if any other selection, such as, 
for example, the selections for car wash purchases described in U.S. 
patent application Ser. No. 08/271,553 now U.S. Pat. No. 5,493,315 filed 
Jul. 7, 1994, of Atchley, the entire disclosure of which is incorporated 
herein by reference. Also the card reader technologies described in the 
patents identified above in connection with the discussion of FIG. 1 may 
be used. 
The neuron processor 106 receives data from the manager keypad 36 and any 
other additional optional keypads 172, which may be provided. The 
processor 106 receives and provides data onto the bus 102 and receives and 
provides data to the application server processor 116 according to 
software embedded in each. 
As an example of the way the Echelon hardware and software are interfaced 
with a fuel dispenser, more details of the operation of the CRIND control 
node 180 is seen, in connection with the following description of FIGS. 
8-12. The application processor 116 has three areas 220, 222, 224, 
speaking figuratively, for operation of the CRIND control node 180. Area 
220 provides application control for side A of the dispenser. 
Area 222 of the application processor 116 provides application processor 
control for the side B of the dispenser. Area 224 provides BIOS for the 
two areas 220,222 as well as connection to the twisted pair 54 and 
connection to the neuron chip 106. Chip 106 which provides message 
interpretation and transmission to and from the application processor 116 
from the communications bus 102. 
A typical sequence of operations and communications is shown by the arrows 
and encircled numbers in FIG. 8. Thus, a first step might be a service 
request by area 220 for side A communicated to the BIOS area 224. The BIOS 
area 224 responds with an acknowledgement 2. Further, the BIOS 224 outputs 
a network variable output request 3 to the chip 106 which, in turn, 
provides a network variable input event 4. This is followed by a side B 
application service request 5 and a side B application BIOS event 6. Thus, 
the BIOS area 224 serves as a "traffic cop" for the sides A and B 
applications 220, 224 communicating with the communications bus 102 
through the neuron chip 106 and also with the site controller over the 
twisted pair 54. 
Referring now to FIGS. 9-11, a more concrete example of how these 
components work together will be described with reference to an A side 
card reader node 194 including a card reader 195 connected to a neuron 
processor 106. A customer inputs a card 197 into the card reader 195 at 
step A. At step B, the neuron processor senses card insertion and updates 
its "A side card inserted" network variable. The network variable update 
automatically causes the network variable message to be placed on the 
communications bus 102. The updated network variable is transmitted over 
the communications bus 102 and noticed by the neuron processor 106 of the 
CRIND control node 180 (see FIG. 10). Thus, the "A side card inserted" 
network variable update is received by the neuron processor 106 of the 
CRIND control node 180. That neuron processor 106 returns an 
acknowledgement message to the card reader node 194 over bus 102 and sends 
card reader event information into the BIOS 224. As seen in FIG. 11, the 
BIOS area 224 converts the event information into proper format and flag 
for the side A application processor 220, which can provide its own output 
according to the programming set forth in the side A application 
processor. 
The various types of communications which can take place between the 
various nodes is set forth in the dataflow diagram attached as FIG. 13. 
The messages available along the numbered lines of the dataflow diagram 
are as follows: 
__________________________________________________________________________ 
Number 
From To Signal Name 
__________________________________________________________________________ 
1 Control Printer Printer Data 
.cndot. Transaction Data 
.cndot. Diagnostics Data 
2 Printer Control Paper Status 
.cndot. Paper Low 
.cndot. Out of Paper 
.cndot. Paper Okay 
Printer Status 
.cndot. Idle/Busy 
.cndot. Jammed 
.cndot. Top Sensor 
.cndot. Loop Back 
.cndot. Busy Stuck 
Door Status 
.cndot. Open 
.cndot. Closed 
3 Control CRIND Display 
Display Data 
.cndot. Prompts 
.cndot. Error Codes 
.cndot. Advertisements 
.cndot. Special Messages 
4 CRIND Display 
Control Display Status 
.cndot. Idle 
.cndot. Memory Full 
5 Card Reader 
Control Card Reader Data 
.cndot. Track 1 Data 
.cndot. Track 2 Data 
.cndot. Security Track Data 
Card Status 
.cndot. Card In 
.cndot. Card Out 
.cndot. Valid/Invalid 
6 Control Card Reader 
Control 
(Motorized) 
.cndot. Reject 
.cndot. Eject 
.cndot. Eat 
.cndot. Hold 
.cndot. Release 
Data 
.cndot. Write to Track 1 
.cndot. Write to Track 2 
.cndot. Write to Smart Card 
7 Cash Acceptor 
Control Status 
.cndot. LRC In/Out A 
.cndot. LRC In/Out B 
.cndot. Bill In 
.cndot. Escrow 
.cndot. Stacked 
.cndot. Rejected Bill 
.cndot. Cheat Status 
.cndot. Idle 
8 Control Cash Aceeptor 
Control 
.cndot. Stack 
.cndot. Reject 
.cndot. Configure 
9 Control Transaction 
.cndot. PPU Data 
Display .cndot. Preset Data 
.cndot. Volume Allocation 
.cndot. Cash Allocation 
.cndot. Manager Keypad Data 
.cndot. Error Messages 
10 Pulser/Hydraulic 
Transaction 
.cndot. Volume Dispensed Data 
Display 
11 Transaction 
Control .cndot. Transaction Data 
Display Uncompensated 
.cndot. Transaction Data 
Compensated 
.cndot. Display Error Checking 
12 Transaction 
Pulser Hydraulic 
.cndot. Preset Volume Goal 
Display .cndot. Grad Information 
(Blender, SHMPD) 
13 Control Pulser Hydraulic 
Conversion Factor 
.cndot. U.S. Gallons 
.cndot. U.S. Gallons to Imperial 
Gallons 
.cndot. 1012 Pulses Per Gallon 
Grade Assignment 
14 Pulser/Hydraulic 
.cndot. Transaction 
Status 
Display .cndot. Pump Handles 
.cndot. Pulsers 
.cndot. Valves 
.cndot. STP/Motor 
.cndot. Preset Goal 
15 All Nodes 
All Nodes 
.cndot. Deauthorization 
16 Control All Nodes 
.cndot. Authorization 
20 ATC Pulser/Hydraulic 
.cndot. Temperature Data 
VVac .cndot. Volume Correction 
Factor (VCF) 
21 Control ATC Configuration 
.cndot. Fuel Types 
.cndot. Fuel Density 
22 ATC Transaction 
ATC Data 
(Pulser/Hydraulic 
Display .cndot. Temp 
.cndot. Diagnostics 
.cndot. Compensated Volume 
.cndot. Uncompensated Volume 
.cndot. Fuel Type 
.cndot. Fuel Density 
.cndot. VCF 
23 Control All .cndot. Diagnostics Command 
.cndot. Power Fail 
24 All Control .cndot. Diagnostics Status 
25 Option Control Option Switch Data 
.cndot. Pump Preset 
.cndot. Cash/Credit 
.cndot. Grade Select 
.cndot. CRIND Keypad 
__________________________________________________________________________ 
The local operating network open architecture made available by the 
invention provides for very versatile design capabilities in designing 
further dispensers. For example, although the dispenser architecture shown 
in FIG. 2 shows several pulser/hydraulic nodes, the number of 
pulser/hydraulic nodes can be quite variable, as desired. That is, 
multiple grades can be easily added by simply adding additional nodes to 
the communications bus 102 and its associated hardware. Thus, for a 
three-grade multi-product dispenser, six nodes are used, three 
pulsers/hydraulic nodes, two display nodes, and one two-wire keypad node 
(or CRIND control node). 
The card reader capability made available by the card reader control node 
180 makes available multiple options, as suggested above in connection 
with FIG. 2, including the possibility of providing one or more card 
readers, note acceptors and printers on each side of the dispenser. 
Furthermore, should additional functionality in the form of displays to 
the customer be desired, those can be added simply. For example, the 
displays can be full screen displays as disclosed in U.S. patent 
application Ser. No. 07/960,512, filed Oct. 13, 1992; now abandoned and 
continued as Ser. No. 08/539,505 filed Oct. 6, 1995 U.S. patent 
application Ser. No. 07/959,844, filed Oct. 13, 1992; now abandoned, 
continued as application Ser. No. 08/271,553 now U.S. Pat. No. 5,493,315 
and U.S. patent application Ser. No. 07/960,515, filed Oct. 13, 1992 now 
U.S. Pat. No. 5,543,849. The disclosures of these applications are hereby 
incorporated by reference. This added flexibility makes it possible to 
upgrade and retrofit already-installed dispensers with only relatively 
easy-to-perform modifications and substitutions as required. 
The invention can also be incorporated in a blending-type dispenser 240 
shown in FIG. 12. Here a pulser hydraulic node 242 has associated pump 
handles 148, pulser fail logic circuitry 152, quadrature pulsers 150, main 
valves 154, slow-flow valves 156 and submerged turbine pumps 158. The 
design of the blending hardware may be as described in the U.S. patents 
mentioned above in connection with the description of FIG. 1. Data from 
the pulser hydraulic node 242 is put onto the communications bus 102 and 
thereby communicates with the displays 120,122 as well as two-wire keypad 
node 170 as described above. 
The local operating network may also be used to operate a vapor recovery 
fuel dispenser, as suggested above in connection with item 206 of FIG. 2. 
The vapor recovery technology is preferably an assist-type vapor recovery 
as taught in U.S. Pat. No. 5,040,577 to Pope and one or more of U.S. Pat. 
Nos. 5,269,353 to Nanaji et al.; 5,156,199 to Hartsell et al.; 5,355,915 
to Payne; 5,435,979 to Tucker et al. or U.S. patent application Ser. Nos. 
08/131,313 filed Oct. 4, 1993 to Hartsell et al. now U.S. Pat. No. 
5,417,256; 08/033,311 filed Mar. 15, 1993 to Hartsell, Jr. et al.; now 
U.S. Pat. No. 5,450,883; 08/192,669 filed Feb. 7, 1994 to Hartsell et al.; 
08/294,108 filed Aug. 22, 1994 to Payne et al. now U.S. Pat. No. 
5,542,458; 08/153,528 filed Nov. 16, 1993 to Nanaji et al.; now U.S. Pat. 
No. 5,464,466 and 08/274,302 filed Jul. 11, 1994 to Hartsell et al. now 
abandoned, the disclosures of which are incorporated herein by reference. 
Alternatively, the vapor recovery node may interface with other vapor 
recovery technologies such as WayneVac sold by Wayne Division of Dresser 
Industries, MaxVac sold by Tokheim or other assist-type systems. 
The local operating network concept may also be incorporated in a 
temperature compensation fuel dispenser, in which data concerning the 
temperature of the fuel is used to correct for thermal expansion or 
contraction of the fuel and thereby correct at displays the value and 
amounts being sold, in accordance with U.S. patent application Ser. No. 
08/279,174, filed Jul. 22, 1994, of Von Cannon, the entire disclosure of 
which is incorporated herein by reference. 
The invention provides numerous benefits. There are reductions in materials 
costs in that the distributed architecture lends itself to distributed 
power regulation. This requires, therefore, fewer cables and connectors 
for the electronics assembly. 
There are reduced manufacturing costs using the present invention. There 
are fewer cables to connect, resulting in faster assembly with fewer 
misconnections. The design according to the present invention eliminates 
the configuration jumpjacks which have previously been used on display 
boards. The nodes can also be programmed to have the ability to self-test 
each other for defects. 
The software used with the present invention is of decreased complexity 
since it is distributed into functional modules instead of being 
concentrated in a central high level processor. This results in virtually 
a "one-program" pump. 
The invention provides scalability from low end to high end models of 
dispensers, with no unutilized components being packaged in any assembly. 
The plurality of processors in the local operating network design can 
provide service technicians with increased resident diagnostic functions, 
therefore making it easier to service units in the field and quickening 
the mean time to repair. 
The design also provides increased packaging flexibility of the components 
in a dispenser. The nodes can be placed on or next to the devices which 
they control. 
The invention also permits easy add-ons, including the possibility of 
automatic reconfigurations as options are added. The invention also 
provides the ability to add future options easily, including options not 
contemplated at the time of original manufacture. 
Also, the modular aspect of the local operating network permits the design 
to be refined for different needs, including the needs of different 
standards in different countries. 
Accordingly, it should be appreciated that the invention provides very 
broad flexibility in designing fuel dispensers taking advantage of local 
operating network capability. Those of ordinary skill in the art will 
appreciate that the invention can take different forms than those 
specifically described hereinabove, and the spirit and scope of the claims 
of this application, not the specific disclosure, will provide the measure 
of protection afforded.