Abstract:
A fuel transfer pump electrical circuit for controlling a fuel transfer pump comprises a controller with communications logic configured for establishing a wireless communications link with a mobile device and a switch for activating a motor in the pump. The switch is controllably linked to the controller. The controller is configured to turn the switch on and off based on instructions received via the wireless communications link, thereby controlling the fuel transfer pump to turn a flow of fuel on and off. A mobile device application for interacting with the fuel transfer pump is also described.

Description:
BACKGROUND 
       [0001]    Tracking the use of equipment in the field continues to pose challenges. Equipment owners need to permit access of equipment so that it is fully utilized, which increases benefits to end users and owners alike. At the same time, owners must control access to equipment to ensure only authorized users have access to prevent theft, tampering and other unauthorized activities, as well as to ensure safety of the surroundings. Further, equipment owners struggle with ensuring that even authorized users use the equipment correctly so that they enjoy a positive experience and the equipment&#39;s useful life and intervals between required service are maximized. Moreover, owners desire to have more tracking information regarding users&#39; interactions with equipment. For example, in the case of fuel transfer pumps used to transfer fuel for vehicles, which are often located in remote areas, pump operators seek to have more control. Pump operators desire to permit authorized users to access transfer pumps at any time of day and without cumbersome procedures, yet maintain accurate records of each user interaction with a pump for purposes of security and accurate accounting, but conventional solutions are lacking. 
       SUMMARY 
       [0002]    Described below are implementations of a fuel transfer pump electrical circuit for controlling a fuel transfer pump that address the drawbacks of conventional approaches. 
         [0003]    According to a first implementation, a fuel transfer pump electrical circuit for controlling a fuel transfer pump, comprises a controller and a switch. The controller has communications logic configured for establishing a wireless communications link with a mobile device. The switch is for activating a motor in the pump, and is controllably linked to the controller. The controller is configured to turn the switch on and off based on instructions received via the wireless communications link. 
         [0004]    In one implementation, the fuel transfer pump electrical circuit may further comprise a flow meter control logic connectible to a flow meter associated with the fuel transfer pump. The flow meter control logic comprises communications logic configured for establishing a separate flow meter wireless communications link with the mobile device via which flow data from the flow meter can be transmitted to mobile device. 
         [0005]    In one implementation, the fuel transfer pump electrical circuit may further comprise a flow meter electrical circuit connected to a flow meter for the fuel transfer pump. The flow meter electrical circuit may comprise a flow meter controller with communications logic configured for establishing a flow meter wireless communications link with the mobile device and a flow meter switch controllably linked to the flow meter controller and connectable to the flow meter. 
         [0006]    In one implementation, the controller is configured to receive an output set characteristic communicated from the mobile device via the wireless communications link and in response to control the switch to turn the fuel transfer pump on and off. 
         [0007]    In one implementation, the flow meter controller comprises a pulser input configured to receive pulse counts indicating operation of the flow meter and to transmit the pulse counts to the mobile device via the flow meter wireless communications link. 
         [0008]    In another implementation, a control circuit for a fuel transfer pump and associated flow meter comprises a circuit board configured for installation in a recess of a housing. The circuit board comprises a fuel transfer pump controller with communications logic configured for establishing a wireless communications link with a mobile device and a fuel transfer pump switch for activating a motor in the pump, the switch being controllably linked to the fuel transfer pump controller, and a pulser input linked to the controller and configured to receive pulse counts indicating operation of a flow meter associated with the fuel transfer pump. 
         [0009]    In one implementation, the fuel transfer pump comprises the housing for the circuit board. In another implementation, the housing comprises a separate housing configured to be coupled to the fuel transfer pump. In another implementation, the housing is an explosion proof housing. 
         [0010]    In one implementation, the circuit comprises at least one of an accelerometer and an altimeter. In one implementation, the wireless communications link are established according to a Bluetooth low energy protocol. 
         [0011]    In one implementation, the circuit board comprises a memory for storing fuel transfer pump operation data, and wherein the fuel transfer pump controller causes fuel transfer pump data for a most recent transaction to be uploaded to the mobile device for communication to a web service upon restoration of the wireless communications link following an interruption. 
         [0012]    In one implementation, the circuit board comprises a memory for storing fuel transfer pump operation data, and wherein the fuel transfer pump controller causes fuel transfer pump data for at least one prior incomplete transaction to be uploaded to the mobile device for communication to a web service upon establishment of a new wireless communications link following the incomplete transaction. 
         [0013]    According to another implementation, a software application for configuring a mobile device to control a fuel transfer pump system comprises instructions for establishing a wireless communications link between the mobile device and a circuit of the fuel transfer pump, instructions for establishing a wireless communications link between the mobile device and a web service and instructions for carrying out two-factor authentication of the mobile device through queries displayed to the user on the mobile device and communications of data to the web service to determine if the mobile device is authorized. If the mobile device is authorized, instructions for displaying fuel transfer pump operation commands on the mobile device, receiving user input via the mobile device corresponding to a selected command and communicating the command to the fuel transfer pump circuit are carried out. 
         [0014]    In one implementation, the software application comprises instructions to cause transaction data from the fuel transfer pump to be communicated from the fuel transfer pump to the mobile device and from the mobile device to the web service. In one implementation, the instructions to cause data from the fuel transfer pump to be communicated to the mobile device are issued following completion of a fuel transfer pump pumping event. In one implementation, the instructions to cause data from the fuel transfer pump to be communicated to the mobile device are issued following resumption of a wireless communication link between the mobile device and the fuel transfer pump following an interruption. 
         [0015]    In one implementation, the instructions to cause data from the fuel transfer pump to be communicated to the mobile device are issued following establishment of a new wireless communication link between a new mobile device and the fuel transfer pump following an incomplete transaction, and the data communicated comprises data for at least one prior incomplete transaction. 
         [0016]    In one implementation, the software application comprises instructions for transmitting flow meter data received from the fuel transfer pump system to the web service. In one implementation, the software application comprises instructions for transmitting flow transfer pump data from the fuel transfer pump system to the web service. 
         [0017]    In one implementation, the software application comprises instructions for querying a user for a selected location, receiving an input from the mobile device indicating a selected location and displaying fuel transfer pump locations corresponding to the selected location. 
         [0018]    In one implementation, the software application comprises instructions for querying a user for a selected asset to be fueled, receiving an input from the mobile device indicating a selected asset and displaying asset information for the selected asset to the user. 
         [0019]    The foregoing and other features and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a schematic block diagram of a fuel transfer pump system providing for remote control via a mobile device. 
           [0021]      FIG. 2  is a representative drawing showing a fuel transfer pump and an associated fuel meter coupled to the fuel transfer pump. 
           [0022]      FIGS. 3A, 3B and 3C  are flow diagrams of a process for authorizing a mobile device user and carrying out fuel transfer pump operations. 
           [0023]      FIG. 4  is a schematic network diagram showing the fuel transfer pump system connected to the mobile device, which is in turn connected to a web services host to enable synchronous web services. 
           [0024]      FIG. 5  is a schematic block diagram of a fuel transfer pump system according to another implementation. 
           [0025]      FIG. 6  is a drawing of a separate housing used in some implementations to house all or a part of a circuit. 
           [0026]      FIGS. 7A and 7B  are drawings of components of a separate housing according to another implementation. 
           [0027]      FIGS. 8A and 8B  are drawings showing the other sides of the components of the separate housing of  FIGS. 7A and 7B . 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    Described below are implementations of a circuit providing for remote control of equipment, e.g., a fuel transfer pump or other similar equipment, using a mobile device. 
         [0029]    Referring to  FIGS. 1 and 2 , a fuel transfer pump system  100  includes a fuel transfer pump  110 , a fuel meter  120  and a mobile device  200  ( FIG. 1 ). The fuel transfer pump  100  can be a conventional fuel transfer pump suitable for transferring fuel (e.g., gasoline, diesel and other similar liquids), such as between a container and a vehicle. Such fuel transfer pumps can be installed at fixed locations, mounted to vehicles (such as to vehicle-mounted fuel supply tanks) or implemented as portable pumps. One suitable conventional fuel transfer pump is the Fill-Rite® 20 GPM (gallon per minute) high flow model, but fuel transfer pumps having higher or lower flow rates can also be used. In the illustrated implementation, the fuel transfer pump  110  is configured to be powered by DC power, such as 12-volt DC power, but pumps using other sources of power, including 24-volt DC and AC power, can also be used. 
         [0030]    Referring to  FIG. 2 , the fuel transfer pump  110  has a body  112  with a pump inlet  113  and a pump outlet  116 . The body  112  houses a motor and various other components of the pump (not shown). In the illustrated implementation, the fuel meter  120  is connected to the pump outlet  116  to receive a flow of fuel exiting the fuel transfer pump  110  and to measure its flow rate and/or volume. The fuel meter  120  is typically a conventional, high-accuracy mechanical flow meter with a body  124  that houses its internal components. Typically, a flexible hose with a lever-operated nozzle (not shown) is attached to a flow meter outlet  122 . In use, provided the fuel transfer pump is in its operating mode as discussed below, the user activates the nozzle by squeezing a lever to cause fuel to flow into the tank and/or connector into which the nozzle is inserted. The nozzle may have a conventional hold-open lever or other similar device allowing the user to keep it in the activated position without requiring the user to continuously squeeze it. 
         [0031]    As shown in  FIG. 2 , the fuel meter  120  has been fitted with a customized fuel meter circuit  126 , which is housed in a recess of the body  124 . Similarly, the fuel transfer pump  110  has been fitted with a customized fuel transfer pump circuit  114  housed in a recess of the body  112 . (In another embodiment which is described below in detail, at least a part of a fuel transfer pump circuit is housed in a separate housing, which is typically attached to the fuel transfer pump&#39;s electrical input connection.) The fuel meter circuit  126  and the fuel transfer pump circuit  114  are explained in further detail with reference to the block diagram of  FIG. 1 . In the illustrated implementation, the fuel meter circuit  126  and the fuel transfer pump circuit are configured as circuit boards, but other topologies could of course be used. 
         [0032]      FIG. 1  shows the fuel transfer pump circuit  114  and the fuel meter circuit  126  linked to a mobile device  200 , such as a smart phone, a tablet computer, a laptop computer, a dedicated remote controller or another type of mobile device. As indicated, the mobile device  200  is linked to each of the fuel meter circuit  126  and the fuel transfer circuit  114  by a wireless connection. In one implementation, the wireless connections are Bluetooth connections. In some implementations, connections are established using the Bluetooth LE (low energy) standard, which, among other advantages, conserves battery power. Other Bluetooth standards, such as Bluetooth 5.0, can also be implemented. In addition to Bluetooth, it is of course possible to use other suitable wireless technologies to configure links between the mobile device  200  and the fuel meter circuit  126  and the fuel transfer pump circuit  114 . 
         [0033]    A variety of communications configurations can be configured between the fuel transfer pump circuit, the fuel meter circuit and the mobile device. For example, in one alternative implementation described in detail below, the mobile device  200  communicates directly with the fuel transfer circuit  114 , which in turn communicates with the fuel meter circuit  126  using a second communications link, which could be a wireless or wired connection. 
         [0034]    The fuel transfer pump circuit  114  comprises a controller  130 A, which is connected to the motor of the fuel pump  110  via a switch or a transistor  132 A, such as a 25-amp MOSFET transistor. The controller  130 A receives power, such as 6-30 DC power, from a battery  134  (see also  FIG. 2 ), which is converted to 5V DC at 800 mA (see block  136 ). Optionally, there can be a battery backup  138 A to supply DC power, such as 3.7V at 250 mA. The controller  130 A has a connection to a serial interface  140 A. The serial interface  140 A can provide for connecting a programming harness to the circuit to update or change functionality of its components, including the controller. 
         [0035]    In the illustrated implementation, the controller is linked to a memory, one or more sensors and a clock. Specifically, the controller is  130 A is linked to a memory  142 A, such as a 64 kB EEPROM, two types of sensors (including an accelerometer  144 A and an altimeter  146 A) and a real-time clock  148 A. The controller  130  can also be linked to an optional LED  150 A, which can be configured to indicate a visual alert and/or operational status. The controller  130 A can be configured to receive pulser input  152 A, although such input is not used in the illustrated implementation of the fuel transfer pump circuit  114 . 
         [0036]    Although not required, in the illustrated implementation, the fuel meter circuit  126  is substantially identical to the fuel transfer pump circuit  114 . Thus, the same components are referred to with like reference numerals, appended with the suffix B. In the illustrated implementation, the fuel meter circuit board  126  has a pulser input  152 B from the fuel meter that is fed to the controller  130 B. 
         [0037]    As illustrated, the fuel transfer pump circuit  114  can include an optional accelerometer  144 A and an optional altimeter  146 A, and the fuel meter circuit  126  can likewise include an optional accelerometer  144 B and altimeter  146 B. In some implementations, the controller is programmed to receive signals from the accelerometer and/or altimeter, such as, e.g., to detect motion of an associated component or object. Such signals can be processed to determine if they meet predetermined criteria, and, if so, a determination can be made, e.g., that the component or object is in operation or is in motion. For example, if input from the accelerometer  144 A meets a predetermined threshold, it can be determined that the fuel transfer pump is in operation. As another example, if input from the accelerometer  144 B or the altimeter  146 B has certain characteristics, it can be determined that tampering or theft may be occurring, and the system can be programmed to respond accordingly. 
         [0038]    In the illustrated implementation, each of the fuel transfer pump circuit  114  and the fuel meter circuit  126  is configured in a small form factor, such as a small circuit board or other type of circuit component, such that it can directly replace the corresponding OEM circuit element within the same recess. The circuits  114 ,  126  can be designed to have substantial current switching capabilities, such as up to 30 amps. In one specific implementation, embodiments of the fuel transfer circuit  114  operate with a pump motor current of up to about 25 amps. 
         [0039]    In the illustrated implementation, the controller  130 A,  130 B can be a single-chip micro energy radio with an integrated microprocessor. In the illustrated implementation, the connections between the memory  142 A,  142 B, the accelerometer  144 A,  144 B, the altimeter  146 A,  146 B and the clock  148 A,  148 B, to the controller  130 A,  130 B, respectively, can be optionally implemented using the I 2 C standard. Each controller (and/or one of its components) may comprise suitable circuitry, interfaces, logic and/or code, and can be used to coordinate activities and data flow. 
         [0040]      FIG. 5  is a schematic block diagram of a fuel transfer pump system similar to  FIG. 1 , but according to an alternative implementation in which control circuit functions are implemented using a single controller, such as in a fuel transfer pump circuit  414  as shown. Thus, the fuel meter circuit  126  and its separate controller  130 B are not required. In  FIG. 5 , elements of the fuel transfer circuit  414  having the same function as in the circuit fuel transfer  114  are labelled with the same reference numeral plus 300 and are not further described except as follows. 
         [0041]    As shown in  FIG. 5 , in the circuit  414 , the fuel meter  120  is electrically connected to the same switch or a transistor  432  to which the fuel transfer pump  110  is connected. In this way, the fuel meter  120  is activated at the same time as the fuel transfer pump  110 . The electrical connection between the switch or transistor  432  and the fuel meter  120  can be made with a short cable such that power is supplied to the fuel meter  120  as needed. The block  452  represents the pulser input  452 , which in this case is connected to the fuel meter  120  as shown to receive a signal from the fuel meter corresponding to the fuel meter&#39;s activity. 
         [0042]    In some implementations, one or more portions of the circuits are positioned in a separate housing(s). For example, as shown in  FIG. 6 , there is a separate housing  580  (shown with its cover removed to reveal a recess  582  defined within a body  584 ), and a fuel transfer circuit  514  is implemented on a circuit board  578  that is positioned within the recess  582 . In the illustrated implementation, the housing has three openings along its periphery: one for a power connection that supplies power to the fuel transfer circuit  514  (circuit board  578 ), one for the input to the pulser of the circuit from the fuel meter, and one that is threaded into the fuel transfer pump  110  and is connected to the electrical input connection. 
         [0043]      FIG. 7A  is an elevation view of a housing  680  according to another implementation. In the housing  680 , there is a recess  682  defined within a body  684 , and a fuel transfer circuit  614  is implemented on a circuit board  678  that is positioned within the recess  682 . A cover  686  shaped to cover the housing  680  is shown in  FIG. 7B . The cover  686  can have an opening  688  through which conductors can be routed to and from the circuit board  678 . 
         [0044]      FIG. 8A  is an elevation view of the housing  680  viewed from an opposite side. The cover  680  can have a threaded nipple  690  via which the housing can be connected to the fuel transfer pump  110 .  FIG. 8B  is a drawing of the cover  686  viewed from an opposite side. As shown, the cover  686  can have an opening and a connection  690  for a power whip (i.e., cable) that connects to the pump electrical input and is stored in the pump cavity. 
         [0045]      FIGS. 3A, 3B and 3C  are flow diagrams illustrating operation of a software application on the mobile device  200 , which is referred to as a view controller (VC), while it is running and being used to interact with the fuel transfer pump system  100 . Following initialization of the VC by a user, in step  300  the VC prompts the user for authorization. The VC receives the user&#39;s response, which can be an entry via a touchscreen (or a voice command, a fingerprint scan or other similar type of user entry readily made with a mobile device) and/or a unique code or identification stored in the mobile device. 
         [0046]    Two-factor authentication can be used, such as by authorizing a registered user according to the user&#39;s phone number, assigned authorization code and mobile device UUID. Following the user&#39;s communication with a synchronous web service (WS), e.g., as shown in  FIG. 4 , the WS determines whether the user&#39;s phone number is in a database and, if so, issues an authorization token. The WS updates the database and causes a text message to be sent to the mobile device with a deep link to the authorization token (step  302 ). One suitable deep link technology is the Apple iOS Universal Links deep link technique, but other standards can also be used. After the user responds via the mobile device, then the token, the phone number and the mobile device UUID are retransmitted to the WS for authentication against the updated database values (step  304 ). If the user is authorized, then the process proceeds to step  306 . If the user is not determined to be authorized, then the process returns to step  300 . 
         [0047]    In the illustrated implementation, step  306  includes a subroutine that checks the last transaction completed by the mobile device and updates transaction records as necessary. Specifically, as shown in  FIG. 3B , in step  308  the memory of the mobile device is read, such as by a synchronous web service (WS) with which the VC is wirelessly connected, or other similar link, to determine a most recent transaction. In step  310 , it is determined whether the most recent transaction has already been processed, i.e., that a record of the transaction is in the system database. If so, then the process proceeds to step  320 . If not, then in step  322  the VC writes the transaction to the system database. In step  324 , the status of the most recent transaction in the mobile device memory is changed to “processed” to reflect that system database includes a record of the transaction. 
         [0048]    In some implementations, there is a second step  306 ′, which can be carried out instead of or in addition to the step  306 . Step  306 ′ includes a subroutine that checks if at least one previous transaction at the transfer pump is an incomplete transaction (i.e., one that was not successfully uploaded to the WS), without regard to whether the incomplete transaction(s) was by the same user/mobile device or by a different user(s)/different mobile device(s). This is another example of “condition handling” that can be enabled. In step  308 ′, the memory of the transfer pump circuit is read. In step  310 ′, it is determined whether there are any incomplete transactions that were not processed. If not, then the process proceeds to step  320 . If there is at least one incomplete transaction, then in step  322 ′, the VC receives the incomplete transaction data and uploads it to the system database. This is preferably done without disclosing the data to the current user or storing it on his mobile device, since the incomplete transaction may relate to another user/another mobile device. In step  324 , the status of the most recent transaction in the transfer pump circuit memory is changed to “processed” to reflect that system database includes a record of the transaction. 
         [0049]    Returning to the main process, in step  320 , the VC queries the user to enter his location. The user can enter his location, e.g., by way of reference to a geographic location, such as a particular pump location, or by coordinates, or by reference to a default location saved for the user, as just several examples. Alternatively, the current location of the mobile device can be determined automatically. During initialization of the application, the user can be prompted to allow location services to be used in connection with the application. If allowed, the application uses the mobile device&#39;s location services capabilities when triggered to determine a current location for use by the application. 
         [0050]    In step  322 , for the sake of explanation, it is assumed that the desired pump will be identified by the user, so the WS causes a listing of pumps to be displayed on the mobile device, such as, e.g., in order of proximity from the user&#39;s current location or another desired ordering. In step  324 , the user&#39;s input to select one of the pumps is evaluated to determine if it is valid. If not, the process flow returns to step  320 . 
         [0051]    In step  326 , the VC receives the user&#39;s selection of one of the pumps. In step  328 , the VC displays the stored information for the selected pump. Such information can include Equipment Number, Category, Class, Make, Model, maximum amount of fuel that can be pumped, etc. In step  328 , the VC then prompts the user to identify the asset, which may be a vehicle, equipment or another type of asset to which fuel is to be added. 
         [0052]    In step  330 , the WS returns stored information on the identified asset, including the type(s) of fuel suitable for the asset and its fuel capacity. In step  332 , the WS validates the entered asset identification. 
         [0053]    In step  334 , the VC receives communication(s) that the selected pump and corresponding meter are wirelessly linked or connected to the mobile device. In the illustrated implementation, the pump and the corresponding meter each establish a separate communication with the VC. For example, the VC can receive a SWITCH UUID from the fuel transfer pump circuit  114 , and a METER UUID from the fuel meter circuit  126 . In the illustrated implementation, the fuel transfer pump circuit  114  is configured to broadcast a Bluetooth BLE advertising packet of data that includes the SSWITCH UUID (or other identifier corresponding to the pump). Similarly, the fuel meter circuit is configured to broadcast a Bluetooth BLE advertising packet of data that includes the METER UUID (or other identifier corresponding to the meter). In step  336 , the VC determines whether the expected number of devices have been wirelessly connected. If not, then the process returns to step  334 . 
         [0054]    If the pump and the corresponding meter are successfully connected, then in step  338  the VC displays a “Pump Ready” or similar message. In step  340 , the VC determines whether the user has turned the pump on, such as via a PUMP ON/OFF button displayed on the VC. If the user has turned the pump on and depressed the lever on the nozzle, then the VC will display a real-time gauge showing the amount of fuel that has been pumped. The user can turn the pump off by pressing the PUMP ON/OFF button again. If the VC determines that the transaction is complete in step  342 , such as if the user has pressed a displayed COMPLETE TRANACTION button on the WC, then the process proceeds to step  344 , and the transaction data is stored in the memory of the mobile device. The VC is then reset to display the list of fuel pumps, and a button is displayed that the user can press to log off the application. 
         [0055]    In addition, the WS also stores the transaction data. For example, the transaction data may include the user information, location information, pump information, fuel type, asset identification amount of fuel, date, time and a system generated transaction identifier. If the upload of the transaction data from the VC to the WS is successful, then a message (e.g., “OK”) is displayed to the user. If the upload of the transaction data is not successful, then the system will attempt to upload it in step  306  as described above. In one implementation, any communication errors are logged on the server side. 
         [0056]    In one implementation in which Bluetooth LE communications are used, an output set characteristic is used to control the fuel transfer pump  110 . The instruction Output Set=1 will be sent to enable the pump, and the instruction Output Set=0 will be sent to disable it. For the fuel meter  120 , both the output set characteristic and a FC Ticks characteristic are used. The instruction Output Set=1 will enable the pulser, and the VC will be subscribed to the FC Ticks characteristic so that whenever a predetermined number of pulses is read (from one to several pulses over a selected interval), the number of read pulses is sent to the VC so that it can be displayed on the mobile device. In addition, pump operation data that includes the current draw on the pump motor can be tracked and stored (such data can be used for several purposes, including troubleshooting and scheduling maintenance). 
         [0057]    In the event that the communication link between the mobile device  200  and fuel transfer pump circuit  114  is interrupted, all outputs from the fuel transfer pump circuit  114  will be turned off. The controller  130 A will send an instruction to cause operation of the fuel transfer pump  110  to cease immediately, the switch  132 A will return to an open state, and the flow of fuel will be stopped. Similarly, in the event that the communication link between the mobile device  200  and the fuel meter circuit  126  is interrupted, all outputs from the fuel meter circuit  126  will be turned off. The pulser input  150 B indicating operation of the flow meter  120  will be turned off and no longer read. The controller  130 B will send an instruction to cause operation of the fuel meter  120  to cease immediately, and the switch  132 B will return to an open state. 
         [0058]    In the context of operating a fuel transfer pump, it is assumed that the user must physically actuate some component to initiate operation of the pump, and thus must be proximate the pump at least when it is initiated. In the one specific implementation, the user must insert a nozzle into the tank or container to be filled and squeeze a pump lever to cause fuel to flow. Instead of or in conjunction with such requirements dictating that a user must be physically proximate, the system can be programmed to allow operation only if a user is within a predetermined range, i.e., only if a user remains within Bluetooth operation range, as one example. In the described example, if the Bluetooth link with the pump or the meter is interrupted, then the associated device is shut off. The user must re-start the transaction, including re-establishing the Bluetooth links. 
         [0059]    In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. We therefore claim as our invention all that comes within the scope and spirit of these claims.