JP5891633B2 - Communication terminal, wireless communication system, and program - Google Patents

Description

  The present invention relates to a communication terminal that performs wireless communication, a wireless system including the communication terminal, and a program.

  2. Description of the Related Art Conventionally, an order entry system is known in which a customer service staff has a handy terminal for taking orders at restaurants and other restaurants, and notifies the cooking staff of cooking instructions for order items from the handy terminal via a controller. ing.

  The order entry system includes at least one handy terminal, a controller, and a printer. The handy terminal is held by the customer service staff one by one, and order information related to customer orders is input. The inputted order information is transmitted from the handy terminal to the controller by wireless communication and printed by the printer. The cooking staff visually confirms the printed order information and performs cooking.

  In an order entry system having a plurality of handy terminals, communication between each handy terminal and the controller is performed by wireless communication with a specific low power, and the controller can simultaneously communicate with one of the plurality of handy terminals. That is, the controller wireless communication is one line. Here, with reference to FIG. 10, the radio | wireless communication in the order entry system which has the handy terminal 20D and the controller 10D is demonstrated. FIG. 10 is a diagram illustrating the electric field strength in wireless communication between the handy terminal 20D and the controller 10D.

  The handy terminal 20D includes a main CPU (Central Processing Unit) and a wireless communication module connected to the CPU via a serial interface. The wireless communication module is a chipset module that performs wireless communication. The main functions of the wireless communication module are (I) ambient radio wave detection function, (II) data transmission function, (III) confirmation reception function, (IV) data reception function, (V) data retransmission function, It is.

  The peripheral radio wave detection function (I) is a function that detects the electric field strength of the peripheral radio wave and temporarily stops data transmission when it is detected. The data transmission function (II) is a function for transmitting various types of transmission target data (transmission data) to a destination controller. The confirmation reception function (III) is a function for receiving confirmation data (telegram) for transmission data transmitted by the data transmission function from a destination controller. This confirmation data is an ACK indicating that the transmission data has been successfully received. The data receiving function (IV) is a function for receiving various data (received data) from the transmission source controller. (V) Retransmission (retry) function is used to transmit the transmission data to the destination controller when the detection of the peripheral radio wave by the peripheral radio wave detection function fails or when the confirmation reception function does not receive the confirmation data. This is a function for retrying the operation.

  The main CPU of the handy terminal 20D realizes wireless communication by transferring various commands and transmission / reception data to / from the wireless communication module in cooperation with an application program for wireless communication. That is, when viewed from the main CPU, the processing in the wireless communication module is concealed and executed, so that stable wireless communication processing is guaranteed.

  As shown in FIG. 10, the communication range when data is transmitted from the handy terminal 20D to the controller 10D is concentric communication areas R1, R2, R3, R4, and R5 centering on the handy terminal 20D. Each width | variety of communication area | region R1, R2, R3, R4, R5 is 15-20 [m], for example. As the position of the controller 10D moves away from the handy terminal 20D (communication region R1 → R2 → R3 → R4), the electric field strength of the radio wave is −40 [dBm] → −60 [dBm] → −80 [dBm] → −100 It becomes weak like [dBm]. When the controller 10D is in the communication region R5, the electric field strength is, for example, −130 [dBm], which is equivalent to noise, and the handy terminal 20D can transmit data to the controller 10D but cannot receive data from the controller 10D. Become.

  In data transmission from the handy terminal 20D to the controller 10D, the handy terminal 20D outputs a transmission command of transmission data to the wireless communication module. When the transmission command is input, the wireless communication module detects the electric field strength of the surrounding radio wave, and if not detected, transmits the transmission data to the controller 10. If the confirmation data (ACK) cannot be received from the controller 10 within the time and the transmission data is repeatedly retransmitted (retry) and the confirmation data is received from the controller 10, the transmission is successful. Therefore, when the controller 10D is in the communication region R1, R2, R3, R4 and the radio wave environment is good and wireless transmission / reception is possible, the handy terminal 20D can transmit transmission data to the controller 10D.

  When the controller 10D is in the communication region R5 and the radio wave environment is bad and only wireless transmission is possible, the wireless communication module of the handy terminal 20D can transmit transmission data to the controller 10D but cannot receive confirmation data, and automatically Then, retransmission (retry) of transmission data is repeated a predetermined number of times.

  In addition, in specific low-power wireless communication, there is a known wireless communication system that effectively avoids the delay of transmission data when the radio wave environment is bad when transmitting transmission data from the transmission source communication device to the transmission destination communication device. (See Patent Document 1). In this wireless communication system, the transmission source communication device stores the transmission data when the radio wave environment is poor and data transmission is retried. The transmission data generated at the same time is collectively transmitted to the destination communication device.

JP-A-7-58680

  However, in FIG. 10, when the controller 10D is in the communication region R5 and the radio wave environment is bad and the wireless communication module of the handy terminal 20D repeatedly retries data transmission, the handy terminal 20D repeatedly radiates radio waves during the retry. For other handy devices, the radio wave environment was getting worse. This is because the handy terminal 20D being retried occupies one line of the same frequency (same channel) of the wireless communication of the controller 10D, and other handy terminals cannot communicate with the controller 10D during the retry.

  When a plurality of handy terminals perform data transmission simultaneously in such a radio wave environment, data transmission delays and retries may occur in a chain, which may significantly degrade communication speed and stability. Furthermore, there is a possibility that communication of other communication devices using the communication frequency of the handy terminal 20D or a frequency in the vicinity thereof may be hindered (having an adverse effect).

  Further, in the wireless communication system of Patent Document 1, although the transmission efficiency of a plurality of transmission data can be improved, when there are a plurality of communication terminals (handy terminals) having the same wireless communication frequency (channel), the radio wave environment is bad. Retrying is repeated in the same manner as before in one communication terminal, and there is a possibility that the communication speed and stability of a plurality of communication terminals may be significantly degraded.

  An object of the present invention is to stably perform communication by preventing a decrease in communication speed in a plurality of communication terminals that wirelessly communicate with a controller.

In order to solve the above problems, a communication terminal of the present invention provides:
A communication terminal that performs wireless communication with a controller that performs wireless communication with a plurality of communication terminals,
A wireless communication module that detects the electric field strength of the surrounding radio waves and wirelessly transmits data to the controller when the detected electric field strength of the surrounding radio waves is within a predetermined electric field strength;
A wireless transmission instruction for data to the wireless communication module is performed, a transmission processing time from the wireless transmission instruction for the data to a successful wireless transmission is measured, and the wireless communication module actually transmits a radio wave out of the measured transmission processing time. The carrier time , which is the time for transmitting, is calculated, the occupation rate indicating the ratio of the calculated carrier time to the measured transmission processing time is calculated, and the calculated occupation rate is equal to or less than a preset upper limit value. A control unit for controlling wireless communication of the wireless communication module;
Is provided.

  Advantageous Effects of Invention According to the present invention, it is possible to avoid the occupation of communication at the same frequency in a plurality of communication terminals that wirelessly communicate with the controller, prevent a decrease in communication speed in the plurality of communication terminals, and perform communication stably. it can.

It is a block diagram which shows the order entry system of embodiment of this invention. It is a block diagram which shows the function structure of a handy terminal. (A) is a figure which shows an order information input screen. (B) is a figure which shows the screen during transmission. It is a flowchart which shows the radio | wireless communication management process performed with a handy terminal (CPU). It is a flowchart which shows the occupation rate calculation process of a radio | wireless communication management process. It is a figure which shows the carrier time storage to a carrier time buffer. It is a flowchart which shows the carrier time calculation storage process of a radio | wireless communication management process. It is a figure which shows an example of the data transmission of a radio | wireless communication module. It is a flowchart which shows the radio | wireless communication process performed with a radio | wireless communication module (CPU). It is a figure which shows the electric field strength in radio | wireless communication with a handy terminal and a controller.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. The present invention is not limited to the illustrated example.

  Embodiments according to the present invention will be described with reference to FIGS. First, the apparatus configuration of the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a block diagram showing an order entry system 1 according to this embodiment. FIG. 2 is a block diagram showing a functional configuration of the handy terminal 20A.

  The order entry system 1 as a wireless communication system according to the present embodiment is installed in a restaurant such as a restaurant. The order entry system 1 inputs order information such as the item name and quantity of items ordered by the customer service staff such as waiters to the handy terminals 20A, 20B, and 20C, and prints the order information. This system notifies the cooking staff in the kitchen.

  The order entry system 1 includes a controller (controller box) 10, handy terminals 20A, 20B, and 20C as communication terminals, printers 30 and 40, a hub (HUB) 50, and an ECR (Electronic Cash Register) 60. Prepare.

  The store where the order entry system 1 is installed has a kitchen, a floor, and deshap. The kitchen is an area where cooking staff cook. The floor is an area where customer service staff who eat and receive orders are arranged. The deshap is an area that is located between the kitchen and the floor, where the customer service staff can enter, and the cooked items are transferred from the cooking staff to the customer service staff.

  The handy terminals 20A, 20B, and 20C are respectively carried by three customer service staff arranged on the floor. That is, three handy terminals 20A, 20B, and 20C can be used simultaneously. For example, the controller 10, the printer 40, and the hub 50 are arranged in a deshap. The printer 30 is disposed in the kitchen. The ECR 60 is disposed on the floor.

  The controller 10 is an information management device in the order entry system 1. The controller 10 has functions such as a communication function for performing communication with each device of the order entry system 1, a setting function for menu information, and a control function for printing of the printers 30 and 40.

  Each of the handy terminals 20A, 20B, and 20C is an OES (Order Entry System) terminal into which customer service staff inputs order information. However, the number of handy terminals in the order entry system 1 is not limited to three, and may be two or four or more.

  The printer 30 is a printer that prints information on the order item corresponding to the order information input from the handy terminals 20A, 20B, and 20C on the paper under the control of the controller 10. The cooking staff visually confirms the order item type and the number of items described on the paper printed by the printer 30, and cooks the order item.

  The printer 40 is a printer that prints information on the order item corresponding to the order information input from the handy terminals 20A, 20B, and 20C on paper and outputs it as a slip under the control of the controller 10. The customer service staff receives the cooked items from the cooking staff, visually checks the type and number of items ordered on the slip printed by the printer 40, and distributes the order items to the customers on the floor.

  The hub 50 is a communication network concentrator, and relays communication between the controller 10 and the printers 30 and 40 and the ECR 60. The ECR 60 is a device that performs a checkout process for a customer's meal. The ECR 60 has a function of receiving information for payment from the controller 10, a function of storing money for change or money paid by a customer, a function of printing and issuing a receipt, a function of registering sales data, and the like.

  Next, the internal functional configuration of the handy terminal 20A will be described with reference to FIG. The functional configuration of the handy terminals 20B and 20C is the same as the functional configuration of the handy terminal 20A, and a description thereof will be omitted.

  As shown in FIG. 2, the handy terminal 20 </ b> A includes a CPU 21 as a control unit, an operation unit 22, a RAM (Random Access Memory) 23, a display unit 24, a ROM (Read Only Memory) 25, and a wireless communication module. 26, a flash memory 27, a timer unit 28, and a power supply unit 29. Each part except the power supply part 29 of the handy terminal 20A is connected via a bus 29a. It is assumed that the CPU 21 and the wireless communication module 26 are connected by, for example, a serial interface of the bus 29a.

  The CPU 21 controls each part of the handy terminal 20A. The CPU 21 reads a designated program out of various programs from the ROM 25 and expands it in the RAM 23, and executes various processes in cooperation with the expanded program.

  The operation unit 22 receives an operation input of various information from the user (service staff) and outputs the operation information to the CPU 21. The RAM 23 is a volatile semiconductor memory and has a work area for storing various data and various programs.

  The display unit 24 includes a display panel such as an LCD (Liquid Crystal Display), and performs various displays according to display information input from the CPU 21. The ROM 25 is a read-only memory that stores various data and various programs. The ROM 25 stores a wireless communication management program 251.

  The wireless communication module 26 is a chipset module that performs wireless communication with the controller 10. The wireless communication module 26 includes a CPU 261, a RAM 262, a ROM 263, and a wireless communication unit 264. Each part of the wireless communication module 26 is connected via a bus 265.

  The CPU 261 controls each unit of the wireless communication module 26. The CPU 261 reads a designated program from among the various programs from the ROM 263, expands it in the RAM 262, and executes various processes in cooperation with the expanded program.

  The RAM 262 is a volatile semiconductor memory and has a work area for storing various data and various programs. The ROM 263 is a read-only semiconductor memory that stores various data and various programs. The ROM 263 stores a wireless communication program 2631 and setting information. The setting information is a parameter for controlling the wireless communication module 26.

  The wireless communication unit 264 includes an antenna, a modulation unit, a demodulation unit, a signal processing unit, and the like, and performs wireless communication with the controller 10. The wireless communication unit 264 performs signal processing on information to be transmitted by the signal processing unit, modulates the signal processed transmission signal by the modulation unit, and outputs the modulated signal from the antenna as a radio wave. The wireless communication unit 264 receives the radio wave output from the controller 10 by an antenna, demodulates the received signal by the demodulation unit, and performs signal processing on the demodulated signal by the signal processing unit to receive information.

  Similar to the wireless communication module of the handy terminal 20D described in the related art, the wireless communication module 26 includes (I) an ambient radio wave detection function, (II) a data transmission function, (III) a confirmation reception function, and (IV And (V) a data retransmission function.

  The flash memory 27 is a non-volatile semiconductor memory that stores various information in a readable and writable manner. The flash memory 27 stores a device ID as identification information of the handy terminal 20A. The timer unit 28 is an RTC (Real Time Clock) that has a timer circuit that counts the current time, and outputs the current time information clocked by the timer circuit to the CPU 21.

  The power supply unit 29 is a secondary battery such as a lithium battery, and supplies power to each unit of the handy terminal 20A. The power supply unit 29 may be a primary battery such as an alkaline battery.

  Next, the operation of the order entry system 1 will be described with reference to FIGS. FIG. 3A is a diagram showing an order information input screen 241. FIG. 3B is a diagram showing a screen 242 during transmission. FIG. 4 is a flowchart showing a wireless communication management process executed by the handy terminal 20A (CPU 21 thereof). FIG. 5 is a flowchart showing the occupation rate calculation process of the wireless communication management process. FIG. 6 is a diagram showing the storage of the carrier time X in the carrier time buffers Y1, Y2, Y3, Y4, Y5, Y6. FIG. 7 is a flowchart showing the carrier time calculation storage process of the wireless communication management process. FIG. 8 is a diagram illustrating an example of data transmission of the wireless communication module. FIG. 9 is a flowchart showing wireless communication processing executed by the wireless communication module 26 (CPU 261 thereof).

  A wireless communication management process executed by the CPU 21 of the handy terminal 20A will be described with reference to FIGS. First, with reference to FIG. 3A and FIG. 3B, processing that is a premise of the wireless communication management processing will be described.

  In the order entry system 1, when a customer enters the store and sits at a table during the business hours of the store, the customer service staff places an order for the customer's items (food, drinks, etc.). Here, an example will be described in which the customer service staff possessing the handy terminal 20A takes an order, but the same processing is performed on the handy terminals 20B and 20C.

  It is assumed that the frequency (channel) of wireless communication of the handy terminal 20A is set in advance by, for example, an operation input by the user via the operation unit 22, and is stored in the flash memory 27 as the set frequency. This set frequency is set to the same value for all handy terminals 20A, 20B, and 20C of the order entry system 1. Further, this set frequency is preferably set so as not to be the same frequency (channel) as the frequency of neighboring wireless communication such as an order entry system of a neighboring store.

  The customer service staff operates the operation unit 22 of the handy terminal 20A to activate the order information input process. In the order information input process, for example, an order information input screen 241 shown in FIG. 3A is displayed on the display unit 24, and input of order information related to an item ordered by the customer is accepted via the operation unit 22. The order information includes the type (identification information) of the ordered item, its quantity, identification information of the table on which the ordered customer is seated, and the like.

  The order information input from the handy terminal 20A is wirelessly transmitted to the controller 10. The controller 10 receives order information from the handy terminal 20A. Then, the controller 10 causes the printer 30 to print the received order information. The cooking staff visually checks the order information printed by the printer 30 and starts cooking.

  Further, the controller 10 causes the printer 40 to print the received order information as a slip. The customer service staff looks at the slip printed by the printer 40 to check whether the cooked item is correct, and if there is no mistake, distributes the cooked item to the corresponding table together with the slip. . The wireless communication management process shown in FIG. 4 is a process for performing communication management when wirelessly transmitting the above order information to the controller 10.

  In the handy terminal 20A, the CPU 21 is read from the ROM 25 and appropriately expanded in the RAM 23 when triggered by the input of the order information by the customer service staff via the operation unit 22 and the instruction information wireless transmission instruction. The wireless communication management process is executed in cooperation with the wireless communication management program 251. It is assumed that the operation-input order information is stored in the RAM 23.

  First, the CPU 21 displays a transmission screen indicating that order information is being transmitted on the display unit 24 (step S11). In step S11, for example, a transmission screen 242 shown in FIG. 3B is displayed on the display unit 24.

  Then, the CPU 21 selects and acquires item information of one unselected item from the operation-input order information stored in the RAM 23 (step S12). For example, when step S12 is executed for the first time, information (such as table identification information) other than item information in the order information is also acquired.

  Then, the CPU 21 copies the item information acquired in step S12 to the end of the transmission buffer as a buffer of order information to be transmitted stored in the RAM 23 (step S13).

  Then, the CPU 21 determines whether or not the operation-input order information stored in the RAM 23 includes the next item information not selected in step S12 (step S14). When there is next item information (step S14; YES), the process proceeds to step S12. When there is no next item information (step S14; NO), all item information of the order information input by the operation has been selected, and the CPU 21 issues a module initialization command for initializing the wireless communication module 26 to the wireless communication module. 26 (step S15).

  Then, the CPU 21 reads the set frequency from the flash memory 27, and outputs a frequency setting command for setting the frequency of the wireless communication of the wireless communication module 26 to the read set frequency to the wireless communication module 26 (step S16). The frequency setting command includes a set frequency. Then, the CPU 21 reads the device ID from the flash memory 27, and outputs a device ID setting command for setting the read device ID to the wireless communication module 26 to the wireless communication module 26 (step S17). The device ID setting command includes a device ID.

  Then, the CPU 21 calculates the occupation rate in the wireless communication with the controller 10 by using the carrier time of a predetermined time (a predetermined number of carrier time buffers) from the current time calculated in step S24 described later and stored in the RAM 23. An occupancy ratio calculation process is executed (step S18). The occupation rate calculation process in step S18 will be described later in detail. The occupation ratio is a ratio of an actual transmission time in a predetermined measurement time in the wireless communication module 26. The carrier time is a time for actually transmitting a radio wave among transmission processing times for transmitting transmission data. Further, in the occupation ratio calculation process in step S18, when wireless communication is possible, a communication enable flag is set (stored) in the RAM 23 to enable wireless communication of the wireless communication module 26, and wireless communication is impossible. In this case, it is assumed that a communication disable flag indicating that the wireless communication of the wireless communication module 26 is disabled is set in the RAM 23.

  And CPU21 discriminate | determines whether the communicable flag is set to RAM23 by the occupation rate calculation process in step S18 (step S19). When the communicability flag is not set (step S19; NO), the occupation ratio is high, the communication impossibility flag is set in the RAM 23, and the CPU 21 ends the wireless communication process. That is, wireless communication is stopped.

  When the communicable flag is set (step S19; YES), the occupation rate is normal, and the CPU 21 reads the order information transmission buffer stored in the RAM 23 (step S20). Then, the CPU 21 acquires the current time information from the time measuring unit 28, stores the current time information in the RAM 23 as the start time of the transmission processing time, and starts measuring the transmission processing time used for calculating the carrier time (step S21). ).

  Then, the CPU 21 outputs to the wireless communication module 26 a transmission command for causing the wireless communication module 26 to transmit the data in the transmission buffer to the controller 10 as transmission data, and the data in the transmission buffer (step S22). Then, the CPU 21 ends the measurement of the transmission processing time in response to the input of the confirmation data (ACK) indicating that the transmission data is received by the controller 10 from the wireless communication module 26, and the current time from the time measuring unit 28. The end time of the transmission processing time is acquired using the information, and the transmission processing time from the start time to the end time of the transmission processing time is stored in the RAM 23 (step S23).

  Then, the CPU 21 calculates a carrier time for wireless communication of the wireless communication module 26 and executes a carrier time calculation storage process for storing it in the RAM 23 (step S24), and ends the wireless communication management process. The carrier time calculation storage process in step S24 will be described later in detail.

  Next, the occupation rate calculation process in step S18 of the wireless communication management process will be described with reference to FIGS. The carrier time calculated by the carrier time calculation storage process in step S24 is stored in a plurality of carrier time buffers in the RAM 23. For example, as shown in FIG. 6, a predetermined number (6 in this case) of past continuous carrier time buffers Y1, Y2, Y3, Y4, Y5, Y6 from the current time t1 at the elapsed time t are updated at any time. And stored in the RAM 23. Each of the carrier time buffers Y1, Y2, Y3, Y4, Y5, and Y6 is a buffer of unit time T1 in which the measurement time T is divided into six. The measurement time T is the measurement time for which the occupation rate is calculated, and is set in advance and stored in the flash memory 27. In addition, the start time and end time are updated and set together with each carrier time buffer and stored in the RAM 23.

  The order of the carrier time buffers Y1, Y2, Y3, Y4, Y5, and Y6 is the elapsed order of the elapsed time t. In the carrier time buffers Y1, Y2, Y3, Y4, Y5, and Y6, the values of the carrier times generated during the period from the start time to the end time in the carrier time calculation storage process in step S24 are stored.

  If the carrier time buffers Y1, Y2, Y3, Y4, Y5, and Y6 are a predetermined number (6 in this case) of ring buffers with the latest carrier time buffer including the current time t1, the storage capacity of the RAM 23 is reduced. This is preferable. Further, the number of carrier time buffers within the measurement time T is not limited to six.

  As shown in FIG. 5, first, the CPU 21 acquires current time information from the time measuring unit 28, and a predetermined number (for example, six) of carrier time buffers corresponding to past measurement times T from the current time information in the RAM 23. One unselected carrier time buffer is selected, and the value of the carrier time stored in the selected carrier time buffer is read and acquired (step S31). Then, the CPU 21 adds the value of the carrier time of the selected carrier time buffer acquired in step S31 to the occupation time Tw (step S32).

  Then, the CPU 21 determines whether or not there is an unselected carrier time buffer in step S31 (step S33). When there is an unselected carrier time buffer (step S33; YES), the process proceeds to step S31. However, in this transition, the current time information in step S31 is not updated. When there is no unselected carrier time buffer (step S33; NO), the occupation times of all the carrier time buffers are acquired, and the CPU 21 reads and acquires the measurement time T from the flash memory 27 (step S34).

Then, the CPU 21 uses the occupation time Tw calculated in steps S31 to S33 and the measurement time T acquired in step S34 to calculate the occupation rate W by the following equation (1) (step S35).
W = 100 × Tw / T (1)

  Then, the CPU 21 reads and acquires the occupation rate upper limit Wm stored in the flash memory 27 (step S36). The occupation rate upper limit Wm is preset and stored in the flash memory 27, and is a threshold value of the occupation rate W for determining whether or not the wireless communication module 26 can perform wireless communication.

  Then, the CPU 21 determines whether or not the occupation rate W calculated in step S36 is within the occupation rate upper limit Wm (step S37). When the occupation rate W is within the occupation rate upper limit Wm (step S37; YES), the CPU 21 sets a communication enable flag in the RAM 23 (standing) (step S38), and ends the occupation rate calculation process. When the occupation rate W exceeds the occupation rate upper limit Wm (step S37; NO), the CPU 21 sets a communication impossible flag in the RAM 23 (standing) (step S39), and ends the occupation rate calculation process.

  Here, a specific example of the occupation rate W calculation in the occupation rate calculation process will be described with reference to FIG. As shown in FIG. 6, in steps S21 to S24 of the wireless communication process, the carrier time X1 is calculated at the transmission processing time Z1 along the elapsed time t, and stored in the carrier time buffer Y1. Similarly, it is assumed that carrier times X2 and X3 are calculated from the transmission processing times Z2 and Z3 and stored in the carrier time buffer Y3.

  It is assumed that the unit time T1 is 30 [s], the measurement time T is 180 [s], and the occupation rate upper limit Wm is set to 10 [%]. The carrier times X1, X2, and X3 are 7 [s], 3 [s], and 2 [s].

  Then, after the first data transmission, the carrier time X1 = 7 [s] is stored in the carrier time buffer Y1. After the second data transmission, the carrier time X2 = 3 [s] is stored in the carrier time buffer Y3. Then, after the third data transmission, 3 [s] + carrier time X3 = 5 [s] is stored in the carrier time buffer Y3. The values of the carrier time buffers Y2, Y4, Y5, Y6 are all 0.

  When such wireless communication is performed, the occupation rate W at the current time t1 is calculated in step S35 of the occupation rate calculation process. Occupancy rate W = 100 × Tw / T = 100 × (7 + 0 + 5 + 0 + 0 + 0) / 180≈7 [%]. Since the occupation rate W = 7 [%] is within the occupation rate upper limit Wm = 10 [%] (step S37; YES), the communicability flag is set in step S38 of the occupation rate calculation process, and in the next wireless communication Steps S20 to S24 of the wireless communication process are executed.

  Next, the carrier time calculation storage process in step S24 of the wireless communication management process will be described with reference to FIGS. The periphery detection time B, which is the time for detecting the electric field strength of the radio waves around the handy terminal 20A, and the baud rate of the wireless communication of the wireless communication module 26 are fixed values and are preset and stored in the flash memory 27. It shall be.

  First, the CPU 21 reads and acquires the transmission processing time Z acquired in steps S21 to S23 of the wireless communication management process from the RAM 23 (step S41). Then, the CPU 21 reads and acquires the periphery detection time B from the flash memory 27 (step S42). Then, the CPU 21 reads out and acquires the baud rate for wireless communication from the flash memory 27 (step S43).

Then, the CPU 21 refers to the transmission data after transmission in step S20 of the transmission buffer in the RAM 23, and acquires the transmission data amount (step S44). Then, the CPU 21 calculates the ideal value of the data transmission time D by the following equation (2) using the transmission data amount acquired in step S44 and the baud rate acquired in step S43, and stores it in the RAM 23 (step S45). ).
D = transmission data amount / baud rate (2)

  Then, the CPU 21 calculates the carrier time X using the transmission processing time Z acquired in step S41, the peripheral detection time B acquired in step S42, and the data transmission time D (its ideal value) calculated in step S45. Approximate calculation is performed and stored in the RAM 23 (step S46). The approximate calculation of the carrier time X in step S46 will be described later in detail.

  Then, the CPU 21 acquires current time information from the time measuring unit 28 (step S47). Then, the CPU 21 selects one unselected carrier time buffer from the plurality of carrier time buffers in the RAM 23 (step S48). Then, the CPU 21 acquires the start time and end time of the carrier time buffer selected in step S48 from the RAM 23 (step S49).

  Then, the CPU 21 determines whether or not the current time information acquired in step S47 is within the carrier time buffer selected in step S48 (from the start time acquired in step S49 to the end time) (step S50). . If the current time information is not in the selected carrier time buffer (step S50; NO), the CPU 21 determines whether or not there is a next carrier time buffer that is not selected in step S48 (step S51).

  If there is a next carrier time buffer (step S51; YES), the process proceeds to step S48. When there is no next carrier time buffer (step S51; NO), the CPU 21 performs an error process (step S52), and ends the carrier time calculation storage process.

  When the current time information is in the selected carrier time buffer (step S50; YES), the CPU 21 adds the carrier time X calculated in step S46 to the value of the carrier time buffer in the RAM 23 being selected in step S48. (Step S53), and the carrier time calculation storage process is terminated.

  Here, the approximate calculation of the carrier time X in step S46 of the carrier time calculation storage process will be described with reference to FIG. As shown in FIG. 8, the time from the measurement start time of the transmission processing time Z in steps S21 to S24 of the wireless communication management process to the time when transmission data transmission from the wireless communication module 26 to the controller 10 is finally successful. It is.

  In the transmission processing time Z, the wireless communication module 26 fails to detect the surroundings in the first n times (n: any integer) and the setting of commands such as a transmission command by the wireless communication processing described later (failure of surrounding detection). a) Next, it is estimated that data transmission fails m times (m: any integer) (data transmission failure b), and data transmission succeeds once (data transmission success c). In other words, measurement of the transmission processing time Z is started in step S21, data transmission retransmission (retry) occurs due to the peripheral detection failure a and data transmission failure b, and transmission is performed in step S23 according to the last data transmission success c. The measurement of the processing time Z ends.

  A time required for setting a command such as a transmission command is a command processing time A. The peripheral detection failure a includes a peripheral detection time B and a waiting time C. The peripheral detection time B is the set value acquired in step S42. The waiting time C is a waiting time from the end of the peripheral detection time B to the detection of the next peripheral wireless radio wave after the detection of the peripheral wireless radio wave (its electric field strength) at the peripheral detection time B fails. The waiting time C is a random value, and for example, the average value is about 300 [ms].

  The data transmission failure b includes a peripheral detection time B, a data transmission time D, and a confirmation data waiting failure time E. The data transmission time D is an actual value of the data transmission time D for which the ideal value is calculated in step S45. The confirmation data waiting failure time E is the maximum waiting time for waiting for confirmation data (ACK) from the controller 10 after the wireless communication module 26 transmits transmission data to the controller 10. That is, if the confirmation data (ACK) is not transmitted even after waiting for the confirmation data waiting failure time E, data transmission fails.

  The data transmission success c includes a surrounding detection time B, a data transmission time D, and a confirmation data waiting success time Es. The confirmation data waiting success time Es is a waiting time until the wireless communication module 26 receives the confirmation data (ACK) from the controller 10 after transmitting the transmission data to the controller 10. The confirmation data waiting success time Es is shorter than the confirmation data waiting failure time E.

In the example of FIG. 8, the transmission processing time Z is calculated by the following equation (3).
Z = A + n (B + C) + m (B + D + E) + (B + D + Es) (3)
The carrier time X is estimated from Z in equation (3). As a premise, since the wireless communication module 26 does not have a timer (RTC), it is not possible to accurately know the number of times the data transmission time D has occurred from the transmission processing time Z. In addition, in the approximate calculation of the carrier time X, it is a safe approximation to calculate that a large amount of data transmission time D has occurred. This is because if the number of occurrences of the data transmission time D is increased, the occupation rate W will eventually increase, so that it becomes easier to go to NO in step S19 of the wireless communication management process, and this will work to reduce the occupation of wireless communication. is there.

In equation (3), (B + D + E) of data transmission failure b is approximated as (B + D + Es) of data transmission success c (ie, E≈Es), and the following equation (4) is obtained.
Z = A + n (B + C) + (m + 1) (B + D + Es) (4)

Then, when both sides of the formula (4) are divided by (B + D + Es), the following formula (5) is obtained.
Z / (B + D + Es) = {A + n (B + C)} / (B + D + Es) + (m + 1) (5)
The left side of Equation (5) is the number of transmissions indicating how many times data transmission success c (+ data transmission failure b) has been performed within the transmission processing time Z.

Here, the first term on the right side of the equation (5) may be ignored because the command processing time A is sufficiently small. If the confirmation data waiting success time Es is also sufficiently small, the following equation (6) is obtained.
Z / (B + D) = {n (B + C)} / (B + D) + (m + 1) (6)

  Here, if n (B + C) <(B + D), the first term on the right side of Equation (6) is ignored, and if n (B + C) ≧ (B + D), the first term on the right side of Equation (6) is transmitted. Will be included. The first term on the right side of Equation (6) is not actually the carrier time, but is an approximation of the safe direction described above. Then, the left side of Expression (6) is the number of transmissions of transmission data.

Therefore, the carrier time X is calculated by the following equation (7) by multiplying the data transmission time D and the number of transmissions.
X = D {Z / (B + D)} (7)
In step S46, the carrier time X is calculated by equation (7).

  Next, wireless communication processing executed by the CPU 261 of the wireless communication module 26 will be described with reference to FIG.

  The wireless communication process is a process for performing various processes such as actual wireless communication in accordance with various commands output by the wireless communication management process executed by the CPU 21. In the wireless communication module 26, triggered by the input of information from the CPU 21, the CPU 261 executes wireless communication processing in cooperation with the wireless communication program 2631 read from the ROM 263 and appropriately expanded in the RAM 262.

  First, the CPU 261 determines whether the information input from the CPU 21 is various commands (transmission command, frequency setting command, device ID setting command, transmission command) (step S61). When it is not various commands (step S61; NO), a wireless communication process is complete | finished.

  When it is various commands (step S61; YES), the CPU 261 analyzes which command is the various commands (step S62). Then, the CPU 261 determines whether or not the analysis result in step S62 is an initial setting command (step S63). When it is not an initial setting command (step S63; NO), the CPU 261 determines whether or not the analysis result of step S62 is a frequency setting command (step S64).

  When it is not a frequency setting command (step S64; NO), the CPU 261 determines whether or not the analysis result of step S62 is a device ID setting command (step S65). When it is not a device ID setting command (step S65; NO), the CPU 261 determines whether or not the analysis result of step S62 is a transmission command (step S66). If it is not a transmission command (step S66; NO), the wireless communication process ends.

  If it is an initial setting command (step S63; YES), the CPU 261 reads out setting information stored in the ROM 263 (step S67). Then, the CPU 261 stores the setting information read in step S67 in the RAM 262 (step S68), and ends the wireless communication process. In the subsequent processing, the setting information stored in the RAM 262 is used as appropriate.

  If it is a frequency setting command (step S64; YES), the CPU 261 stores the set frequency included in the frequency setting command in the RAM 262 (step S69), and ends the wireless communication process. If it is a device ID setting command (step S65; YES), the CPU 261 stores the device ID included in the device ID setting command in the RAM 262 (step S70), and ends the wireless communication process.

  When it is a transmission command (step S65; YES), the CPU 261 receives transmission data corresponding to the transmission command from the CPU 21, and stores the transmission data in the RAM 262 (step S71). Then, the CPU 261 determines whether or not the number of retries for retransmission of transmission data (steps S74 and S77; the number of NO) is equal to or less than a predetermined value specified in advance (step S72). This default value is, for example, 16 to 20 times.

  If the number of retries is greater than the predetermined value (step S72; NO), the wireless communication process ends. When the number of retries is equal to or less than the predetermined value (step S72; YES), the CPU 261 detects the electric field strength of the radio wave of the surrounding set frequency using the wireless communication unit 264 (step S73). Then, the CPU 261 determines whether or not the electric field strength detected in step S73 is equal to or lower than a preset default electric field strength (step S74).

  When the detected electric field strength is larger than the predetermined electric field strength (step S74; NO), the process proceeds to step S72. When the detected electric field strength is equal to or lower than the predetermined electric field strength (step S74; YES), the CPU 261 is stored in the RAM 262 using the setting information and the setting frequency stored in the RAM 262 via the wireless communication unit 264. The transmitted transmission data and device ID are wirelessly transmitted to the controller 10 (step S75).

  Then, the CPU 261 wirelessly receives confirmation data (ACK) from the controller 10 via the wireless communication unit 264 (step S76). Then, the CPU 261 determines whether or not confirmation data (ACK) has been received in step S76 (step S77).

  If confirmation data (ACK) has not been received (step S77; NO), the process proceeds to step S72. When the confirmation data (ACK) is received (step S77; YES), the CPU 261 outputs the confirmation data (ACK) to the CPU 21 (step S78) and ends the wireless communication process. Step S78 corresponds to step S23 of the wireless communication management process of FIG.

  As described above, according to the present embodiment, in the order entry system 1, each of the handy terminals 20A to 20C transmits data to the controller 10, and when the data transmission to the controller 10 fails, the data transmission retry is performed. A wireless communication module 26 is provided. In addition, each of the handy terminals 20A to 20C issues a data wireless transmission instruction (transmission command output) to the wireless communication module 26, measures a transmission processing time from the data wireless transmission instruction to the data transmission success, The carrier time X that is the actual data transmission time of the measured transmission processing time is calculated, and the occupation rate W that indicates the ratio of the calculated carrier time X to the predetermined measurement time T is calculated. A CPU 21 that controls wireless communication of the wireless communication module 26 is provided so that the occupation ratio W is equal to or less than the occupation ratio upper limit Wm.

  For this reason, in the handy terminals 20A, 20B, and 20C that wirelessly communicate with the controller 10 at the same frequency, it is possible to prevent the occupation of the wireless communication at a high occupation rate of each handy terminal, and the communication speed in the handy terminals 20A, 20B, and 20C decreases Communication can be performed stably. In addition, since the occupation rate is calculated as the ratio of the carrier time in the transmission processing time, it is possible to calculate an accurate occupation rate that takes into account the time during which wireless communication has failed. In addition, it is possible to reduce (adverse effects) hindering communication of other devices that perform wireless communication in the vicinity of the set frequency of the handy terminals 20A, 20B, and 20C or in the vicinity thereof.

  Further, the handy terminals 20A, 20B, and 20C divide the measured transmission processing time Z, the peripheral detection time B for detecting the electric field strength of the surrounding radio waves, and the transmission data amount of the transmitted data by the baud rate of the wireless communication. Using the data transmission time D, the carrier time X is calculated by the approximate expression (7). Therefore, the carrier time X can be calculated easily and quickly, and the occupation rate W taking this carrier time into account can be calculated easily and quickly.

  The handy terminals 20A, 20B, and 20C store the carrier time buffers Y1, Y2, Y3, Y4, Y5, and Y6 in the RAM 23, and set the calculated carrier time X to the value in the carrier time buffer corresponding to the current time. The occupancy ratio W indicating the ratio occupied by the total value (occupation time Tw) of the carrier times X of all the carrier time buffers Y1, Y2, Y3, Y4, Y5, and Y6 in the measurement time is expressed by the formula (1 ). For this reason, the occupation ratio W can be calculated accurately and easily. Further, if the carrier time buffers Y1, Y2, Y3, Y4, Y5, and Y6 are ring buffers, the capacity of the carrier time buffer can be reduced.

  The handy terminals 20A, 20B, and 20C also instruct the wireless communication module 26 to wirelessly transmit data (output a transmission command) when the calculated occupancy W is equal to or less than the occupancy upper limit Wm, and the calculated occupancy When W becomes larger than the occupation ratio upper limit Wm, wireless transmission of data of the wireless communication module 26 is stopped. For this reason, wireless transmission of data with an occupation rate W larger than the occupation rate upper limit Wm can be reliably prevented.

  The order entry system 1 includes handy terminals 20A, 20B, and 20C and a controller 10. For this reason, it is possible to prevent a decrease in communication speed in the handy terminals 20A, 20B, and 20C in the order entry system 1, and to perform communication stably.

  The description in the above embodiment is an example of a communication terminal, a wireless communication system, and a program according to the present invention, and the present invention is not limited to this.

  In the above-described embodiment, the order entry system 1 is configured to include one controller 10, but the present invention is not limited to this. For example, the order entry system may have a multi-access point function. This order entry system includes a plurality of controllers having different radio communication frequencies (channels). Each handy terminal searches and accesses a controller having a good radio wave condition (of a frequency not occupied by wireless communication) among a plurality of controllers. By calculating the occupancy rate of the handy terminal and controlling the wireless communication of this multi-access point function order entry system, wireless communication with a high occupancy rate of one handy terminal for one controller Can be prevented, a decrease in communication speed in a plurality of handy terminals can be prevented, and communication can be performed stably.

  In the above embodiment, the handy terminals 20A, 20B, and 20C have been described as the communication terminals, but the present invention is not limited to this. For example, the communication terminal may be another communication terminal such as a table terminal that is installed on a table and receives an input of customer order information and wirelessly transmits it to the controller.

  In addition, it goes without saying that the detailed configuration and detailed operation of each component of the order entry system in the above embodiment can be appropriately changed without departing from the spirit of the present invention.

Although the embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, but includes the scope of the invention described in the claims and the equivalents thereof.
The invention described in the scope of claims attached to the application of this application will be added below. The item numbers of the claims described in the appendix are as set forth in the claims attached to the application of this application.
[Appendix]
<Claim 1>
A communication terminal that performs wireless communication with a controller that performs wireless communication with a plurality of communication terminals,
A wireless communication module that performs wireless transmission of data to the controller and performs wireless transmission retry of the data when wireless transmission of data to the controller fails.
A carrier that performs a wireless transmission instruction of data to the wireless communication module, measures a transmission processing time from the wireless transmission instruction of the data to a successful wireless transmission, and is an actual data transmission time of the measured transmission processing time Calculating time, calculating an occupation ratio indicating a ratio of the calculated carrier time in a predetermined measurement time, and performing wireless communication of the wireless communication module so that the calculated occupation ratio is equal to or less than a preset upper limit value And a control unit that controls the communication terminal.
<Claim 2>
The wireless communication module detects electric field strength of surrounding radio waves, and when the detected electric field strength is within a predetermined electric field strength, performs wireless transmission of data to the controller,
The control unit includes the measured transmission processing time Z, the peripheral detection time B for detecting the electric field strength of the peripheral radio wave, and the data transmission time D obtained by dividing the data amount of the transmitted data by the baud rate of wireless communication. The communication terminal according to claim 1, wherein the carrier time is calculated by an equation of D {Z / (B + D)}.
<Claim 3>
A storage unit for storing a plurality of carrier time buffers obtained by dividing the measurement time over time;
The control unit adds the calculated carrier time to a value in the carrier time buffer corresponding to the current time, and a ratio of a total value of carrier times of all the carrier time buffers in the measurement time The communication terminal according to claim 1, wherein an occupancy ratio that indicates
<Claim 4>
The control unit instructs the wireless communication module to wirelessly transmit data when the calculated occupancy is equal to or less than the upper limit, and when the calculated occupancy is greater than the upper limit, The communication terminal according to claim 1, wherein the wireless transmission of data of the communication module is stopped.
<Claim 5>
A plurality of communication terminals according to any one of claims 1 to 4,
A wireless communication system comprising the controller.
<Claim 6>
A communication terminal computer that performs wireless communication with a controller that performs wireless communication with a plurality of communication terminals,
A wireless communication module that performs wireless transmission of data to the controller and performs retry of wireless transmission of the data when wireless transmission of data to the controller fails;
A carrier that performs a wireless transmission instruction of data to the wireless communication module, measures a transmission processing time from the wireless transmission instruction of the data to a successful wireless transmission, and is an actual data transmission time of the measured transmission processing time Calculating time, calculating an occupation ratio indicating a ratio of the calculated carrier time in a predetermined measurement time, and performing wireless communication of the wireless communication module so that the calculated occupation ratio is equal to or less than a preset upper limit value Control unit to control,
Program to function as.

1 Order entry system 10, 10D controller 20A, 20B, 20C, 20D Handy terminal 21 CPU
22 Operation unit 23 RAM
24 display unit 25 ROM
26 Wireless communication module 261 CPU
262 RAM
263 ROM
H.264 Wireless communication unit 265 Bus 27 Flash memory 28 Timekeeping unit 29 Power supply unit 29a Bus 30, 40 Printer 50 Hub 60 ECR

Claims (6)

A communication terminal that performs wireless communication with a controller that performs wireless communication with a plurality of communication terminals,
A wireless communication module that detects the electric field strength of the surrounding radio waves and wirelessly transmits data to the controller when the detected electric field strength of the surrounding radio waves is within a predetermined electric field strength;
A wireless transmission instruction for data to the wireless communication module is performed, a transmission processing time from the wireless transmission instruction for the data to a successful wireless transmission is measured, and the wireless communication module actually transmits a radio wave out of the measured transmission processing time. The carrier time , which is the time for transmitting, is calculated, the occupation rate indicating the ratio of the calculated carrier time to the measured transmission processing time is calculated, and the calculated occupation rate is equal to or less than a preset upper limit value. A control unit for controlling wireless communication of the wireless communication module;
A communication terminal comprising: A storage unit for storing a plurality of carrier time buffers obtained by dividing the measurement time over time;
The control unit adds the calculated carrier time to a value in the carrier time buffer corresponding to the current time, and a ratio of a total value of carrier times of all the carrier time buffers in the measurement time The communication terminal according to claim 1, which calculates an occupation ratio indicating   The control unit instructs the wireless communication module to wirelessly transmit data when the calculated occupancy is equal to or less than the upper limit, and when the calculated occupancy is greater than the upper limit, The communication terminal according to claim 1 or 2, wherein wireless transmission of data of the communication module is stopped. A plurality of communication terminals according to any one of claims 1 to 3,
A wireless communication system comprising the controller. A communication terminal computer that performs wireless communication with a controller that performs wireless communication with a plurality of communication terminals,
A wireless communication module that detects the electric field strength of a surrounding radio wave and wirelessly transmits data to the controller when the detected electric field strength of the surrounding radio wave is within a predetermined electric field strength;
A wireless transmission instruction for data to the wireless communication module is performed, a transmission processing time from the wireless transmission instruction for the data to a successful wireless transmission is measured, and the wireless communication module actually transmits a radio wave out of the measured transmission processing time. The carrier time , which is the time for transmitting, is calculated, the occupation rate indicating the ratio of the calculated carrier time to the measured transmission processing time is calculated, and the calculated occupation rate is equal to or less than a preset upper limit value. A control unit for controlling wireless communication of the wireless communication module,
Program to function as. A communication terminal that performs wireless communication with a controller that performs wireless communication with a plurality of communication terminals,
A wireless communication module that performs wireless transmission of data to the controller and performs wireless transmission retry of the data when wireless transmission of data to the controller fails.
A carrier that performs a wireless transmission instruction of data to the wireless communication module, measures a transmission processing time from the wireless transmission instruction of the data to a successful wireless transmission, and is an actual data transmission time of the measured transmission processing time Calculating time, calculating an occupation ratio indicating a ratio of the calculated carrier time in a predetermined measurement time, and performing wireless communication of the wireless communication module so that the calculated occupation ratio is equal to or less than a preset upper limit value And a control unit for controlling
The wireless communication module detects electric field strength of surrounding radio waves, and when the detected electric field strength is within a predetermined electric field strength, performs wireless transmission of data to the controller,
The control unit includes the measured transmission processing time Z, the peripheral detection time B for detecting the electric field strength of the peripheral radio wave, and the data transmission time D obtained by dividing the data amount of the transmitted data by the baud rate of wireless communication. , And a communication terminal that calculates the carrier time using the formula D {Z / (B + D)}.

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