JP6473494B1 - Battery-driven wireless communication system and synchronization correction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synchronization correction method in a system for performing bidirectional two-way wireless communication between a parent device and a child device.
A wireless communication sensor system includes a parent device and a child device driven by a battery. The parent device transmits a query including information on the sleep time to all the child devices. Each of the slave units 20 receives the query, calculates the sleep time based on the information about the sleep time included in the query, sets the calculated sleep time in the timer, operates with low power consumption during the sleep time, When the sleep time elapses, it operates in the normal operating state. Further, in the wireless communication sensor system 1, the base unit 10 has a function of determining a synchronization shift of the slave unit and automatically correcting the synchronization of the slave unit when the synchronization is lost.
[Selection] Figure 1

Description

  The present invention relates to a wireless communication system that performs wireless communication between a parent device and a plurality of child devices, and in particular, a method for reducing power consumption of a child device driven by a battery and a synchronization method between the parent device and the child device, and The present invention relates to a synchronization correction method.

  In a wireless communication system composed of a master unit and a plurality of slave units, when a battery is used as a power source for the slave unit, it is desired to suppress the power consumption as much as possible to increase the battery life. Battery life refers to the time available for a single charge. For example, the market demands that the battery life per charge be one year or longer, and the battery is required to be as small as possible (for example, an AA battery).

  For example, in the control system of the wireless communication apparatus disclosed in Patent Document 1, the slave unit can be switched by changing the wireless radio output level of the slave unit so that the master unit can receive with an intensity within the effective minimum reception intensity range. To reduce the transmission power of the battery and extend the battery life. In the wireless communication system of Patent Document 2, the remaining battery level is monitored, and if the remaining battery level is equal to or greater than a predetermined value, a first communication unit (for example, a wireless LAN communication unit) with relatively large power consumption is used. If the remaining battery level is smaller than a predetermined value, the operation of the first communication unit is stopped and the second communication unit (for example, the Bluetooth communication unit) with relatively low power consumption is operated. Thus, the battery-driven wireless communication device can be operated for a long time.

JP 2012-256882 A Japanese Patent Laid-Open No. 2006-167683

  In order to reduce the power consumption of the slave unit, there is a method of intermittently communicating between the master unit and the slave unit. In intermittent wireless communication, one-way communication in which the slave unit is dedicated to transmission and the master unit is dedicated to reception is generally used. The slave unit on the transmission side notifies the parent unit of the status every certain time (for example, at intervals of 1 second) or when an event occurs. Enter sleep mode. By such an intermittent communication method, power consumption can be significantly reduced as compared with a slave device that always communicates. Note that the low power consumption state is a sleep state called sleep, and is a state in which, for example, the clock speed is reduced, the operation of the microprocessor or the sensing unit is stopped, or normal operation cannot be performed. When the slave unit is in the sleep state, the slave unit cannot receive information from the master unit. Hereinafter, the low power consumption state is referred to as a sleep state.

  In the conventional intermittent communication method, power consumption can be reduced compared to a slave device that always communicates, but the slave device is a one-way communication in which the slave device is dedicated to transmission and the master device is dedicated to reception. It is impossible to determine whether or not is in the sleep state, and the parent device cannot transmit to the child device. Therefore, for example, when the slave unit is a sensor that performs some kind of detection, the master unit cannot instruct the slave unit to set or change the threshold value of the sensor, initialize the slave unit, or the like. When setting and changing the slave unit, the target slave unit must be disconnected from the system and worked offline, which is very complicated.

  On the other hand, in order to enable transmission from the parent device to the child device, it is possible to use bidirectional communication in which both devices transmit and receive information between the parent device and the child device. In the communication system, the handset is always in an operating state (also called a wake-up state). This is because the sleep cycle and the operation cycle cannot be synchronized between the parent device and the plurality of child devices, and the parent device cannot recognize that the child device is in the sleep state. Therefore, the battery life of the slave unit is shortened. As one example, the battery life of the slave unit in bidirectional communication is about 72 hours.

The present invention solves such a conventional problem, and enables a two-way communication by synchronizing a sleep cycle between a parent device and a child device, and improves a battery life of the child device. It is another object of the present invention to provide a wireless communication method.
Furthermore, an object of the present invention is to provide a wireless communication system and a wireless communication method having a function of correcting synchronization between a parent device and a child device.

  A wireless communication system according to the present invention includes a plurality of slave units driven by a battery and a master unit that performs wireless communication with the plurality of slave units, and the master unit relates to a sleep time of the slave unit. A transmission unit that transmits a query including sleep time information to all the slave units at a determined access cycle TM, a reception unit that receives a response message to the query, and synchronization of the slave units based on the reception status of the response message A determination unit that determines whether or not there is a deviation, and a correction unit that causes the transmission unit to transmit a query including the sleep time information for synchronization correction and the number of times of synchronization correction when it is determined that the synchronization is lost. Each of the plurality of slave units sets the sleep time based on the reception means for receiving the query from the master unit and the sleep time information included in the received query, and measures the sleep time. Sleep setting means, power control means to turn off the main circuit when setting the sleep time, and turn on the main circuit when the sleep time has passed, and send a response message to the query from the parent device A synchronization unit that sets the sleep time information for synchronization correction to the sleep setting unit for the number of times of synchronization correction when a query including the sleep time information for synchronization correction and the number of times of synchronization correction is received. A wireless communication system, comprising: a correction execution unit, wherein a time when a parent device accesses each of a plurality of child devices and a sleep time of the child devices are synchronized.

  In one embodiment, the sleep time x number of times for synchronization correction is substantially equal to the sleep time of one slave unit. In one embodiment, the parent device performs synchronization correction of the child device without changing the access cycle to the child device. In one embodiment, the period T at which the parent device accesses all the child devices is smaller than the sleep time interval for synchronization correction.

  According to the present invention, a wireless communication method in a wireless communication system including a plurality of slave units driven by a battery and a master unit that performs wireless communication with the plurality of slave units, the master unit relates to a sleep time of the slave unit A step of transmitting a query including sleep time information to all the slave units at a determined access cycle TM, a step of determining whether or not the slave units are out of synchronization based on the reception status of the response message, and synchronization And a step including transmitting a query including the sleep time information for synchronization correction and the number of times of synchronization correction to each of the plurality of slave units when transmitted from the master unit. Receiving the received query, setting the sleep time in the sleep timer based on the sleep time information included in the received query, and starting the sleep timer; Transmitting a response message to the communication device; turning off the main circuit during the sleep time after sending the response message; and turning on the main circuit when the sleep time elapses; and the synchronization correction And when the query including the sleep time information for synchronization and the number of times of synchronization correction is received, the sleep setting information is set in the sleep setting means for the number of times of the synchronization correction. The time for accessing each of the plurality of slave units is synchronized with the sleep time of the slave units.

  According to the present invention, the information related to the sleep time is transmitted from the parent device to the plurality of child devices, and each of the child devices is switched on / off of the sleep state based on the information related to the sleep time. Only the sleep state is canceled and the other states are in the sleep state, so that power consumption can be saved. Further, the parent device can transmit a query in synchronization with the time when the sleep state of the child device is released. Furthermore, according to the present invention, even if the synchronization of the slave unit is shifted (disconnected), the synchronization of the slave unit can be automatically corrected without changing the access cycle to the slave unit.

1 is a diagram illustrating an overall configuration of a wireless communication sensor system according to an embodiment of the present invention. It is a block diagram which shows the structure of the main | base station which concerns on the Example of this invention. It is a figure which shows the functional structural example of the communication control program of the main | base station which concerns on 1st Example of this invention. It is a figure which illustrates the format of the query information and the response message information from a subunit | mobile_unit. It is a figure which shows the function of the function code regarding sleep time. It is a block diagram which shows the functional structure of the subunit | mobile_unit which concerns on 1st Example of this invention. It is a figure which shows the circuit structure of the principal part of the subunit | mobile_unit which concerns on 1st Example of this invention. It is a block diagram which shows the functional structure of the control part which concerns on 1st Example of this invention. It is a timing chart explaining the whole operation | movement flow of the radio | wireless communication sensor system based on the Example of this invention. It is a timing chart explaining the whole operation | movement flow of the radio | wireless communication sensor system based on the Example of this invention. It is a timing chart figure explaining operation | movement of the subunit | mobile_unit which concerns on the Example of this invention. It is a figure which shows the operation | movement flow of the subunit | mobile_unit which concerns on the Example of this invention. It is a figure which shows the operation | movement flow of the subunit | mobile_unit which concerns on the Example of this invention. It is a figure which shows the operation | movement flow of the main | base station which concerns on the Example of this invention. It is a figure which shows the whole structure of the radio | wireless communication sensor system which concerns on the modification of the Example of this invention. It is a block diagram which shows the functional structure of the communication control program of the main | base station which concerns on 2nd Example of this invention. It is an operation | movement flow explaining the synchronous correction sequence of the main | base station which concerns on 2nd Example of this invention. It is a figure which shows the circuit structure of the principal part of the subunit | mobile_unit which concerns on 2nd Example of this invention. It is a block diagram which shows the functional structure of the control part which concerns on 2nd Example of this invention. 18A is a timing chart for explaining the operation when the parent device and the child device are synchronized, and FIG. 18B is for explaining the operation when the parent device and the child device are out of synchronization. FIG. 18C is a timing chart for explaining the operation when the synchronization correction of the parent device and the child device is performed.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. A wireless communication system according to the present invention includes a plurality of slave units driven by a battery, a master unit that performs bidirectional wireless communication with the plurality of slave units, and a control device (host device) connected to the master unit. Consists of including. The wireless communication system of the present invention can be preferably a monitoring system that monitors information detected by a plurality of slave units. The slave unit is arranged in a remote place and can detect various information in the remote place. For example, the handset can include a temperature sensor, a humidity sensor, a water level sensor, a soil moisture sensor, a rain gauge, a pressure sensor, an atmospheric pressure sensor, and the like. The master unit performs bidirectional wireless communication with the plurality of slave units, transmits information to the plurality of slave units, or receives information from the plurality of slave units. The parent device is further connected to a control device that controls the entire wireless communication system, and can send instructions to a plurality of child devices in accordance with instructions from the control device.

  FIG. 1 is a diagram showing an overall configuration of a wireless communication sensor system according to an embodiment of the present invention. The wireless communication sensor system 1 according to the present embodiment includes a parent device 10, a plurality of child devices 20a, 20b, 20c,... 20n (n is an integer of 2 or more) and a host device 30. . In addition, the whole subunit | mobile_unit 20a-20n is called the subunit | mobile_unit 20 generically.

  Base unit 10 performs bidirectional communication with each of a plurality of slave units 20 by radio (for example, a frequency band of 920 MHz). When the parent device 10 transmits a query (inquiry) Qa to the child device 20a, the child device 20a returns a response message Ra to the query Qa. Similarly, when the parent device 10 transmits a query Qb to the child device 20b, the child device 20b returns a response message Rb to the query Qb. In the system of the present embodiment, when the parent device 10 accesses the child devices 20, the number n of the child devices 20 is determined in a predetermined order (for example, in ascending order of addresses). Queries Qa, Qb, Qc,... Qn are transmitted to the slave units 20a, 20b, 20c,... 20n, and a response message is received from each slave unit. The subunit | mobile_unit 20 wakes up synchronizing with the period with the access from a main | base station, and suppresses that a battery is consumed as much as possible. Even if some of the slave units are disconnected, the master unit 10 can access the predetermined number n of slave units 20 without skipping the disconnected slave units. Make sure that the synchronization between the master and slave units is not lost.

  When receiving the query Q from the parent device 10, the child device 20 creates a response message R corresponding to the query Q and transmits it to the parent device 10. The subunit | mobile_unit 20 is operate | moved with a battery (battery), and has the sleep state (low power consumption state) which performs only minimum necessary operation | movement, and the normal operation state waked up from the sleep state. In a normal operation state, all the functions included in the child device can be operated completely, and some functions included in the child device can be operated in the low power consumption information.

  Host device 30 is connected to parent device 10 by wire or wirelessly. The host device 30 can be a computer device, a notebook computer, a portable communication terminal, a tablet communication terminal, or the like. The host device 30 gives necessary instructions to the parent device 10 and collects information on the child device 20 from the parent device 10 in order to monitor or control the entire system. The host device 30 may be connected to the parent device 10 via a network such as the Internet or an intranet.

  FIG. 2 is a block diagram illustrating an example of the configuration of the parent device according to the present embodiment. The base unit 10 includes an input unit 100 (for example, various switches and buttons attached to the base unit 10, touch panel input, power on / off switch, etc.), a wireless communication unit 110, an external connection unit 120, a storage unit 130, The display unit 140 and the control unit 150 are included. In addition, this structure is an illustration and the main | base station may include another structure.

  Wireless communication unit 110 includes a wireless module (hereinafter also referred to as WM) for performing bidirectional wireless communication with handset 20. Wireless communication between the parent device 10 and the child device 20 is performed using a protocol that allows the parent device 10 to access the plurality of child devices 20, and for example, a communication method of Modbus (registered trademark) protocol is adopted. In this communication method, only the parent device 10 can issue a query (inquiry), and the parent device 10 performs unicast communication for issuing a query to an addressed child device. Each of the child devices creates a response message in response to the query from the parent device, and transmits this to the parent device 10.

  The external connection unit 120 establishes a wired or wireless connection with the host device 30 or establishes a connection with another network or the like. The connection between the parent device 10 and the host device 30 is performed asynchronously with the wireless communication with the child device 20. The wired connection can be, for example, an RS232C cable, a USB cable, or a wired LAN, and the wireless connection can be WiFi (registered trademark), WiMAX, wireless LAN, or Bluetooth (registered trademark).

  The storage unit 130 can store various data such as a program executed by the control unit 150, a query to the child device 20, a response message from the child device 20, a command from the host device 30, and the like. The display unit 140 is a display medium such as a liquid crystal display attached to the parent device 10 and can display a warning message indicating the state of the parent device 10, a response message from the child device 20, connection information with an external device, and the like. it can.

  In a preferred embodiment, the control unit 150 includes a microcontroller or a microprocessor (MPU), and the control unit 150 executes a communication control program or sequence for controlling bidirectional wireless communication between the parent device 10 and the child device 20. Run.

  FIG. 3 is a diagram illustrating a functional configuration of a communication control program or sequence executed by the control unit 150. The communication control program (or communication control sequence) 200 includes a query creation unit 210, a sleep information setting unit 220, a query transmission unit 230, a response message reception unit 240, and a slave device information provision unit 250.

  The query creation unit 210 creates a query to be issued to each of the child devices 20. FIG. 4A shows a query transmission format. As shown in the figure, the query includes a device address, a function code, query data, and an error check.

  The device address is unique identification information assigned to each child device 20, and the parent device specifies the device address of the child device when accessing the child device 20. For example, when a query is transmitted to the slave unit 20a in FIG. 1, the device address of the slave unit 20a is specified, and when a query is transmitted to the slave unit 20b, the device address of the slave unit 20b is specified.

  The function code includes, for example, various commands according to the Modbus standard. For example, a command for reading the on / off status of the slave unit output, a command for reading the on / off status of the slave unit input, a command for reading the content held by the slave unit register, and a command for changing the register content of the slave unit Etc. Further, in this embodiment, an original function code Fn is provided as shown in FIG. The function code Fn is a command for instructing the slave unit to set the sleep time and polling. This function code Fn is always included when the parent device 10 accesses the child device 20.

  Various data can be included in the query data. For example, in addition to setting or changing the threshold value of the sensor of the slave unit, the sleep information necessary for setting the sleep time for the function code Fn is included. It is. The error check includes information for detecting and correcting transmission data errors.

  The sleep information setting unit 220 sets sleep information necessary for the slave unit 20 to set a sleep time. In one preferred example, the sleep information is a period T (hereinafter also referred to as a status notification interval) in which the parent device accesses all the child devices 20. When the number of slave units 20 is n, the master unit 10 accesses one slave unit at a time interval of T / n. The state notification interval T is instructed from the host device 30 to the parent device 10, but the parent device 10 can set the default value as the state notification interval T when there is no instruction.

  The query transmission unit 230 transmits, for example, queries created in ascending order of the addresses of the slave units (for example, in the order of the slave units 20a, 20b, 20c,..., 20n in FIG. 1) via the wireless communication unit 110 to all the child units. To the machine 20.

  The response message receiving unit 240 receives a response message transmitted from the child device 20 in response to the query. The transmission format of the response message is shown in FIG. The confirmation device address is the address of the child device that created the response message, the confirmation function code is the function code executed by the child device, and the response data is information including the content of the response to the query. The slave unit information providing unit 250 provides the response data received by the response message receiving unit 240 to the host device 30.

  Next, the subunit | mobile_unit 20 of a present Example is demonstrated. FIG. 6 is a block diagram showing a functional configuration of the slave unit 20. The subunit | mobile_unit 20 generally contains the sensor module 300, the radio | wireless communication module 310, the power supply module 320, and the control module 330. FIG. The sensor module 300 includes a sensor circuit for detecting necessary information at a position where the slave unit 20 is installed, a storage circuit for holding information detected by the sensor circuit, and the like. The wireless communication module 310 includes a communication circuit for performing bidirectional wireless communication with the parent device 10. The power supply module 320 includes a circuit that controls conveyance of power supplied from the battery to each unit. The control module 330 includes a circuit that controls the entire slave unit 20.

  FIG. 7 is a diagram illustrating a circuit configuration of a main part of the slave unit 20. In the drawing, a broken line indicates a power supply line, and a solid line indicates a signal line. Also, details of the sensor module 300 are not shown here.

  The subunit | mobile_unit 20 contains the secondary battery 400 which can be charged, and the battery 400 supplies the voltage VB (for example, 3.6-3.7V) to each part. That is, voltage VB from battery 400 is supplied to DC / DC converters 402 and 404, reset circuits 410 and 412, and sleep timer 420.

  When the voltage VB of the battery 400 is applied, the reset circuit 410 outputs a reset signal RESET1 for power-on reset to the power load control circuit 440 in response thereto. When the power load control circuit 440 receives the reset signal RESET 1, the power load control circuit 440 is reset to power-on, outputs an enable signal EN to the DC / DC converter 402, and operates the DC / DC converter 402. The DC / DC converter 402 converts the voltage VB of the battery 400 into a desired voltage V1, and the converted voltage V1 is supplied to the control unit 430 and the reset circuit 412. Upon receiving the voltage V1 from the DC / DC converter 402, the reset circuit 412 outputs a reset signal RESET2 for power-on reset to the control unit 430 in response thereto. When the control unit 430 receives the voltage V1 from the DC / DC converter 402 and receives the reset signal RESET2 from the reset circuit 410, the control unit 430 is reset to power-on and initializes the inside. The control unit 430 further initializes the wireless module 470 and outputs a reset signal RESET3 and a power-on signal PWRON for powering on the wireless module 470.

  On the other hand, the DC / DC converter 404 is operated by the voltage VB from the battery 400 and outputs the converted desired voltage V2 to the wireless module 470. The wireless module 470 is in a power-down mode only when the voltage V2 is input, but enters the power-on mode when the power-on signal PWRON from the control unit 430 is input as described above. When the wireless module 470 is in the power-on mode, the wireless module 470 can receive a query from the parent device 10. Further, the wireless module 470 can receive a command from the control unit 430, and can shift from the power-on mode to the sleep state and from the sleep state to the power-on mode by the command. When the wireless module 470 is in the sleep state, the power of the RF circuit of the wireless module 470 is turned off and the power consumption state is entered. When in the sleep state, the wireless module 470 cannot receive a query from the parent device 10.

  The sleep timer 420 can be operated by the voltage Vb from the battery 400. The sleep timer 420 monitors the sleep time of the control unit 430 by counting the sleep time of the slave unit 20. The sleep time of the sleep timer 420 is set by the control unit 430. In a preferred example, the control unit 430 calculates a sleep time based on the access cycle T included in the query of the parent device 10, sets the calculated sleep time Tslp in the sleep timer 420, and starts counting the sleep timer 420. .

  After transmitting the response message to the master unit, control unit 430 outputs a control signal STP for stopping the operation of DC / DC converter 402 to power load control circuit 440. When receiving the control signal STP, the power load control circuit 440 outputs a disable signal to the DC / DC converter 402, and the operation of the DC / DC converter 402 is stopped. As a result, the voltage V1 is not supplied to the control unit 430, and the control unit 430 is effectively turned off. In addition, when the sleep timer 420 counts the elapse of the sleep time, it outputs a time over signal TMO to the power load control circuit 440. When the power load control circuit 440 receives the time over signal TMO, the power load control circuit 440 outputs the enable signal EN to the DC / DC converter 402 again to operate the DC / DC converter 402. Thereby, the control part 430 will be in a power-on state.

  Address holding unit 450 holds the address of the slave unit and provides the address information to control unit 430. This address information is referred to, for example, when creating a response message to the query. The method of setting the address in the address holding unit 450 is arbitrary, but the address can be set or changed by a dip switch or the like, for example.

  When the wireless module 470 receives a query addressed to itself, the interrupt control unit 460 outputs an interrupt signal INT to the control unit 430 to wake up the control unit 430 in the sleep state.

  Next, main functions of the control unit 430 will be described. As shown in FIG. 8, the control unit 430 includes a CLIE receiving unit 500, a function executing unit 510, a sleep time calculating unit 520, a sleep time setting unit 530, a sleep / startup executing unit 540, a response message creating unit 550, and a response message transmission. Part 560 and the like. These functions may be executed by any one of software (program), hardware, or a combination of software and hardware. When the control unit 430 includes, for example, a microprocessor MPU including a ROM and a RAM, the main functions described above can be operated by executing a program in the ROM or the RAM.

  The query receiving unit 500 receives a query addressed to itself via the wireless module 470. In one example, the control unit 430 enters a sleep state by executing a program command (sleep command). When the control unit 430 is in the sleep state, the wireless module 470 receives a query addressed to itself from the base unit 10; The wireless module 470 causes the interrupt control unit 460 to output an interrupt signal INT. When receiving the interrupt signal INT, the control unit 430 wakes up from the sleep state. The wireless module 470 extracts a device address included in the query and determines whether the query is for the own station.

  When the query is received by the query receiving unit 500, the function execution unit 510 executes the function code included in the query. For example, although not shown here, operations such as setting a threshold value of a sensor included in the slave unit and reading a value detected by the sensor from a register are performed. Since the query always includes the function code Fn shown in FIG. 5, the function execution unit 510 causes the sleep time calculation unit 520 to calculate the sleep time.

The sleep time calculation unit 520 calculates the sleep time Tslp based on the access cycle T (state notification interval T) included in the query. The sleep time Tslp is calculated by the following formula. Here, Trst is the reset time inside the slave unit, Tini is the initialization time inside the slave unit, Trcv is the transmission time of the master unit + the reception time of the slave unit, and Tst is the time between the sleep timer setting and the timer start. The times of Trst, Tini, Trcv, and Tst are previously stored in a register or the like as default values, for example. However, the master unit can change the times of Trst, Tini, Trcv, and Tst stored in the register according to a desired function code.

  The sleep time setting unit 530 sets the sleep time Tslp calculated via the signal line SLT in the sleep timer 420. When the sleep time is set, the sleep timer 420 starts counting, and outputs a time over signal TMO to the power load control circuit 440 when the count ends.

  The sleep / startup execution unit 540 puts the control unit 430 into a sleep state according to a predetermined operation sequence. In one example, the sleep / startup execution unit 540 enters a sleep state by executing a sleep command of a program. When the control unit 430 enters a sleep state, for example, a counter or a clock included in the control unit 430 is turned off, and the control unit 430 enters a low power consumption state. In addition, when the interrupt signal INT is input from the interrupt control unit 460, the sleep / startup execution unit 540 executes a wakeup command and starts up the control unit 430 from the sleep state.

  The response message creation unit 550 creates a response message for the query. For example, if the query is a request for a sensor detection value, the response message creation unit 550 creates a response message including the sensor detection value. Response message transmission unit 560 returns the created response message to the parent device. Note that the transmission format of the response message is as shown in FIG.

  The host device 30 instructs the parent device 10 to set or change the threshold value of the sensor of the child device 20, notifies the state notification interval T, or the child device 20 provided from the parent device 10. The content of the response message is received. Here, although parent device 10 and host device 30 are configured separately, they may be configured as one device.

Next, the operation of the wireless communication sensor system 1 according to the embodiment of the present invention will be described. FIGS. 9A and 9B are diagrams illustrating operation timings of the slave unit to the slave unit when the master unit 10 and the four slave units # 1, # 2, # 3, and # 4 perform wireless communication. In the figure, MPU represents the control unit 430, and W / M represents the wireless module 470. TM1, TM2, TM3, and TM4 are periods in which the slave units # 1, # 2, # 3, and # 4 are accessed, and TM1 = TM2 = TM3 = TM4 (referred to as TM when collectively referred to). FIG. 10 is a timing chart showing the operation of the slave unit at the time of system startup and normal operation. In the figure, P1 is an initialization operation, P2 is a reception operation, P3 is a sleep time setting operation, P4 is a response transmission operation, and t1, t2, t3, and t4 are times required for operations of P1, P2, P3, and P4. Represents. 11A and 11B show a detailed operation flow of the child device, and FIG. 12 shows a detailed operation flow of the parent device.

When starting up the wireless communication sensor system The host device 30 instructs the parent device 10 to set a cycle in which the parent device accesses all the child devices, that is, a state notification interval T. When there is no instruction from the host device 30, the parent device sets the default value as the state notification interval T. This setting is not limited to when the system is started up, but can be performed at any time.

  2. When the power is turned on (Power On), the MPUs of all the slave units initialize themselves, set only the WM to the operating state, and enter the sleep state.

  As shown in FIG. 11A, when the voltage VB from the battery 400 is supplied to the reset circuit 410, the reset circuit 410 outputs a reset signal RESET1 to the power load control circuit 440 (step S1), and the power load control circuit 440 It is activated. The DC / DC converter 402 is activated by the enable signal EN from the power load control circuit 440 (step S2), whereby the reset signal RESET2 is output from the reset circuit 412 to the control unit 430, and internal initialization of the control unit 430 is performed. (Step S3). The controller 430 outputs a power-on signal PWRON to the wireless module 470, and the wireless module 470 enters a power-on mode in response to the power-on signal PWRON. Further, the control unit 430 outputs a reset signal RESET3 to the wireless time module 470, and the wireless module 470 performs internal initialization in response to the reset signal RESET3. Next, the control unit 430 counts a certain time by an internal timer (for example, counts 62 ms), and when that time has elapsed (step S4), outputs a register initialization command to the wireless module 470, The wireless module 470 initializes the register in response to this command. When the initialization of the register is completed, the wireless module 470 transmits a message to that effect to the control unit 430, and the control unit 430 starts the reception monitoring timer operation (step S6). The state is entered (step S7). On the other hand, the wireless module 470 waits to receive a query from the parent device when the initialization of the register is completed.

  These aspects are also shown in FIG. 9A. That is, in the slave units # 1, # 2, # 3, and # 4, when the power is turned on, the MPU transitions to power on, wake up, and sleep, and W / M wakes up.

  FIG. 10 shows an example in which the power-on time is different between the slave unit # 1 and the slave units # 2, # 3, and # 4. When power is turned on in slave units # 1, # 2, # 3, and # 4, initialization operation P1 is performed.

  3. The base unit 10 adds the status notification interval T received from the host device 30 or the default value as sleep time information of the slave unit to the query message and transmits it to the slave unit. Access to slave units is always performed in ascending order of slave unit addresses.

  As shown in FIG. 12, when the power is turned on (step Q1), the base unit 10 initializes the MPU of the base unit (step Q2), initializes the radio module of the base unit (Q3), Prepare a query to the child machine (Q4). Base unit 10 manages time TM for accessing the handset by its own internal timer, and transmits a query (packet) to the handset at intervals of time TM (steps Q5, Q6, Q7, Q8).

  These states are also shown in FIG. Here, base unit 10 starts the internal timer from the end of initialization operation P1 of handset # 1. Master unit 10 transmits the query to slave unit # 1 at the end of initialization operation P1 of slave unit # 1, and slave unit # 1 receives the query in reception operation P2. When the time TM1 has elapsed from the transmission of the query to the child device # 1, the parent device 10 transmits the query to the child device # 2, and when the time TM2 has elapsed from the transmission of the query to the child device # 2, When a query is transmitted to the machine # 3 and the time TM3 has elapsed from the transmission of the query to the slave unit # 3, the query is transmitted to the slave unit # 4, and the time TM4 has elapsed from the transmission of the query to the slave unit # 4 When this occurs, a query is transmitted to the slave unit # 1.

4). The radio module 470 of all the slave units is in a reception waiting state, and if the received destination address is its own station, it continues the reception operation and generates an interrupt to the control unit 430 simultaneously.
5. The control unit 430 of the slave unit wakes up from the sleep state in response to the interrupt signal INT and enters an operation state, and starts receiving a query from the wireless module 470.

  In FIG. 11A, the control unit 430 is activated from the sleep state by the interrupt signal INT (step S8). The wireless module 470 determines whether the query is addressed to the local station based on the query address. If the query is addressed to the local station, the wireless module 470 receives the query and transmits packet data of the received query to the control unit 430. Thus, reception by the control unit 430 is started (step S9).

  As shown in FIG. 10, slave units # 1 to # 4 each receive a query from the master unit, but the reception operation P2 of the slave units # 2 to # 4 has elapsed for a certain period from the initialization operation P1. When done. Also, FIG. 9A shows that the MPU wakes up when a query is received.

6). After the reception is completed, the control unit 430 of the slave unit disables the power-on signal PWRON and puts the wireless module 470 into the sleep state.
7). The control unit 430 of the slave unit calculates the sleep time Tslp based on the received state notification interval T, sets the sleep time in the sleep timer 420, and starts the timer.
8). The control unit 430 of the slave unit is woken up when the sleep time is timed out. Then, for example, when a query including a command requesting output of sensor information is received from the base unit 10, the wireless module 470 is woken up to be in a transmission state.

  In FIG. 11A, when the wireless module 470 receives a query, the control unit 430 calculates a sleep time Tslp based on the access period T included therein (step S10), and sets the sleep time Tslp in the sleep timer 420 (step S10). S11), a command ROF for setting the wireless module 470 to the sleep state is output to the wireless module 470 (step S12). The wireless module 470 shifts to a sleep state in response to the command ROF, for example, the power of the RF circuit of the wireless module is turned off and enters a low power consumption state. When in the sleep state, the wireless module 470 cannot receive a query. Note that either step S12 and steps S10 and S11 may be performed first or at the same time.

  This is shown in FIG. The slave units # 1 to # 4 set the sleep time in the sleep timer 420 in the sleep time setting operation P3, and the sleep timer 420 starts counting the sleep time Tslp from the setting time.

9. The control unit 430 of the slave unit turns on the peripheral power supply, collects information such as sensor values, input information, and slave unit type, and transmits the collected information to the master unit.
10. The control unit 430 of the slave unit turns off the peripheral power supply.
11. The control unit 430 of the slave unit sets the wireless module 470 in the power down mode (low power consumption) and turns off its own power supply.

  In FIG. 11B, the control unit 430 activates a peripheral power supply load (not shown) to execute a query function (step S13), collects information such as sensors (step S14), The part power supply load is turned off (step S15). The control unit 430 also creates a response message for transmitting the collected information to the parent device 10. Next, the control unit transmits a command RON for turning on the power of the RF circuit to the wireless module 470 (step S16), whereby the wireless module 470 is woken up and becomes ready for transmission. Next, control unit 430 transmits the packet data of the created response message to wireless module 470, and wireless module 470 transmits the response message to base unit 10 (step S17). When receiving the notification of the end of transmission of the response message from the wireless module 470, the control unit 430 turns off the power-on signal PWRON to place the wireless module 470 in the power down mode (step S18). The wireless module 470 continues the power down mode until the power on signal PWRON is turned on by the control unit 430 (step S3). As soon as the above-described series of operations is performed, the control unit 430 transmits a signal STP for stopping the DC / DC converter 402 to the power load control circuit 410, whereby the operation of the DC / DC converter 402 is stopped. (Step S19), the control part 430 will be in a power-off state (step S20). The control unit 430 is in a power-off state during the sleep time Tslp set in the sleep timer 420. When the sleep timer 420 counts the sleep time, a time over signal TMO is output to the power load control circuit 440 and responds to this. Then, the power load control circuit 440 outputs the enable signal EN to the DC / DC converter 402, the reset signal RESET2 is input to the control unit 430, internal initialization is started (step S3), and the wireless module 470 is powered on. Become a mode.

  In FIG. 9A, when the slave unit 20 starts the sleep timer and transmits a response message, the slave unit 20 is powered off, and when the sleep time Tslp elapses, the MPU is powered on and the wireless module is woken up. It is shown. In FIG. 10, the slave unit starts the sleep time Tslp timer as soon as the sleep time setting operation P3 ends, and after the response transmission operation P4 ends, the slave unit is turned off and the sleep time Tslp is set to It is shown that the power of the slave unit is turned on when the timeout occurs.

12 Master device 10 transmits information received from the slave device to host device 30. The master unit 10 performs the above processes 3 to 11 for all slave units, with (TMx = T / number of slave units n, in this example, TM1 = TM2 = TM3 = TM4) as the processing time of one slave unit. Do.
13. When the access to all the child devices is completed, the parent device inquires of the host device 30 whether there is a setting relating to the sleep time. If there is, change the sleep time settings. Specifically, the access cycle T is changed.

  The sleep times Tslp of the respective slave units are the same, but the sleep time is shifted by TM between the respective slave units. Only after the power is turned on, the slave unit continues to receive until it is accessed from the master unit.

Normal time The slave unit is in a state where only the sleep timer 420 is operating.
2. The sleep timer 420 of the slave unit generates an interrupt and turns on the power of the MPU of the slave unit when the sleep time Tslp times out.

As shown in FIG. 7, the sleep timer 420 outputs a time over signal TMO to the power load control circuit 440 at the time of timeout, and the power load control circuit 440 activates the DC / DC converter 402 in response thereto. Then, the power supply to the control unit 430 is turned on. In one preferable example, the slave unit is powered on a certain time Tp before the master unit accesses (for example, 100 ms). As described above, the sleep time Tslp is
Tslp = T-Trst-Tini-Trcv-Tst
Is calculated by
The time Tp when the slave unit is turned on before the period T when the master unit accesses is:
Tp = Trst + Tini + Trcv + Tst
It becomes.

3. When the power is turned on (Power On), the slave MPU initializes itself, sets only the wireless module 470 in an operating state, and enters the sleep state.
4). The parent device adds the status notification interval T received from the host or the default value to the slave device as a sleep time of the child device and transmits it to the child device. The slave units are always accessed in ascending order of the slave unit addresses.
5. If the wireless module 470 of the slave unit is in a reception waiting state and the received destination address is its own station, it continues the reception operation and simultaneously generates an interrupt to the MPU.
6). The MPU of the slave unit wakes up from the sleep state by the interrupt and enters an operation state, and starts receiving from the WM.
7). After completion of reception, the slave unit MPU turns off the power of the RF circuit of the wireless module 470 to enter the sleep state.
8). The MPU of the slave unit calculates the sleep time Tslp based on the received state notification interval T, sets the calculated sleep time Tslp in the sleep timer 420, and starts the timer.
9. The MPU of the slave unit turns on the power of the RF circuit of the wireless module 470 and wakes up to enter the transmission state.
10. The MPU of the slave unit turns on the peripheral power supply, collects information such as sensor values, input information, and slave unit type, and transmits the collected information to the master unit.
11. The MPU of the slave unit turns off the peripheral power supply.
12 The slave MPU puts the wireless module 470 into a power-down mode and turns off its own power supply.
13. The master unit transmits the information received from the slave unit to the host.
14 The parent device performs the above processes 3 to 11 on all the child devices with (TMx = T / number of child devices n) as the processing time of one child device.
15. When the access to all the child devices is completed, the parent device inquires of the host whether there is a setting such as a sleep time. If there is, change the settings such as sleep time.
In addition, the master unit can issue a query for inquiring the remaining battery level to the slave unit. If the master unit receives at least one battery remaining from the slave unit that is less than the threshold, The state notification cycle T is extended. The sleep times Tslp of the respective slave units are the same value, but the sleep time is shifted by TM time between the respective slave units.

11A and 11B are transition diagrams for explaining the operations of the MPU (control unit 430) and the WM (wireless module 470) of the slave unit.
S1. MPU side: When battery is powered on, reset circuit 410 outputs signal RESET1 WM side: Power on by signal PWRON S2. MPU side: The signal RESET1 is input to the power load control circuit 440, the DC / DC converter 402 is activated, and the reset circuit 412 outputs the signal RESET2. WM side: Power-down state (low power consumption)
S3. MPU side: Signal RESET2 is input to MPU, the inside of MPU is initialized, WM signal PWRON is turned on, and signal RESET3 is input to WM WM side: Transition from power-down mode to power-on mode S4. MPU side: 62 ms wait WM side: Hardware internal initialization (access from outside is impossible; 60 ms)
S5. MPU side: initialization of internal register of WM WM side: data from MPU is set in each register, completion notification S6. MPU side: Start reception monitoring timer WM side: Waiting for reception from master unit S7. MPU side: Transition to sleep state WM side: MPU interrupt occurs when receiving in the standby state of receiving from the main unit (external interrupt)
S8. MPU side: Wake-up from sleep state by interrupt from WM WM side: Reception operation S9. MPU side: reception operation WM side: reception operation and completion notification S10. MPU side; calculates sleep time Tslp from the received state notification period T WM side: operating state S11. MPU side; set sleep time Tslp to sleep timer 420 and start timer WM side; operating state S12. MPU side; puts WM in sleep state by the completion notification WM side: sleep state S13. MPU side; peripheral circuit power load (power load control circuit)
WM side; sleep state S14. MPU side; collecting information such as sensors WM side; sleep state S15. MPU side; peripheral circuit power supply no load WM side; sleep state S16. MPU side: wakes up the WM WM side: wakes up and shifts to the operating state S17. MPU side: Response packet transmission to master unit WM side: Transmission to master unit and completion notification to MPU S18. MPU side; confirms the completion notification and turns off the signal PWRON of the WM to enter the power down mode. WM side; shifts to the power down mode S19. MPU side: DC / DC converter is turned off by disenable signal DIS WM side: Power down state 20. MPU side; power down state WM side; power down state When the sleep timer 420 times out the sleep time Tslp, the signal TMO is output to the power load control circuit 420, the DC / DC converter 402 is turned on, and the process proceeds to S3.

FIG. 12 is a transition diagram for explaining the operations of the MPU (control unit) and the WM (wireless module) of the master unit.
Q1. Power on Q2. MPU internal initialization Q3. Initialization of WM internal register from MPU Q4. Packet preparation for the first slave unit (address; # 01) Q5. Real timer start with TM value TM = T / number of slave units n (processing time per slave unit)
Q6. Send packet to slave unit Q7. Wait for reception from the slave unit after transmission is completed.
When TM = time out, step S8 (no response from slave unit)
Q8. Prepare the next slave unit packet ⇒ Go to step S5 Q9. Send the received packet from the slave unit to the host. Completion in other than the final slave unit ⇒ Go to step S10 Complete in the final slave unit ⇒ Go to step Q11 Packet preparation for the next slave unit ⇒ Go to step Q12 Q11. Request information from host Receive information from host ⇒ Go to step Q10 Q12. TM time-out waiting time-out ⇒ go to step Q5

  It should be noted here that when the number of connected slave units is n, even if one or a plurality of slave units are in a tooth-missing state (non-connected state), the master unit has a predetermined order ( For example, all n child devices are accessed in ascending order of address). Even if there is a slave unit that has lost teeth, there is no response from the slave unit, and the period T for accessing all the slave units does not change. Synchronization with the wake-up period is maintained.

  FIG. 13 is a diagram illustrating an overall configuration of a wireless communication sensor system according to an embodiment of the present invention. The wireless communication sensor system 1 shown in FIG. 1 directly connects the parent device 10 and the child device 20 wirelessly, but mediates wireless communication between the parent device 10 and the child device 20 as shown in FIG. A configuration including the repeater 40 may be used. Thereby, although it does not change in function from the wireless communication sensor system 1 shown in FIG. 1, it is possible to configure the system even when the parent device 10 and the child device 20 are so far away that direct wireless communication is not possible. Become.

  In the above embodiment, the slave unit receives the access cycle T or the sleep information from the master unit, and the slave unit itself calculates the sleep time Tslp and sets it to the timer. It is also possible to transmit the sleep time Tslp to all the slave units, and the slave unit can set the sleep time Tslp.

The wireless communication sensor system according to the embodiment of the present invention has the following effects.
・ Battery drive can be realized through two-way communication between the master and slave units.
-Since two-way communication is possible between the master unit and the slave unit, information can be set and changed on the slave unit while the system is online.
-The master unit calculates the sleep time of the slave unit and sends it to the slave unit every time it issues a query, and the slave unit uses it as a sleep timer. Guaranteed.
-Since the query from the master unit to the slave units is performed for all the slave units every time, the sleep time can be set for the slave units participating in the system on the way. The same applies to the case where the slave unit is turned off, temporarily disconnected from the system, and then turned on again to participate in the system.
-By providing a slave unit type in the entire communication protocol and registering that type in the system in advance, it becomes possible to plug and play the slave unit.
The method according to the present embodiment is not affected even if there is a repeater between the master unit and the slave unit, because access from the master unit is only delayed by the processing time of the repeater.

  Next, a second embodiment of the present invention will be described. This embodiment relates to synchronization correction between a parent device and a child device. If errors accumulate in the synchronization between the parent device and the child device due to changes over time or other factors, the synchronization between the parent device and the child device will eventually shift, and good data communication cannot be performed. In the second embodiment, when a synchronization shift occurs between the parent device and the child device, the synchronization is corrected.

  FIG. 14 is a diagram showing a functional configuration of a communication control program according to the second embodiment of the present invention. The communication control program 200A of the present embodiment includes a synchronization correction unit 260 that corrects synchronization between the parent device and the child device in addition to the configuration shown in FIG. The synchronization correction unit 260 corrects the synchronization between the parent device and the child device when a synchronization shift between the parent device and the child device is detected. As shown in FIG. 14B, the synchronization correction unit 260 includes a synchronization deviation determination unit 262 and a cycle time / number of times calculation unit 264.

  A small error occurs in the timer of the master unit and the timer of the slave unit due to factors such as the operating environment of the device (especially temperature) and the remaining battery level. Synchronization is lost, especially when the slave unit sleeps for a long time. Then, when the child device is accessed from the parent device, a situation occurs in which the child device is not waked up. In other words, a situation may occur in which the slave unit wakes up after the master unit accesses the slave unit, and the slave unit continues to wait for access from the master unit.

The synchronization deviation determination unit 262 , when unable to receive a response message within a period expected to receive a response message from the slave unit, is not synchronized with the slave unit, that is, the synchronization deviation. Is determined.

  When the synchronization deviation determination unit 262 determines that the synchronization correction is necessary, the cycle time / number calculation unit 264 calculates the sleep time and the number of times for performing the synchronization correction of the target child device. Specifically, the cycle time / number-of-times calculation unit 264 calculates the sleep time for synchronization correction obtained by dividing the sleep time of the slave unit in any way without changing the access cycle T of the master unit. For example, when the sleep time of the slave unit is 10 minutes, 1 minute is calculated as the sleep time for synchronization correction, and 10 is calculated as the number of times. That is, the sleep time for synchronization correction × number of times is calculated to be equal to or substantially equal to the sleep time of the slave unit.

When the synchronization deviation determination unit 262 determines that the synchronization correction of the slave unit is necessary, the query creation unit 210 displays the device address of the target slave unit, the function code Fd as shown in FIG. A query having correction data regarding the sleep time / number of times for synchronization correction is created, and the query transmission unit 230 transmits the created query to the target child device. The function code Fd is a command for causing the slave unit to set the sleep time and the number of times for synchronization correction.

  FIG. 15 shows a flow of the synchronization correction sequence of the master unit. The synchronization correction unit 260 of the parent device accesses the plurality of child devices at the access cycle T and checks whether or not a response message from each child device has been received within a certain period (S100). If the synchronization correction unit 260 cannot receive the response message within the period, the synchronization correction unit 260 determines that synchronization correction with the child device is necessary because the synchronization with the child device is lost ( S102). Next, the cycle time / number of times calculation unit 264 calculates the sleep time for synchronization correction and the number of times (S104), and the query creation unit 210 sets the correction data regarding the sleep time / number of times for synchronization correction, the function code Fd, Is created and transmitted to the corresponding slave unit (S106). The slave unit performs synchronization correction based on the correction data (S108), and upon receiving the synchronization end from the slave unit, the synchronization correction unit 260 ends the synchronization correction of the slave unit (S110).

  FIG. 16 shows the configuration of the main circuit of the slave unit according to the second embodiment. The main circuit of the slave unit of the second embodiment is obtained by adding a counter 480 to the main circuit of the first embodiment shown in FIG. 7, and the other configuration is substantially the same. FIG. 17 shows a functional configuration of the control unit 430 according to the second embodiment. The functional configuration of the control unit 430 of the second embodiment is obtained by adding a synchronization correction execution unit 570 to the configuration of the first embodiment shown in FIG. 8, and other configurations are substantially the same. It is.

The synchronization correction execution unit 570 sets the sleep time and the number of times for synchronization correction included in the correction data in the sleep timer 420 and the counter 480 according to the function code Fd included in the query received from the parent device. Specifically, the slave unit calculates the sleep time Tslp for synchronization correction according to the following formula, similarly to the case of the first embodiment, and sets the calculated sleep time Tslp in the sleep timer 420.
Tslp = T-Trst-Tini-Trcv-Tst
(Trst is the reset time inside the slave unit, Tini is the initialization time inside the slave unit, Trcv is the transmission time of the master unit + the reception time of the slave unit, and Tst is the time until the sleep timer setting and timer start).

  As in the first embodiment, the control unit 430 is powered off during the sleep time Tslp, and is powered on when the sleep timer 420 times out. When the control unit 430 is powered on, the synchronization correction execution unit 570 decrements the value of the counter 480 (decreases by “−1”). When there is an access from the parent device, the synchronization correction execution unit 570 refers to the value of the counter 480, and if the count value is not “1” or “0”, it stops creating and sending a response message to the parent device When the count value is “1”, a synchronization completion response message is generated and transmitted to the parent device. When the count value becomes “0”, the synchronization correction operation by the synchronization correction execution unit 570 is not performed, and the normal operation is performed.

  FIG. 18A is a timing chart when the parent device and the child device are synchronized, and FIG. 18B is a timing chart when the parent device and the child device are not synchronized. If synchronization is established, at time t1, the slave unit times up and wakes up. Time Tp (Tp = Trst + Tini + Trcv + Tst) is between time t1 and time t2. Access Tac_1 of the parent device is performed within a certain time Tg from time t2 to time t3. The fixed time Tg is a time during which the synchronization between the parent device and the child device can be allowed. When the parent device Tac_1 is performed within the time Tg, the child device receives a query from the parent device and transmits a response message to the query, and then enters a sleep state.

  On the other hand, when the synchronization between the parent device and the child device is lost, as shown in FIG. 18B, when there is an access Tac_1 from the parent device, the child device is still in the sleep state. Therefore, a query from the parent device is not received by the child device, and a response message from the child device is not returned to the parent device. Thereafter, the slave unit wakes up at time t3, and the slave unit continues to wait for access from the master unit. When there is the next access Tac_2 of the parent device, the child device transmits a response message to the query from the parent device.

  FIG. 18C is a timing chart for explaining the synchronization correction according to the present embodiment. Here, the number of slave units is 16, and the synchronization of the 16th slave unit is corrected. The sleep time for synchronization correction is a time obtained by dividing the sleep time of the slave unit into 16 equal parts, and the number of times is 16. Further, the access cycle Tac of the parent device for the 16th child device is shorter than the interval of the sleep time for synchronization correction, and C1, C2, C3 to C16 are timings when there is an access from the parent device.

Operation C1: The sleep timer 420 of the slave unit generates an interrupt when the value of the sleep time Tslp times out, turns on the MPU of the slave unit, and corrects data (sleep time, number of times) from the master unit Receive a query that contains. Since the detailed operation of the slave unit is the same as that in the first embodiment, the description thereof is omitted.
The slave unit calculates the actual sleep time Tslp based on the correction data, sets the sleep time in the sleep timer 420, stores the number of times in the counter 480, and starts the timer.
Tslp = T-Trst-Tini-Trcv-Tst
This is the time during which internal processing is performed and the reception wait state is entered before the parent device accesses.
-The slave unit transmits a response packet to the master unit.
・ The handset is turned off.

C2 to C14: The slave timer 420 of the slave unit generates an interrupt when the sleep time Tslp times out, turns on the MPU of the slave unit, and waits for access from the master unit.
The slave unit checks whether the counter 480 is “0” or “1” at the time of access from the master unit. Since the number of times is neither “0” nor “1”, the counter 480 is set to “−1” and saved, and at the same time, the sleep timer 420 is started.
・ Since the number of times is not “0” or “1”, the slave unit does not send a response message to the master unit, recognizes only that the master unit has accessed, and immediately turns off. .

C15: The sleep timer 420 of the slave unit generates an interrupt when the sleep time Tslp has timed out, turns on the MPU of the slave unit, and waits for access from the master unit.
Since the counter 480 is “1” at the time of access from the parent device, the child device transmits a synchronization end response message to the parent device.
The slave unit sends a synchronization end response message to the master unit, then sets the counter 480 to “−1” and enters a power-off state.

C16: The slave timer 420 of the slave unit generates an interrupt when the sleep time Tslp times out, turns on the MPU of the slave unit, and waits for access from the master unit.
The slave unit checks whether or not the counter 480 is “0” at the time of access from the master unit. Since the count value is “0”, a query from the parent device is received and normal operation is performed.
The slave unit performs the following calculation based on the received status notification interval (T), calculates the sleep time Tslp, sets the sleep time in the sleep timer 420, and starts the timer. Next, if there is a synchronization correction instruction from the parent device, the counter 480 is set again with the number of times, otherwise the count value remains “0”.
Tslp = T-Trst-Tini-Trcv-Tst
This is the time during which internal processing is performed and the reception wait state is entered before the parent device accesses.
-The slave unit sends a response message to the master unit.
・ The handset is turned off.

  The slave unit repeats sleep / wake-up repeatedly with a sleep time for synchronization correction shorter than the sleep time (processing of C2 to C15), thereby correcting the synchronization with the master unit. In addition, by matching the sleep time and number of times for synchronization correction with the sleep time, the parent device can automatically perform synchronization correction of the slave device that is out of synchronization without changing the sleep cycle time. .

Furthermore, according to the present embodiment, it is possible to set and operate different sleep timer values for each slave unit.
By performing the sleep cycle synchronization correction between the master unit and the slave unit, the sleep timer time can be set indefinitely.
The battery life can be extended by extending the sleep timer time from a certain remaining battery level and ambient temperature.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment, and various modifications can be made within the scope of the present invention described in the claims. Deformation / change is possible.

1: wireless communication sensor system 10: parent device 20 (20a to 20n): child device 30: host device 200: communication control program 210: query creation unit 220: sleep time information setting unit 230: query transmission unit 240: response message reception Unit 250: handset information providing unit 400: battery 402, 404: DC / DC converter 410, 412: reset circuit 420: sleep timer 430: control unit (MPU) 440: power load control circuit 450: address holding unit 460: Interrupt control unit 470: wireless module 480: counter

Claims (6)

A wireless communication system including a plurality of slave units driven by a battery and a master unit that performs wireless communication with the plurality of slave units,
The master unit transmits a query including sleep time information regarding the sleep time of the slave unit to all the slave units at a determined access cycle TM,
Receiving means for receiving a response message to the query;
Determining means for determining whether or not the slave is out of synchronization based on the reception status of the response message;
Correction means for transmitting to the transmission means a query including a correction instruction for correcting synchronization and sleep time information for synchronization correction obtained by dividing the sleep time of the slave unit into a plurality when the synchronization time is determined to be out of sync; Have
Each of the plurality of slave units
A receiving means for receiving a query from the parent device;
A sleep setting means for setting the sleep time based on the sleep time information included in the received query and measuring the sleep time;
Power control means for turning off the power of the main circuit when setting the sleep time and turning on the power of the main circuit when the sleep time elapses;
A transmission means for transmitting a response message to the query from the master unit;
When a query including the sleep time information for synchronization correction and the correction command is received, the sleep setting unit is configured to set a sleep time based on the sleep time information for synchronization correction according to the correction command, and a plurality of sleeps Synchronization correction execution means for repeating wake-up ,
A wireless communication system in which a time when a parent device accesses each of a plurality of child devices is synchronized with a sleep time of the child devices. The wireless communication system according to claim 1 , wherein the sleep time set based on the sleep time information for synchronization correction × the set number of times is equal to the sleep time of one slave unit. The wireless communication system according to claim 1 or 2, wherein the master unit performs synchronization correction of the slave unit without changing the access cycle TM to the slave unit. The access cycle TM is T / n when the access cycle T for accessing all the slave units and the number n of slave units are set, and the master unit accesses the slave units at a time interval of the access cycle TM. The wireless communication system according to any one of 1 to 3. A wireless communication method in a wireless communication system including a plurality of slave units driven by a battery and a master unit that performs wireless communication with the plurality of slave units,
The master unit transmits a query including sleep time information related to the sleep time of the slave unit to all the slave units at a determined access cycle TM;
Determining whether or not the slave is out of synchronization based on the reception status of the response message;
A step of causing the transmission means to transmit a query including a correction time for correcting the synchronization and the sleep time information for synchronization correction obtained by dividing the sleep time of the slave unit into a plurality when the synchronization is determined to be out of sync. Have
Each of the plurality of slave units receives a query transmitted from the master unit;
Setting the sleep time in the sleep timer based on the sleep time information included in the received query and starting the sleep timer;
Sending a response message to the query;
After sending the response message, turning off the main circuit during the sleep time and turning on the main circuit when the sleep time elapses;
When a query including the sleep time information for synchronization correction and the correction command is received, the sleep setting unit is configured to set a sleep time based on the sleep time information for synchronization correction according to the correction command, and a plurality of sleeps And repeating the wake-up ,
A wireless communication method in which a time when a parent device accesses each of a plurality of child devices is synchronized with a sleep time of the child device. The sleep time set based on the sleep time information for synchronization correction × the set number of times is equal to the sleep time of one slave unit, and the master unit changes the access cycle T for accessing all slave units. The wireless communication method according to claim 5, wherein the slave unit is corrected for synchronization.

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