JPH09247762A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system whose power consumption is reduced. SOLUTION: The system has a master set 10 having at least a reception section and one slave set 12 or over having at least a transmission section and in communication enable with the master set 10, each slave set 12 is provided with a timer section and the time of each timer section is set identically. Furthermore, a permissible time denoting a common communication enable time range is set in advance in each timer section and the transmission section of each slave set 12 is at a pause usually and started only when the time of the timer section is within a permissible time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system, and more particularly to a communication system that is composed of a master unit and one or more slave units and can reduce power consumption.

[0002]

2. Description of the Related Art A general communication system including a master unit 10 and one or more slave units 12 (consisting of n units, where n is a natural number) will be described with reference to FIG. First, the basic configuration will be described. The main unit 10 and each of the slave units 12 have a reception unit (not shown), a transmission unit (not shown), and a control unit (not shown) that controls the reception unit and the transmission unit.
Data communication is possible via Each slave 12 is installed for each external device 16 (consisting of the same number n as slaves 12), and has a function of sending data measured by the external device 16 to the master 10. A plurality of external devices 16 may be connected to each child device 12. In this case, each slave unit 12 has a configuration in which the data measured by the plurality of external devices 16 are sequentially fetched and the data are sent to the master unit 10. Furthermore, each slave unit 12 is provided with a timer unit (not shown), and the control unit of each slave unit 12 controls the reception unit and the transmission unit based on the time of the timer unit, and performs the operation of fetching data from an external device. .

The transmission line 14 may be an optical cable or a metal cable. Further, in recent years, an automatic meter reading system for automatically metering a fluid such as water or gas has been put into practical use, and various communication systems for transmitting meter reading data and the like are used therein. In this case, each of the slaves 12 is installed in a flow meter that performs fluid meter reading as the external device 16, and sends meter reading data measured by each flow meter to the transmission path 14. The applicant of the present application also discloses a communication system used in an automatic meter reading system.
As described in 5-252578, we have applied for a communication system that uses sound waves as a medium and outputs the sound waves to a conduit such as a water pipe or a gas pipe to perform data communication. It becomes a pipeline such as a pipe or a gas pipe. In some cases, the transmission unit and the reception unit have a wireless transmission / reception function, and data communication is performed without using the transmission path 14 as described above.

Next, a conventional operation of the communication system having the above configuration will be described. Each slave unit 12 is normally in a dormant state, but when the receiver unit is activated via the control unit at each time interval preset in the timer unit for each slave unit 12 and becomes the activated state. The control unit detects the presence or absence of the call signal from the base unit 10 via the receiving unit, and if the call signal is received, the control unit continues the activated state and stores the measurement data of the external device 16 ( Note that this measurement data may be fetched from the external device 16 thereafter) is sent to the transmission path 14 via the sending unit. When the transmission of the measurement data is completed, the sleep state is entered again. Here, the hibernate state means a state in which power is not supplied to the receiving unit and the transmitting unit, and only the timer unit and the control unit are in the operating state. In addition, the activation state refers to a case where the reception unit and the transmission unit are also activated. in this way,
Each cordless handset 12 is normally hibernated, but each cordless handset 1
By adopting a method in which the timer is started at each preset time interval in the timer unit for each 2 to communicate with the base unit 10,
It is possible to reduce the power consumption as compared with the case where the system is always activated. It should be noted that the master unit 10 keeps the receiving unit and the transmitting unit in a constantly activated state, and the control unit sequentially calls each of the slave units 12 via the receiving unit and the transmitting unit, and the slave unit 12 in the communicable state starts from the external unit. 16 measurement data are captured and processed.

[0005]

However, the above conventional communication system has the following problems. Since each slave unit repeatedly starts and sleeps asynchronously with each other, in order to perform data communication with the master unit, it is necessary to increase the probability of detecting a call signal sent asynchronously from the master unit. Therefore, it is necessary to frequently activate the receiving unit with large power consumption, and there is a problem that the power consumption on the slave side increases. In particular, in the case of a child device, in many cases, it is configured to be driven by a battery in order to easily attach it to an external device, and an increase in power consumption leads to a decrease in operating time and a shortened product life. There are challenges. Also, even if the battery is replaceable,
There is also a problem that the replacement work cost increases because the battery replacement cycle becomes short. If the replacement cycle is made to be as long as possible, the capacity of the battery must be increased, which raises a problem of increasing the component cost, that is, the product cost. In addition, since each slave unit is asynchronously activated in the master unit side as well, it is necessary to keep the slave unit in the active state at all times, which also increases power consumption. Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a communication system capable of reducing power consumption.

[0006]

In order to solve the above problems, the present invention has the following constitution. That is, there is provided a communication system comprising one master unit having at least a receiving unit and one or more slave units having at least a transmitting unit and capable of communicating with the master unit, each slave unit having a timer unit. Is provided, the time of each timer unit is set to be the same, and an allowable time indicating a common communication allowable time range is preset in each timer unit, and the transmitter of the slave unit is normally in a dormant state. The timer is activated only when the time of the timer unit is within the allowable time. If this configuration is adopted, the slaves are activated at the same time within a predetermined allowable time, so that the master can determine that all the slaves are in the activated state when detecting the signal transmitted from the slaves. . Therefore, it is not necessary to detect whether or not each child device is in the activated state for all the child devices, and it is not necessary for the child device side to be frequently activated as well, reducing the power consumption of the child device. It becomes possible to do. As a result, the time required for the master unit to communicate with all the slave units can be shortened, and efficient data communication with the slave units becomes possible.

Further, the master unit is provided with a transmission unit and a timer unit, the slave unit is provided with a reception unit, and the timer unit of the slave unit has a time of the timer unit of the master unit within the allowable time. Based on the above, if the time is adjusted at the same time,
The base unit can also be activated within the same allowable time as the handset, and can normally be put into a dormant state, and power consumption on the base unit side can be reduced. In addition, each time the slave unit communicates with the master unit, each timer is adjusted to the same time, so even if it is used for a long time, the time between the master unit and each slave unit does not significantly deviate from each other. Data communication becomes possible.

Further, when the master unit is provided with a transmitting unit and is connected to a host device having a timer unit via the receiving unit, the slave unit is provided with the receiving unit and the slave unit is provided. The timer unit may be configured to adjust the time to the same time based on the time of the timer unit of the host device via the master unit within the allowable time.

Further, specifically, the slave unit has a built-in battery, and the transmitter unit of the slave unit is supplied with power from the battery only when the time of the timer unit is within the allowable time. It may be configured to be.

[0010]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The configuration of the communication system of the present embodiment, that is, the relationship between the master unit, the slave unit, and the external device is similar to the basic configuration of the communication system of FIG. 1 described in the conventional example. In the present embodiment, an automatic meter reading system for water supply is described as an example, but an automatic meter reading system for gas (combustible gas such as propane gas and city gas) may be used.

First, the basic structure of each slave unit 12 will be described with reference to FIG. The basic configuration of each slave unit 12 is the same. Reference numeral 18 denotes a transmission / reception unit, which is connected to the transmission path 14 with the base unit 10 and sends out transmission data from the control unit, which will be described later, to the transmission path 14 and fetches received data from the transmission path 14. Note that, as described above, the wireless transmission / reception function may be provided to perform the data communication without using the transmission path 14. Reference numeral 20 denotes a timer unit, which is configured by using, for example, a timer IC and has a function of generating time data. Further, a memory (not shown) is provided inside, and an allowable time indicating a common communication allowable time range is stored in advance in the memory. Also,
The timer unit 20 also has a function of turning on / off a switch described later. A control unit 22 includes a microprocessor (hereinafter, MPU) 24, a main memory 26, and an input / output interface (also referred to as an I / O port) 28. An operation program that defines the operation of the MPU 24 is stored in the main memory 26 in advance.

Various sensors 30 and meters 32 inside the external device 16 are connected to the input / output interface 28,
The detection signal of the sensor 30 and the measurement data measured by the meter 32 can be taken in. The captured data is MPU
24 is input. A battery 34 supplies electric power to the transmitting / receiving unit 18, the timer unit 20, and the control unit 22. The battery 34 is detachably attached to the cordless handset 12 and can be replaced. Although the present embodiment is configured to also supply power to the external device 16 to which the slave device 12 is connected, this is not necessary when the external device 16 itself is configured to be supplied with power from the outside. is there.

A switch 36 is a component other than the battery 34 and the timer unit 20 (control unit 22, transmission / reception unit 18).
And external device 16, and input / output interface 28
May be included). The switch 36 is on / off controlled by the timer unit 20. Basically, the master device 10 basically has a configuration similar to that of the slave device 12, and a transmission / reception unit (not shown), a timer unit (not shown), and a control unit (not shown) connected to the transmission line 14 are basically required. ), And a power supply unit (not shown) that supplies power to each of these components. The power supply unit may be a general commercially available power supply that converts a commercial AC voltage into a DC voltage, or the battery 34 may be used as in the slave unit 12.

Next, the operation of the communication system will be described with reference to FIGS.
This will be described with reference to FIG. First, when the parent device 10 and the child device 12 start to operate, the timer units 20 of the parent device 10 and the child device 12 turn on the switch 36. This gives M
Electric power is supplied to the PU 24 from the battery 34, and the MPU 2
4 initializes the timer unit 20, the transmitting / receiving unit 18, the main memory 26, etc. (step 100 in FIG. 3, step 200 in FIG. 4). Subsequently, the MPU of the master device 10 starts the operation of the timer unit and outputs the time data indicated by the current timer unit to the transmission path via the transmission / reception unit (step 102 in FIG. 3). After step 200, each child device 12 is in a state of waiting for input of time data from the parent device 10 (step 202 in FIG. 4), and when the input of time data is detected, the internal devices are internally operated based on the time data. Timer part 2
The time is set to 0 (step 204 in FIG. 4). As a result, the timer units 20 of the parent device 10 and all the child devices 12 operate at the same time.

A timer unit 20 inside the master unit 10 and all the slave units 12
Turns off the switch 36 after a lapse of a predetermined time, and puts the parent device 10 and all the child devices 12 in a dormant state (step 104 in FIG. 3, step 206 in FIG. 4). In the sleep state, the power supply from the battery 34 to the transmission / reception unit 18, the control unit 22, and the external device 16 is stopped, so that the power consumption can be reduced. After that, the timer units 20 inside the master unit 10 and all the slave units 12 check whether or not the current time reaches a common allowable time stored in advance in the internal memory of the timer unit 20 while ticking the same time. (Fig. 3
106, step 208 of FIG. 4). Then, when the timer unit 20 detects that the time has reached the first allowable time (time T1 in FIG. 5), the timer unit 20 turns on the switch 36 to turn on the transmission / reception unit 18, the control unit 22, and the external device 16. The supply of electric power from the battery 34 is started, and the master device 10 and all slave devices 12 are activated (step 1 in FIG. 3).
08, step 210 in FIG. 4).

[0016] When activated, the MPU of each slave unit 12
24 captures measurement data and the like from the external device 16 via the input / output interface 28 and sends it to the transmission path 14 via the transmission / reception unit 18 (step 212 in FIG. 4). Since the parent device 10 is also activated at the same time, measurement data and the like from each child device 12 sent from the transmission line 14 can be taken in (step 110 in FIG. 3). When the acquisition of the measurement data into the master device 10 is completed, the master device 10 returns to step 102, and the slave device 12 returns to step 202.
The time of the timer unit 20 on the slave unit 12 side is adjusted again. In this way, by adjusting the time each time the master device 10 and the slave device 12 perform data communication, it is possible to always match the timings at which the master device 10 and the slave device 12 are activated.

As described above, the master unit 10 repeats Step 102 to Step 110, and each slave unit 12 repeats Step 202 to Step 212, so that each preset allowable time (time T1 to T2, T3-T4 ...
.), The parent device 10 and the child device 12 are in the activated state and perform data communication with each other, and the other devices are both in the dormant state. Therefore, the child device 12 and further the parent device 1 are compared to the configuration of the conventional example.
It is possible to reduce the power consumption of 0. Further, although the respective slaves 12 are activated at substantially the same time, the master 10 has identification data of each slave 12 included in the data sent from each slave 12 (different frequencies for modulating the data are used. May be present), and communication is sequentially started from the child device 12 that has received the data. The slave 12 that has completed the communication waits for input of time data from the master 10 (step 2 in FIG. 4).
02). In addition, each child device 12 repeatedly transmits data until communication with the parent device 10 is performed, but the length of the allowable time is long enough for all the child devices 12 to communicate with the parent device 10. It is set.

It is to be noted that all the above-described master unit 10 and slave unit 12 are regarded as slave units, and, for example, an artificial satellite is used as the master unit, so that the timers 20 of the above-mentioned master unit 10 and slave unit 12 are set in time. You may do it. In addition, the base unit 10 is further illustrated in FIG.
When connected to the higher-level device 40 having a built-in timer unit as indicated by the dotted line in FIG. It may be performed by transmitting it to the child device 12 via the device 10. Further, the timer unit 20 may be provided only in the slave unit 12 that is often driven by the battery 34. Even with this configuration, since the slaves 12 are simultaneously activated in a predetermined allowable time, when the master 10 detects a signal transmitted from the slaves 12, it determines that all the slaves 12 are active. it can. Therefore, it is not necessary to detect whether or not each of the slaves 12 is in the activated state for all the slaves 12, and it is not necessary to frequently activate the slaves 12 side. It is possible to reduce power consumption.

Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and time adjustment is performed at each allowable time,
It may be performed every several times. Further, instead of the transmission / reception unit, a transmission unit and a reception unit may be provided. In addition, even if the parent device and the child device are configured not to use the battery, it is inevitable that the power consumption can be reduced, and the electricity bill can be reduced, etc. within a range not departing from the spirit of the invention. Of course, it is possible to make modifications.

[0020]

In the communication system according to the present invention, since the slave unit having the timer unit is simultaneously activated in a predetermined allowable time, when the master unit detects a signal transmitted from the slave unit, all of the slave units are activated. It is possible to judge that the slave units are in the activated state, it is not necessary to detect whether or not each slave unit is in the activated state for all the slave units, and the slave units do not need to be frequently activated. Therefore, the power consumption of the child device can be reduced. As a result, the time required for the master unit to communicate with all the slave units can be shortened, and efficient data communication with the slave units becomes possible. Furthermore, if the master unit is also provided with a timer unit and the timer unit of the slave unit is configured to adjust the time to the same time based on the time of the timer unit of the master unit within the allowable time, the master unit also becomes the slave unit. It is possible to start the system in the same permissible time and normally set it to the dormant state, and it is possible to reduce the power consumption on the base unit side, so that the power consumption of the entire communication system can be further reduced. In addition, each time the slave unit communicates with the master unit, each timer is adjusted to the same time, so even if it is used for a long time, the time between the master unit and each slave unit does not significantly deviate from each other. The remarkable effect that various data communication becomes possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a communication system including a master unit and a slave unit.

FIG. 2 is a block diagram showing a configuration of a child device of the communication system according to the present invention.

FIG. 3 is a flowchart showing the operation of the master unit of the communication system according to the present invention.

FIG. 4 is a flowchart showing the operation of the child device of FIG.

FIG. 5 is a timing chart showing an allowable time (which is also a switch on time) set in a timer unit of a master unit and a slave unit of a communication system according to the present invention.

[Explanation of symbols]

 10 Master Unit 12 Slave Unit 18 Transmitter / Receiver Unit 20 Timer Unit 22 Control Unit 34 Battery

Claims (4)

[Claims] 1. A communication system comprising: one master unit having at least a receiving unit; and one or more slave units having at least a transmitting unit and capable of communicating with the master unit. Each timer unit is provided, the time of each timer unit is set to the same, and an allowable time indicating a common communication allowable time range is preset in each timer unit, and the transmitter unit of the slave unit is normally stopped. A communication system which is in a state and is activated only when the time of the timer unit is within the allowable time. 2. The master unit is provided with a transmitting unit and a timer unit, the slave unit is provided with a receiving unit, and the timer unit of the slave unit has a timer unit of the master unit within the allowable time. The communication system according to claim 1, wherein the time is adjusted to the same time based on the time. 3. The transmission unit is provided in the master unit, and is connected to a host device having a timer unit via the reception unit, the reception unit is provided in the slave unit, and the timer unit of the slave unit is , Based on the time of the timer unit of the host device via the master unit within the allowable time,
The communication system according to claim 1, wherein the time is adjusted at the same time. 4. A battery is built in the slave unit, and the transmitter of the slave unit is supplied with power from the battery only when the time of the timer unit is within the allowable time. The communication system according to claim 1, 2 or 3.