JP2009130567A - Unidirectional radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a unidirectional radio communication system wherein cross talk is prevented at a low cost and signals from a plurality of transmitters are surely received by a receiver even when a communication channel is switched. <P>SOLUTION: When there are the plurality of transmitters 1 for the receiver 2, frequency switching requests from the respective transmitters 1 are received by the frequency of the communication channel before the request on the side of the receiver 2, and the frequency of the communication channel is switched from the frequency before the frequency switching request to the other frequency same as the respective transmitters 1 and fixed on the side of the receiver 2 for the first time at the point of time of completing frequency switching on the side of all the transmitters 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a unidirectional wireless communication system that is applied when various loads are remotely controlled by wireless signals.

  For example, when remotely operating a large number of lighting fixtures installed in a building or the like, a transmitter is provided on a wall surface or the like, a receiver is provided on a lighting fixture attached to a ceiling or the like, and a radio signal from the transmitter is received. By transmitting to the receiver, the lighting device is turned on or off.

  In such a communication system, a plurality of transmitters transmit signals at the frequency of the same communication channel for transportation, but when various electronic devices are installed in the building, interference with other signals is caused. An environment is likely to occur. In this way, when interference with other signals occurs, the desired remote operation cannot be performed smoothly. Therefore, it is different from frequencies that are likely to cause interference among the frequencies of a plurality of communication channels assigned in advance. It is necessary to switch to the frequency of the communication channel.

  In this case, if the system switches the frequency of not only the transmitter but also the receiver individually by switch operation, as in the above example, for many receivers installed at high places such as the ceiling, stepladders, etc. It is necessary to provide a scaffolding to perform the switching operation, which is very time-consuming and dangerous.

  As a countermeasure, it is conceivable to apply a so-called MCA radio technology that automatically selects and uses a frequency of an empty channel from a plurality of communication channel frequencies. However, in this case, since the transmitter and the receiver need to perform bidirectional communication for frequency switching control of each communication channel, the system is complicated, and transmission and reception are respectively performed for the transmitter and the receiver. There is a problem that it is necessary to provide a circuit and it becomes expensive. In order to prevent interference, it may be possible to adopt a frequency popping method or a direct spreading method as a spread spectrum technique. In this case, however, the system becomes complicated and expensive.

Therefore, in the prior art, when remote-controlling various devices wirelessly, in order to prevent interference at low cost, specific identification information unique to the receiving side is added to an information signal to be transmitted and a predetermined communication channel is set. Transmitting means for repeatedly transmitting at a frequency, and receiving means for sequentially switching the frequency of the communication channel until receiving identification information unique to the receiving side is received, and fixing to the frequency of the received communication channel when the unique identification information is received A unidirectional wireless communication system is proposed in which when the unique identification information on the transmitting side and the receiving side matches, the receiving side is fixed to one of the frequencies of the plurality of communication channels. (For example, refer to Patent Document 1 below).
Japanese Patent No. 4-22292

  By the way, if the transmitter and the receiver are each a single unit and the two correspond to each other, there is no problem even if the technique of Patent Document 1 is adopted. However, in practice, it may be necessary to transmit signals from a plurality of transmitters to one receiver. For example, in the case of remotely operating a lighting fixture installed in a building such as the above-mentioned building, when the floor area of the building is large, considering the convenience when remotely operating the lighting fixture, In some cases, a plurality of transmitters are dispersedly arranged at locations apart from each other with respect to the built-in receiver, and a control signal is transmitted from each transmitter to control the blinking of the luminaire.

  As described above, when a plurality of transmitters coexist with one receiver, the identification information transmitted by adding to the information signal from a certain transmitter is transmitted to the receiver side as in the above-mentioned Patent Document 1. If the communication channel is immediately fixed to one frequency on the receiver side when it matches the unique identification information, the transmission frequencies of the other remaining transmitters are not yet switched. Even if the control signal is transmitted, it is not received by the receiver, and there is a problem that the lighting apparatus cannot be blinked.

  In addition, when multiple people operate the transmitter independently, it may not be possible to recognize that the frequency of the communication channel of the receiver has already been switched, and the operator has failed the transmitter or receiver. There is a risk of making judgments on its own, which is unusable.

  The present invention has been made to solve the above-described problem. When a plurality of transmitters exist for one receiver, the present invention aims to prevent interference at low cost and to switch each communication channel even when switching communication channels. To provide a unidirectional wireless communication system that ensures that a signal from a transmitter is received by a receiver, and that an operator of each transmitter can reliably recognize a frequency switching state of a communication channel. With the goal.

  In order to achieve the above object, the present invention adopts the following configuration in a unidirectional wireless communication system having a plurality of transmitters for wireless transmission and a receiver for receiving a wireless signal from each transmitter. is doing.

  That is, in the first aspect of the present invention, the transmitter includes a frequency switching request generating unit that generates a frequency switching request for a communication channel, and a frequency switching request generated by the frequency switching request generating unit. Pre-transmission means for adding identification information and transmitting to the transmitter at the frequency before the frequency switching request, and transmission for switching the communication channel from the frequency before the frequency switching request to another frequency after signal transmission by this pre-transmission means A frequency switching unit, on the basis of the identification information registration unit in which unique identification information of a transmitter to be received is registered in advance, and the identification information added to the frequency switching request. It is determined whether or not a frequency switching request is output from all transmitters registered in the identification information registration means, and frequency switching is performed from all transmitters. It determined that when being output is characterized by comprising a receiving frequency switching means for switching to the transmitter with another of the same frequency from the frequency before frequency switching request frequency communication channels, a.

  According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the receiver is externally informed that there is a frequency switching request in response to reception of the frequency switching request transmitted from the transmitter. The reception frequency switching means stops the operation of the notification means in response to frequency switching of the communication channel.

  According to the first aspect of the present invention, when there are a plurality of transmitters for the receiver, the receiver side accepts the frequency switching request from each transmitter with the frequency of the communication channel before the request, Because the frequency of the communication channel is switched and fixed from the frequency before the frequency switching request to the other frequency same as each transmitter for the first time at the time when the frequency switching is completed on the transmitter side of Thus, it is possible to prevent interference at low cost, and even when the frequency is switched, the transmission signal from each transmitter is reliably received by the receiver. For this reason, it is possible to reliably prevent problems such as inability to remotely control the load of the lighting fixture or the like.

  According to the second aspect of the invention, until the frequency switching is completed in all of the transmitter and the receiver, the notification means of the receiver informs the outside that the frequency switching is incomplete, and the communication channel Since the notification operation by the notification means stops only when all frequency switching is completed, the operator of each transmitter arbitrarily determines that the transmitter or receiver has failed at the stage where frequency switching has not been completed. This can eliminate the risk of being lost and improve usability.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram of a unidirectional wireless communication system according to an embodiment of the present invention. The unidirectional wireless communication system of this embodiment has a plurality of transmitters 1 for wireless transmission and receivers 2 that receive radio signals from the respective transmitters 1. A load 3 is connected. For example, when the lighting fixture is remotely operated as the load 3, each transmitter 1 is dispersedly arranged on the indoor wall surface of the building and the receiver 2 is placed inside the lighting fixture arranged on the ceiling or the like. Arranged.

  The transmitter 1 includes a control command generation unit 11 that generates various control commands for the load 3 (for example, control commands such as blinking and dimming when the load 3 is a lighting fixture), and a frequency of the communication channel. A frequency switching request unit 12 that generates a switching request; an ID storage unit 13 that stores a unique ID number assigned to the transmitter 1; an RF modulation unit 14 that modulates transmission data into an RF signal; The ID stored in the ID storage unit 13 for the transmission antenna unit 15 that wirelessly transmits the RF signal and the load control command generated by the control command generation unit 11 and the frequency switching request generated by the frequency switching request unit 12 A transmission control unit 16 that adds a number to generate transmission data and controls the RF modulation unit 14 in response to a frequency switching request from the frequency switching request unit 12 is provided.

  It should be noted that the frequency switching request unit 12 is a frequency switching request generation unit in the claims, and the RF modulation unit 14 and the transmission control unit 16 are pre-transmission units in the claims. Corresponds to the transmission frequency switching means in the claims.

  On the other hand, the receiver 2 includes a receiving antenna unit 21 that receives an RF signal transmitted from the transmitter 1 wirelessly, an RF demodulating unit 22 that demodulates the RF signal, and a receiver 2 that is a reception target. An ID input unit 23 for setting and registering an ID number in advance; an ID storage unit 24 for storing the ID number input from the ID input unit 23 and storing the reception status of the frequency switching request from the transmitter 1; In response to the frequency switching request from the transmitter 1, the notifying unit 25 that informs the outside that there is a frequency switching request, and the RF demodulating unit 22, the load 3, and the notifying unit 25 based on the transmission signal from the transmitter 1. And a reception control unit 26 for controlling each of them. Note that the notification unit 25 can be applied without any particular limitation as long as the operator of the transmitter 1 can recognize the notification state of the receiver 2 from the outside, such as a buzzer or a lamp. The ID storage unit 24 is the identification information registration unit in the claims, the notification unit 25 is the notification unit in the claims, and the reception control unit 26 is the reception frequency switching in the claims. It corresponds to each means.

  Next, the operation of the unidirectional wireless communication system having the above configuration will be described with reference to FIG. 2 and FIG. Here, as an example, as shown in FIG. 2, transmitters 1a and 1b and receivers 2a and 2b are installed at two locations in a building, and a load 3 (for example, , Lighting fixtures) are connected. In addition, one receiver 2a is at a distance at which radio signals from both transmitters 1a and 1b can be received together, but the other receiver 2b is separated from one transmitter 1a and thus the other transmitter 1b. It is assumed that it is in a state where only a radio signal from can be received. Therefore, although the ID numbers of both transmitters 1a and 1b are registered in advance in the ID storage unit 24 of one receiver 2a, the other transmitter 1b is stored in the ID storage unit 24 of the other receiver 2b. Only the ID number is registered in advance.

(1) Operation when controlling the load 3 with the frequency A of the preset communication channel As shown in FIG. 2A, at the present time, the communication channel of each transmitter 1a, 1b is set as the frequency A, It is assumed that the communication channel of each of the receivers 2a and 2b is also set to the frequency A.

  Here, when controlling the load 3 connected to one receiver 2a, for example, when the control command generation unit 11 of one transmitter 1a is operated to generate a load control command, the transmission control unit 16 As shown in 3 (a), the ID number stored in the ID storage unit 13 is added to this load control command to create transmission data.

  Subsequently, the RF modulation unit 14 modulates the transmission data into an RF signal having the frequency A under the control of the transmission control unit 16. And since this RF signal is wirelessly transmitted from the transmission antenna part 15, this transmission signal is received by one receiver 2a.

  When the receiving antenna unit 21 receives the RF signal having the frequency A, the receiver 2 sends this signal to the RF demodulating unit 22 at the next stage. Therefore, the RF demodulating unit 22 demodulates the RF signal into received data. . Next, the reception control unit 26 determines whether or not the ID number included in the demodulated reception data is already registered in the ID storage unit 24. If the ID number is registered, the load included in the reception data is subsequently determined. The load 3 is controlled based on the control command. For this reason, when the load 3 is a lighting fixture, blinking and dimming control are performed by this load control command.

  Further, since the radio signal transmitted from the other transmitter 1b is received by the two receivers 2a and 2b, when the load control command is output from the other transmitter 1b, the above control is performed. As in the case of operation, the load 3 connected to each receiver 2a, 2b is controlled simultaneously.

(2) Operation when switching the frequency of the communication channel When there is a need to switch the frequency because there is a possibility of interference at the frequency A of the communication channel set at the present time, for example, one transmitter 1a The frequency switching request unit 12 is operated.

  Then, since the frequency switching request is given from the frequency switching request unit 12 to the transmission control unit 16, in response to this, the transmission control unit 16 assigns an ID number to the frequency switching request as shown in FIG. Create the added transmission data. Then, the transmission data is repeated a plurality of times and output to the RF modulation unit 14. At that time, the transmission control unit 16 does not immediately change the communication channel, but controls the RF modulation unit 14 to modulate the transmission data with the frequency A of the original communication channel.

  Thus, the transmission data is modulated into an RF signal having the frequency A by the RF modulation unit 14, and the RF signal is wirelessly transmitted from the transmission antenna unit 15 a plurality of times. Then, after repeatedly transmitting this signal, the transmission control unit 16 switches the frequency of the communication channel when the transmission data is modulated by the RF modulation unit 14 from the frequency A to the frequency B.

  On the other hand, when the RF signal of frequency A is received by the receiving antenna unit 21, the receiver 2a sends this signal to the RF demodulating unit 22 at the next stage, so that the RF demodulating unit 22 converts this RF signal into received data. Demodulate.

  Next, the reception control unit 26 determines whether or not the ID number included in the demodulated reception data is already registered in the ID storage unit 24. If the ID number is not registered, the received data is ignored. On the other hand, if the ID number is registered, the reception control unit 26 determines whether or not a frequency switching request is included in the demodulated reception data. At this time, if a frequency switching request is included in the received data, the reception status of the current frequency switching request from each transmitter 1a, 1b is checked with reference to the ID storage unit 24.

  That is, the reception control unit 26 receives, for example, a frequency switching request at a location corresponding to the ID number of the transmitter 1a registered in the ID storage unit 24 in response to the reception of the frequency switching request transmitted from the transmitter 1a. The flag “1” indicating “completed” is set, and it is checked whether or not all the received frequency switching request flags corresponding to the ID numbers of the transmitters 1 a and 1 b are “1”.

  At this time, if the received frequency switching request flags corresponding to the ID numbers of the transmitters 1a and 1b are not all “1”, no frequency switching request has been output from all the transmitters 1a and 1b. Therefore, as shown in FIG. 2B, the reception control unit 26 activates the notification unit 25 to notify the outside that there is a frequency switching request by flashing light or the like.

  While the notification unit 25 is operating, it is possible to recognize that the frequency switching of the transmitters 1a and 1b and the receiver 2a has not been completed by looking at the notification operation. Therefore, when the frequency switching request unit 12 of the other transmitter 1b is operated, the transmission data in which the ID number is added to the frequency switching request is transmitted from the other transmitter 1b to the frequency before the frequency switching, as described above. It is modulated into an RF signal having A and is repeatedly transmitted from the transmitting antenna unit 15 a plurality of times. After repeatedly transmitting this signal, the transmission control unit 16 switches the frequency of the communication channel from the frequency A to the frequency B thereafter.

  Here, when the RF signal of the frequency A from the other transmitter 1b is received by the receiving antenna unit 21 of the one receiver 2a, the RF demodulating unit 22 demodulates the RF signal into transmission data. The unit 26 determines whether or not the ID number included in the demodulated reception data is already registered in the ID storage unit. If the ID number is registered, the frequency is switched to the demodulated reception data. Determine whether the request is included. When the received data includes a frequency switching request, the reception control unit 26 refers to the ID storage unit 24 and checks the reception status of the current frequency switching request from each transmitter 1. That is, it is checked whether or not all the flags for which the frequency switching request has been received from each transmitter 1 are “1”.

  When a frequency switching request is issued from both transmitters 1a and 1b, all of the frequency switching request received flags corresponding to the ID numbers of the transmitters 1a and 1b are all “1” in the ID storage unit 24. Therefore, for the first time at this time, the reception control unit 26 switches the frequency of the communication channel from the frequency A to the frequency B as shown in FIG. And the reception control part 26 stops the alerting | reporting operation | movement of the alerting | reporting part 25 simultaneously with the frequency switching of this communication channel.

  In addition, when transmission data in which an ID number is added to a frequency switching request from the other transmitter 1b is modulated into an RF signal of frequency A and repeatedly transmitted over the radio, the RF signal of frequency A is transmitted to the other receiver. 2b is also received simultaneously.

  At this time, since only one ID number corresponding to the other transmitter 1b is registered in the ID storage unit 24 of the other receiver 2b, all the frequency switching request received flags in the ID storage unit 24 are “1”. The reception control unit 26 immediately switches the frequency of the communication channel from the frequency A to the frequency B. Therefore, the notification operation of the notification unit 25 is not performed.

  After the communication channels of the transmitters 1a and 1b and the receivers 2a and 2b are all switched to the frequency B in this way, the load from any one of the transmitters 1a or 1b is the same as in the case (1). The load 3 is remotely operated by a radio signal of frequency B including a control command.

  As described above, in this embodiment, when there are a plurality of transmitters 1a and 1b for one receiver, for example, 2a, the frequency switching request signal from each transmitter 1a and 1b is received on the receiver 2a side. It is accepted with the frequency A of the communication channel before the frequency switching, and the frequency of the communication channel on the receiver 2a side is the same as that of each transmitter 1a, 1b only when the frequency switching is completed on all the transmitters 1a, 1b side. The frequency B is switched to be fixed.

  For this reason, interference prevention can be realized at low cost by unidirectional communication, and transmission signals from the transmitters 1a and 1b are reliably received by the receivers 2a and 2b even when the frequency is switched. It becomes like this. Thereby, it is possible to reliably prevent problems such as the remote operation of the load 3 such as a lighting fixture.

  Further, on the receiver 2a side, the notification unit 25 notifies the outside that the frequency switching is not completed until the frequency switching is completed, and the notification unit is the first time when the frequency switching of the communication channel is completed on the receiver 2a side. Since the notification operation by the transmitter 25 is stopped, the operator of each transmitter 1 may recognize that the frequency switching between the transmitter 1 and the receiver 2 has not yet been completed while the notification unit 25 is operating. it can. As a result, the operator can eliminate the possibility that the transmitter 1a, 1b or the receiver 2a will be determined to have failed at the stage where the frequency switching has not been completed, thereby improving usability.

  In the example shown in FIG. 2, the case where two transmitters and two receivers are installed has been described. However, the present invention is not limited to this, and a plurality of receivers are provided for one receiver. The present invention can be widely applied to a unidirectional wireless communication system in which a transmitter is installed.

  In this embodiment, two communication channels, frequency A and frequency B, are alternately switched. However, it is also possible to sequentially switch to three or more frequencies.

It is a block diagram of the unidirectional radio | wireless communications system in embodiment of this invention. It is explanatory drawing for demonstrating operation | movement of the system. It is explanatory drawing which shows typically the content of the packet transmitted by radio | wireless by the system.

Explanation of symbols

1, 1A, 1B Transmitter 2, 2A, 2B Receiver 3 Load 11 Control command generation unit 12 Frequency switching request unit (frequency switching request generation means)
14 RF modulator (pre-transmission means)
16 Transmission control unit (prior transmission means, transmission frequency switching means)
22 RF demodulator 24 ID storage (identification information registration means)
25 Notification part (notification means)
26 Reception Control Unit (Reception Frequency Switching Means)

Claims (2)

A unidirectional wireless communication system having a plurality of transmitters for wireless transmission and a receiver for receiving a wireless signal from each transmitter,
Each transmitter includes a frequency switching request generating unit that generates a frequency switching request for a communication channel, and a frequency switching request by adding identification information unique to the transmitter to the frequency switching request generated by the frequency switching request generating unit. A pre-transmission means for transmitting to the transmitter with the previous frequency, and a transmission frequency switching means for switching the communication channel from the frequency before the frequency switch request to another frequency after signal transmission by the pre-transmission means,
The receiver is registered in the identification information registration means based on the identification information registration means in which unique identification information of the transmitter to be received is registered in advance and the identification information added to the frequency switching request. It is determined whether or not a frequency switching request is output from all transmitters, and when the frequency switching request is output from all transmitters, the frequency of the communication channel is changed from the frequency before the frequency switching request to the transmitter. And a reception frequency switching means for switching to the same other frequency.   The receiver has notification means for notifying the outside that there is a frequency switching request in response to reception of the frequency switching request transmitted from the transmitter, and the reception frequency switching means includes a frequency of a communication channel. The unidirectional wireless communication system according to claim 1, wherein the operation of the notification means is stopped in response to switching.

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