JP2002101004A - Communication system and method for setting frequency - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a communication system which receives RF signals transmitted from a transmission-side terminal by means of a reception-side terminal, to easily and surely switch and set the frequency of the RF signals. SOLUTION: When a remote control system 1 selects a frequency on a remote controller side 2, an RF-transmitting section 22 continuously transmits an RF signal (RF check code) for confirmation to a receiver 3 by using the selected frequency over a prescribed period of time. While the RF signal is being transmitted, the receiver 3 receives the RF signal (<; RF CHECK CODE>;) by successively switching receiving channels and, upon receiving the confirming RF signal (<; RF CHECK CODE>), it sets the frequency of the receiving channel as a received frequency. Thereafter, the receiver receives the RF signals by using the received frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a communication system and a frequency setting method, and more particularly, to a frequency setting of an RF signal in a communication system in which a receiving terminal receives an RF signal transmitted from a transmitting terminal. .

[0002]

2. Description of the Related Art As a communication system for receiving an RF signal from a transmitting terminal at a receiving terminal, for example, an electronic device or the like that receives a remote control signal transmitted from an RF remote controller and operates in accordance with the remote control signal There is a remote control system. In this type of remote control system, since a general-purpose frequency band is used for an RF signal, when there are a plurality of RF devices in the vicinity, the frequency bands used by these RF devices may overlap. For this reason, the RF signal may interfere, and the electronic device may malfunction or the electronic device may not be used.

In order to avoid malfunctions of electronic devices due to such RF signal interference, electronic devices and remote controllers include:
A frequency changeover switch for switching to another frequency is provided. Then, both the frequencies of the remote controller and the electronic device are set manually by the user. Hereinafter, a conventional frequency setting method will be described with reference to FIG.

When setting the frequency on the remote controller side, FIG.
As shown in (A), when the mode key provided on the remote controller is operated to set the RF frequency setting mode (step A101), the transmission frequency or channel of the RF signal currently set on the display unit of the remote controller is changed. It is displayed (step A102). Furthermore, when a desired frequency is selected by operating the frequency change key (step A10)
3) The selected frequencies are sequentially displayed on the display unit (step A104), and the currently displayed frequency is set in the RF transmission unit as the transmission frequency by operating the enter key (step A105). Thereafter, the remote controller transmits the RF signal at the set transmission frequency (step A10).
6).

When setting the frequency of an electronic device (receiver), as shown in FIG. 5B, a mode key provided on the receiver body is operated to set an RF frequency setting mode (step B101). ), The reception frequency or channel of the RF signal that is currently set is displayed on the display section of the receiver body (step B102). Further, when a desired frequency is selected by operating the frequency change key (step B103), the selected frequencies are sequentially displayed on the display unit (step B104), and the currently displayed frequency is received by operating the enter key. The frequency is set (step B105). Thereafter, the receiver waits for reception of the RF signal at the set reception frequency (step B106).

[0006]

As described above, when switching the frequency in the conventional communication system, the frequency has been set manually by the user for both the transmitting terminal and the receiving terminal. For this reason, there is a possibility that an operation error or a frequency setting error may occur. In addition, it is necessary for the user to repeatedly perform the same frequency setting operation on the transmitting terminal and the receiving terminal, which is troublesome.

An object of the present invention is to make it possible to easily and reliably switch and set the frequency of an RF signal in a communication system in which a receiving terminal receives an RF signal transmitted from a transmitting terminal.

[0008]

In order to achieve the above object, according to the present invention, a transmitting terminal for transmitting an RF signal (for example, a remote controller 2 shown in FIG. 1) and a transmitting terminal for transmitting the RF signal are provided. In a communication system (for example, the remote control system 1 shown in FIG. 1) configured with a receiving terminal (for example, the receiver 3 shown in FIG. 1) that receives a signal transmitted from the terminal, the transmitting terminal is an RF Selection means for selecting the signal transmission frequency (for example, the control unit 2 shown in FIG. 1)
1. Frequency change key 24a) and transmission means (for example, control unit 21 and RF transmission unit 22 shown in FIG. 1) for transmitting the confirmation RF signal at the transmission frequency selected by the selection means for a predetermined time. A receiving unit (for example, the control unit 31 and the remote control PLL circuit 32 shown in FIG. 1) for receiving the confirmation RF signal transmitted from the transmitting terminal while sequentially switching a reception frequency; Setting means (for example, the control unit 31 shown in FIG. 1) for setting a frequency of which reception has been accepted by the receiving means as a reception frequency.
And a reception frequency data memory 313b) shown in FIG.

According to the communication system of the first aspect of the present invention, the selecting means and the transmitting means of the transmitting-side terminal provide:
When the confirmation RF signal is transmitted to the receiving terminal at the selected transmission frequency, the received confirmation RF signal is received by the receiving means and the setting means of the receiving terminal while sequentially switching the reception frequency, and is received. The frequency is set in the receiving terminal as the receiving frequency.

According to a fifth aspect of the present invention, there is provided a frequency setting method in a communication system comprising a transmitting terminal for transmitting an RF signal and a receiving terminal for receiving a signal transmitted from the transmitting terminal. Then, the transmitting side terminal selects a transmission frequency of the RF signal (for example, A1 to A5 shown in FIG. 4A), and uses the transmission frequency selected in the selection step to check the RF signal for confirmation. Is transmitted for a predetermined time (for example, A11 shown in FIG. 4A).
To A12), wherein the receiving terminal receives the confirmation RF signal transmitted from the transmitting terminal while sequentially switching the receiving frequency (for example, FIG. 4B).
B5 to B9), and a setting step of setting a frequency at which reception has been received in the reception step as a reception frequency (for example, B10 shown in FIG. 4B).

According to the fifth aspect of the present invention, when the confirmation RF signal is transmitted to the receiving terminal at the selected transmitting frequency in the transmitting terminal selecting step and the transmitting step, the receiving terminal performs the receiving step. In the setting step, the transmitted confirmation RF signal is received while sequentially switching the reception frequency, and the received frequency is set in the reception-side terminal as the reception frequency.

Therefore, according to the first and fifth aspects of the present invention, the user can automatically set the frequency of the receiving terminal by switching the frequency at the transmitting terminal, and can easily set the frequency of the RF signal. Switching settings can be made reliably.

According to a second aspect of the present invention, in the communication system according to the first aspect, the transmitting unit transmits the start RF signal at all transmittable frequencies and then transmits the start RF signal. Signal transmission is started (for example, FIG. 4
(A6 to A10 shown in (A)), after receiving the start RF signal transmitted from the transmitting terminal,
The reception of the confirmation RF signal is started in synchronization with the transmission start timing of the confirmation RF signal (for example, FIG.
B1 to B4) shown in (B) are effective.

According to a sixth aspect of the present invention, in the frequency setting method according to the fifth aspect, in the transmitting step, after transmitting the start RF signals at all transmittable frequencies, the start-up RF signal is transmitted. After starting the transmission of the RF signal and receiving the start RF signal transmitted from the transmitting terminal in the receiving step, receiving the confirmation RF signal in synchronization with the transmission start timing of the confirmation RF signal It is effective to start.

According to the second and sixth aspects of the present invention, the transmitting terminal transmits the start RF signal at all transmittable frequencies, and then starts transmitting the confirmation RF signal. The terminal is a starting RF transmitted from the transmitting terminal.
After receiving the signal, the reception of the confirmation RF signal is started in synchronization with the transmission start timing of the confirmation RF signal, so that the receiving terminal can reliably recognize the start of the frequency setting operation, and at a reliable timing. A frequency setting operation can be performed.

In the communication system according to the first aspect of the present invention, the transmitting terminal may include:
It is effective to further include a transmission end output unit (for example, the display unit 23 shown in FIG. 1) that outputs a message indicating that the transmission has been completed after the transmission unit has finished transmitting the confirmation RF signal.

According to the third aspect of the present invention, the transmission end output means can confirm that the transmission of the confirmation RF signal has been completed.

Further, as in the invention according to claim 4, in the communication system according to claim 1, the receiving terminal includes:
It is effective to further include a setting result output unit (for example, the display unit 34 shown in FIG. 1) for outputting a setting result of the reception frequency by the setting unit.

According to the fourth aspect of the present invention, the set reception frequency and the success or failure of the set frequency can be confirmed by the setting result output means.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a communication system and a frequency setting method according to the present invention will be described in detail with reference to the drawings.

First, the configuration will be described. FIG. 1 is a system configuration diagram of a remote control system 1 which is an example of a communication system according to the present invention. As shown in FIG. 1, a remote control system 1 transmits an RF signal to an electronic device (a receiving terminal; hereinafter, referred to as a receiver 3) including a receiving unit that receives an RF signal from the outside. It is configured by a remote controller 2 (transmitting terminal).

The remote controller 2 includes an RF transmitting section 22 for transmitting an RF signal for remotely controlling the receiver 3, a display section 23 for performing various displays, and an input section 24 for inputting various instructions.
And a control unit 21 for controlling these units.

FIG. 2 is a block diagram showing the internal configuration of the control unit 21 of the remote controller 2. As shown in FIG.
1 is a CPU (Central Processing Unit) 211, R
OM (Read Only Memory) 212, RAM (Random Acc
ess Memory) 213 and I / O (Input / Output) 21
4 and the like.

The CPU 211 stores a control program corresponding to the remote controller 2 stored in the ROM 212, an input instruction or input data from the input unit 24 in a work memory in the RAM 213, and in accordance with the input instruction and the input data, the RAM 213. The operation of the remote controller 2 is controlled according to the control program stored therein.

Also, the CPU 211 responds to the input instruction
A frequency setting process described later (see FIG. 4A) is executed. In the frequency setting process, the CPU 211
Of the transmission frequency of the RF signal from the RAM 213, and stores the selected frequency in the selected frequency data memory 21 of the RAM 213.
3a. Further, a start RF signal <AUTO TUNNING STARTCODE>, which is a signal for causing the receiver to recognize the start of the auto tuning operation, is sequentially transmitted to the receiver 3 at all transmittable frequencies (for example, three channels). Thereafter, the RF signal for confirmation <RF CHECK CODE> is continuously transmitted for a predetermined time at the selected frequency stored in the RAM 213. Here, the transmission time of the confirmation RF signal <RFCHECK CODE> is a time from the start of the auto tuning operation on the receiver 3 side to the end thereof. When the transmission of the check RF signal <RF CHECK CODE> ends, the CPU 211
Displays on the display unit 23 that the transmission has been completed.

The ROM 212 stores a control program, data, and the like corresponding to the remote controller 2. Note that R
The control program stored in the OM 212 includes a frequency setting processing program, and the data stored in the ROM 212 includes frequency data of a plurality of channels.

The RAM 213 is set in a work memory for storing programs, input instructions, and input data input from the CPU 211, a selected frequency data memory 213a for storing frequency data selected by the user, and the RF transmitter 22. It has a transmission frequency data memory 213b for storing transmission frequency data.

The RF transmitting section 22 includes a power amplifier, a frequency converter, a frequency synthesizer, and the like, and transmits an RF signal at a predetermined transmission frequency to the receiver 3 according to a control signal input from the control section 21. For example,
The start RF signal <AUTO TUNNING START CODE> is transmitted at all switchable channel frequencies, and the check RF signal <RF CHECK CODE> is transmitted at a frequency selected by a user operation. After setting the frequency, the RF signal is transmitted at the set transmission frequency.

The display unit 23 includes a liquid crystal display, an LED,
(Light Emitting Diode), FL, etc., and displays various display data according to a display control signal input from the control unit 21.

The input unit 24 includes a frequency change key 24a, a decision key 24b, and other operation keys, and outputs a key press signal to the CPU 211. The frequency change key 24a is a key operated when selecting a frequency (channel), and the confirm key 24b is a key operated when confirming the selection of the frequency.

Next, referring to FIG. 1 and FIG.
Will be described. As shown in FIG. 1, the receiver 3
Control unit (microcomputer) 31, remote control PLL (Phase-Lo)
cked Loop) circuit 32, remote control code demodulation circuit 33,
And a display unit 34.

FIG. 3 is a block diagram showing the internal configuration of the control unit 31 of the receiver 3. As shown in FIG. 3, the control unit 31 is configured by a microcomputer including a CPU 311, a ROM 312, a RAM 313, an I / O 314, and the like.

The CPU 311 converts a control program specified from various control programs corresponding to the receiver 3 stored in the ROM 312, an input instruction from an input unit (not shown), and an RF signal input from the remote controller 2 into RA.
The operation of the receiver 3 is controlled in accordance with the control program stored in the RAM 313 in accordance with the input instruction and the input data stored in the work memory in the M 313.

The CPU 311 executes a frequency setting process described later (see FIG. 4B). In this frequency setting process, the CPU 311 controls the remote controller PLL circuit 32
RF signal sequentially transmitted from remote controller 2 to <AUTO
TUNNING START CODE> at the frequency of any one of the channels, and the remote control PLL circuit 32
When the reception detection signal of the signal <AUTO TUNNING START CODE> is input, the confirmation RF signal <RF CHEC
The auto tuning operation starts in synchronization with the transmission start timing of K CODE>. In the auto tuning operation,
The CPU 311 sequentially changes the reception frequency (channel) of the remote control PLL circuit 32 while checking the confirmation RF signal <RF
CHECK CODE> is received, the received frequency is stored as a reception frequency in the reception frequency data memory 313b of the RAM 313, and the setting result of the reception frequency is displayed on the display unit 34. Thereafter, the remote control PLL circuit 32 waits for reception of the RF signal at this reception frequency.

The ROM 312 stores various control programs and data corresponding to the receiver 3. In addition,
The control program stored in the ROM 312 includes a frequency setting processing program, and the data stored in the ROM 312 includes frequency data of a plurality of channels.

The RAM 313 has a reception standby timer 313a and a reception frequency data memory 313b in addition to a work memory for storing programs, input instructions, and input data input from the CPU 311.

The reception standby timer 313a synchronizes the transmission start timing of the confirmation RF signal <RF CHECK CODE> on the remote controller 2 with the start timing of the auto tuning operation on the receiver 3 side, so that the start RF signal <AUTO TUNNIN
A timer for setting a predetermined standby time after receiving G START CODE>. The waiting time is, for example, for starting during reception.
What is necessary is just to calculate from the order of the frequency channel of RF signal <AUTO TUNNING START CODE>.

The reception frequency data memory 313b stores reception frequency data set by the auto tuning operation.

The remote control PLL circuit 32 has an external R
A receiving circuit that receives the F signal, and when the antenna 32a detects the RF signal, the receiving circuit sends the received detection signal to the control unit 3
1 and outputs the received RF signal to the remote control code demodulation circuit 33.

The remote control code demodulation circuit 33 demodulates the RF signal input from the remote control PLL circuit 32 into a remote control code corresponding to the receiver 3 and outputs the demodulated signal to the control unit 31.

The display unit 34 is a liquid crystal display, LE
D, FL, and the like, and displays various display data according to a display control signal input from the control unit 31.

Next, the operation will be described with reference to FIG. FIG.
5A is a flowchart illustrating a frequency setting operation in the remote control system 1, and FIG. 5A illustrates processing on the remote control 2 side, and FIG. 4B illustrates processing on the receiver 3 side. In the following description, the switchable frequency channels in the remote control system 1 are three bands.

First, when the RF frequency setting mode is set by the operation keys provided on the input section 24 of the remote controller 2 (step A1), the CPU 211 causes the CPU 211 to set the RF currently set on the display section 23 of the remote controller 2. Display the signal transmission frequency or channel (step A
2). Further, when the frequency change key 24a is operated to select a desired frequency (or channel) (step A3), the CPU 211 sequentially displays the selected frequencies on the display unit 23 (step A4), and presses the enter key 24b. The selected frequency data memory 213a of the RAM 213 uses the frequency currently displayed by the operation as the selected frequency data.
(Step A5).

Next, the CPU 211 sets the channel to “ch”.
1 "(step A6), and the frequency of the set channel" ch1 "is set in the RF transmitting section 22 (step A7), and the start RF signal <AUTO TUNN is transmitted to the receiver 3.
ING START CODE> is transmitted (step A8). Next, the CPU 211 sets the channel of the RF transmission unit 22 to “c”.
h2 ”(step A9 → step A10; N
o), returning to step A7, and setting the channel “ch”
The frequency “2” is set in the RF transmission unit 22 and the start RF signal <AUTO TUNNING START CODE> is transmitted to the receiver 3. In this way, the channels are sequentially switched, and the start RF signal <AUTO TUNNING START CODE> is transmitted to the receiver 3 at the frequencies of all the channels (here, up to “ch3”).

On the other hand, the receiver 3
Waiting for signal reception. At this stage, the reception frequency on the receiver 3 side is arbitrary, and does not have to match the transmission frequency of the remote controller 2.

The CPU 311 of the receiver 3 has a remote control P
When the reception detection signal is input from the LL circuit 32 (step B1; Yes), the received RF signal is changed to the start RF signal.
Determine whether it is <AUTO TUNNING START CODE>.
Here, since the start RF signal <AUTOTUNNING START CODE> is sequentially transmitted at the frequencies of all the channels, the receiver 3 outputs the start RF signal <AUTOTUNNING START CODE> at any frequency.
ING START CODE> can be received.

Start RF signal <AUTO TUNNING START CODE
> (Step B2; Yes), the remote control 2 side confirmation R
A standby time for synchronizing with the transmission start timing of the F signal <RF CHECK CODE> is calculated, and the reception standby timer 313a
(Step B3), and waits. When the set standby time has elapsed (Step B4; Yes), the automatic tuning operation (Step B5 to Step B10) is started.

The remote controller 2 executes the processing of steps A7 to A10 to start RF signal <AUT at the frequency of each channel.
After transmitting O TUNNING START CODE> to the receiver 3 (step A10; Yes), the selected frequency stored in the selected frequency data memory 213a of the RAM 213 is changed to RF.
The setting is made in the transmitting section 22 (step A11), and the RF signal for confirmation <RF CHECK CODE> is continuously transmitted at the selected frequency for a predetermined time (step A12). Transmission time is receiver 3
Is the time from the start of the auto tuning operation to the end thereof.

On the other hand, the receiver 3 starts the auto tuning operation in synchronization with the transmission start timing of the confirmation RF signal <RF CHECK CODE> on the remote controller 2 side. First, the channel of the remote control PLL circuit 32 is set to "ch1" (step B5), and the frequency of the set channel "ch1" is set to the remote control PLL circuit 32 (step B).
6), RF for confirmation from remote controller 2 at this reception frequency
It is determined whether or not a signal <RF CHECK CODE> has been received (step B7). If the confirmation RF signal <RF CHECK CODE> has not been received and the frequency has not been switched to “ch3” (Step B7; No → Step B8; No), the channel is incremented by “+1” (Step B9). The frequency of the channel is set in the remote control PLL circuit 32, and it is determined again whether or not the confirmation RF signal <RF CHECK CODE> from the remote control 2 has been received at this reception frequency. Such an operation is repeated up to the channel "ch3", and when the check RF signal <RF CHECK CODE> is received at any frequency (step B7; Yes), the frequency of the received channel is used as the reception frequency data in the RAM 313. It is stored in the reception frequency data memory 313b (step B10) and displayed on the display unit 34 (step B).
11). Thereafter, at this reception frequency, R
An F signal is received.

In the auto tuning operation,
RF check signal <RF CHECK CODE on any channel
> Is not received (Step B7; No → B
8; Yes), the frequency set before the start of the auto tuning operation is set in the remote control PLL circuit 32 (step B12), and the check RF signal <RF CHECK CODE>
Is displayed on the display unit 34 (step B13), and the process ends.

In the remote controller 2, the confirmation RF signal <RF until the auto tuning operation in the receiver 3 is completed.
After transmitting the CHECK CODE>, a message indicating that the transmission has been completed is displayed on the display unit 23 (step A13).

As described above, according to the remote control system 1 of the present embodiment, when a frequency is selected on the remote controller 2, the confirmation RF signal <RF CHEC
K CODE> is continuously transmitted to the receiver 3 for a predetermined time. During this time, the receiver 3 receives the confirmation RF signal <RF CHECK CODE> while sequentially switching the reception channel,
When the check RF signal <RF CHECK CODE> is received, the frequency of the reception channel is set as the reception frequency in the RAM 31.
3 and thereafter receive the RF signal at this reception frequency.

Therefore, if the frequency is selected on the remote controller 2 side, the reception frequency on the receiver 3 side is also automatically set, so that setting mistakes and the like by manual operation can be eliminated, and the frequency switching setting operation can be easily performed. Becomes

Before starting the auto-tuning operation, the remote controller 2 sends a start RF signal to the receiver 3.
The signal <AUTO TUNNING START CODE> is transmitted at all channel frequencies, and the receiver 3 receives the start RF signal <AUTO TUNNING START CODE> at any frequency. Can be recognized. Furthermore, since the receiver 3 starts the auto-tuning operation in synchronization with the transmission start timing of the confirmation RF signal <RF CHECK CODE>, the auto-tuning operation can be performed reliably.

After the end of the auto tuning operation,
Since the set receiving frequency is output to the display unit 34 of the receiver 3, the user can easily confirm the set receiving frequency. Since the remote control 2 also outputs the end of the auto tuning operation to the display unit 23, the user can easily confirm the end of the auto tuning operation.

In the above-described embodiment, the remote controller 2
Has been described as the transmitting terminal, and the electronic device (receiver 3) is described as the receiving terminal. For example, when the electronic device 3 and the remote controller 2 have a bidirectional RF transmission / reception function, the frequency selected by the electronic device 3 is
May be automatically set on the remote controller 2 by the auto tuning operation on the side.

The scope of the present invention includes electronic devices such as audio devices and TVs, remote control systems such as remote controllers for remotely controlling these devices, and transceivers for transmitting and receiving RF signals bidirectionally. Any communication system may be included as long as an RF signal transmitted from one terminal can be received by the other terminal. In addition, the frequency selection operation method, the number of channels, and the like are arbitrary, and it is needless to say that they can be appropriately changed without departing from the spirit of the present invention.

[0058]

According to the communication system of the first and fifth aspects of the present invention, the user can automatically set the frequency of the receiving terminal by performing the frequency switching operation at the transmitting terminal.
The frequency of the signal can be easily and reliably switched.

According to the second and sixth aspects of the present invention, the transmitting terminal transmits the start RF signal at all transmittable frequencies, and then starts transmitting the confirmation RF signal. The terminal is a starting RF transmitted from the transmitting terminal.
After receiving the signal, the reception of the confirmation RF signal is started in synchronization with the transmission start timing of the confirmation RF signal, so that the receiving terminal can reliably recognize the start of the frequency setting operation, and at a reliable timing. A frequency setting operation can be performed.

According to the third aspect of the present invention, the transmission completion output means can confirm that the transmission of the confirmation RF signal has been completed.

According to the fourth aspect of the present invention, the set reception frequency and the success or failure of the set frequency can be confirmed by the setting result output means.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a remote control system 1 according to the present invention.

FIG. 2 is a block diagram showing an internal configuration of a control unit 21 of the remote controller 2.

FIG. 3 is a block diagram showing an internal configuration of a control unit 31 of the receiver 3.

FIGS. 4A and 4B are flowcharts for explaining a frequency setting operation in the remote control system 1. FIG. 4A shows processing on the remote controller 2 side, and FIG. 4B shows processing on the receiver 3 side.

FIG. 5 is a flowchart illustrating a frequency setting method in a conventional communication system, where (A) shows processing on the remote controller side and (B) shows processing on the receiver side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Remote control system 2 Remote control 21 Control part 211 CPU 212 ROM 213 RAM 213a Selection frequency data memory 213b Transmission frequency data memory 214 I / O 22 RF transmission part 23 Display part 24 Input part 3 Receiver 31 Control part 311 CPU 312 ROM 313 RAM 313a Reception standby timer 313b Reception frequency data memory 314 I / O 32 Remote control PLL circuit 33 Remote control code demodulation circuit 34 Display unit

Claims (6)

[Claims] 1. A communication system comprising a transmitting terminal for transmitting an RF signal and a receiving terminal for receiving a signal transmitted from the transmitting terminal, wherein the transmitting terminal has a transmission frequency of the RF signal. And a confirmation R at the transmission frequency selected by the selection means.
Transmitting means for transmitting an F signal for a predetermined time, wherein the receiving terminal receives the confirmation RF signal transmitted from the transmitting terminal while sequentially switching a receiving frequency; and Setting means for setting a frequency at which reception has been accepted as a reception frequency. 2. The transmitting means starts transmitting the confirming RF signal after transmitting the starting RF signal at all transmittable frequencies, and the receiving means transmits the starting RF signal from the transmitting terminal. 2. The communication system according to claim 1, wherein after receiving the start RF signal, reception of the check RF signal is started in synchronization with the transmission start timing of the check RF signal. 3. The transmission-side terminal further comprises transmission end output means for outputting, after the transmission of the confirmation RF signal by the transmission means, an indication that the transmission has been completed. 2. The communication system according to 1. 4. The communication system according to claim 1, wherein said receiving terminal further comprises a setting result output means for outputting a setting result of a reception frequency by said setting means. 5. A frequency setting method in a communication system comprising a transmitting terminal for transmitting an RF signal and a receiving terminal for receiving a signal transmitted from the transmitting terminal, wherein the transmitting terminal is A selection step of selecting a transmission frequency of the RF signal; and a confirmation R at the transmission frequency selected by the selection step.
A transmitting step of transmitting an F signal for a predetermined time, wherein the receiving terminal receives the confirmation RF signal transmitted from the transmitting terminal while sequentially switching a receiving frequency; and Setting a frequency at which reception has been accepted as a reception frequency. 6. In the transmitting step, after transmitting start RF signals at all transmittable frequencies, the confirming R signal is transmitted.
F transmission is started, and in the receiving step, after receiving the start RF signal transmitted from the transmitting terminal, receiving the confirmation RF signal in synchronization with the transmission start timing of the confirmation RF signal 6. The frequency setting method according to claim 5, further comprising: