JPH10107800A - Radio data communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce useless power consumption resulting from an excessive radio output power by selecting a radio output for radio data communication between a master station and a slave station to be a minimum power level by which a radio wave is reached between the stations in pairs. SOLUTION: A radio master station repeats transmission of a connection test message sequentially to each radio slave station (ST3). In this case, a radio output power for the message transmission is gradually being increased from a minimum level (ST5). Then a radio output when the master station receives a reply of a station at first is set to be a radio output with the replied radio slave station (ST6). Furthermore, the set radio output is informed to the related radio slave station (ST7). The radio slave station stores the noted radio output. After that, the radio communication between the master station and the slave station above is conducted by using the set radio output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wireless data communication system such as a wireless POS (point of sale information) system.

[0002]

2. Description of the Related Art FIG. 9 shows an example of a conventional wireless POS system. This POS system includes a terminal controller 1 composed of a host computer and the like, a transmission path 2
(N ≧ 2) wireless master stations 3A,..., 3N, and the number N of wireless master stations 3A,.
, POS terminals 4A-1, 4A-2,..., 4A-m,.
N-1, 4N-2,..., 4N-n respectively correspond to the wireless slave stations 5A-1,
5A-2, ..., 5A-m, ..., 5N-1, 5N-2, ..., 5N-n
Connect. The wireless slave stations 5A-1 to 5A-m, ..., 5N-1 to 5N-n belonging to the same group G1, ..., GN and the corresponding wireless master stations 3A, ..., 3N share a common radio frequency. , Each wireless master station 3
A,..., 3N and the subordinate wireless stations 5A-1 to 5A-
m,..., 5N-1 to 5N-n enable wireless data communication.

In such a wireless data communication system, the wireless output of each wireless master station 3A,.
Radio stations 5A-1 to 5A-m under their own control,
.., The value was set to an unnecessarily large value so that radio waves could reach all of 5N-1 to 5N-n. Therefore, for example, when a plurality of wireless master stations are installed on one floor, interference may occur unless the wireless frequencies used by the wireless master stations are different from each other. However, since the range of frequencies that can be allocated to such a wireless data communication system is narrow, it is not possible to install a large number of wireless master stations on one floor.

[0004]

As described above, in this type of conventional wireless data communication system, the wireless output of each wireless master station and wireless slave station is set to an unnecessarily large value. Power consumption was greater than necessary. Further, unless the radio frequencies used by the respective radio base stations are different from each other, a reduction in communication efficiency due to interference cannot be avoided.

The present invention has been made in view of such circumstances, and an object of the present invention is to reduce a radio output of radio data communication between a master station and a slave station to a minimum value at which radio waves can reach between the pair of stations. An object of the present invention is to provide a wireless data communication system that can be set to a level and can suppress wasteful power consumption due to excess wireless output.

[0006]

According to a first aspect of the present invention, a wireless master station is connected to a host device, and a wireless slave station is connected to each of a plurality of terminals. In a wireless data communication system that performs wireless data communication between the wireless master station, a test message transmitting means for wirelessly transmitting a connection test message to each wireless slave station in order to each wireless slave station, A wireless output varying means for varying a wireless output when transmitting a message, and a wireless output varying means for changing a wireless output to repeatedly transmit a connection test message, thereby enabling wireless communication for each wireless station. Wireless output setting means for setting a wireless output of a minimum level, and the wireless master station individually performs wireless communication with each wireless slave station with the wireless output set for each wireless slave station by the wireless output setting means. Those were Unishi. Further, the invention according to claim 2 of the present application provides the wireless slave station with a test message transmitting means, a wireless output varying means, and a wireless output setting means,
A wireless output notifying unit is provided for notifying a corresponding wireless station of a wireless output set for each wireless slave station by the wireless output setting unit, and each wireless slave station stores a wireless output notified from the wireless master station. Providing wireless output storage means for
The wireless master station individually performs wireless communication with each wireless slave station with the wireless output set for each wireless slave station by the wireless output setting means,
Each wireless slave station performs wireless communication with the wireless master station using the wireless output stored by the wireless output storage means.

Here, the wireless output setting means gradually increases the wireless output at the time of transmitting the connection test message from a preset initial level until a response from the wireless slave station of the transmission destination is received. Means for setting a wireless output when a response is first received as a wireless output with the wireless slave station can be considered. In addition, the wireless output when transmitting the connection test message is gradually lowered from a preset initial level until a response from the transmission destination wireless slave station is no longer received, and when the response is finally received. Means for setting the wireless output as the wireless output with the wireless slave station is also conceivable.

Further, the wireless master station individually performs wireless communication with each wireless slave station with the wireless output set for each wireless slave station by the wireless output setting means, and receives a response from the wireless slave station of the transmission destination. When it is not possible, a means for increasing the wireless output and retransmitting is provided, and each wireless station performs wireless communication with the wireless master station using the wireless output stored by the wireless output storage means, and responds from the wireless master station of the transmission destination. It is convenient to provide a means for increasing the radio output and retransmitting when the signal cannot be received.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In this embodiment, a case will be described in which the present invention is applied to the wireless POS system shown in FIG.

FIG. 1 is a block diagram showing a main configuration of each of the wireless master stations 3A,..., 3N connected to a terminal controller 1 via a transmission line 2. As shown in the figure, each of the wireless master stations 3A,.
(Central processing unit) 31, ROM (read only memory) in which a control program of the CPU 31 is stored in advance
32, S backed up by battery BT
A RAM (static random access memory) 33, a D-RAM (dynamic random access memory) 34 having an area for temporarily storing wireless transmission / reception data, a host interface for controlling data transmission with the terminal controller 1 35, a radio interface 3 for controlling data transmission with the radio circuit 36
7 and the like are connected by a bus line 38.

The radio circuit section 36 includes a transmission control section 36a for providing transmission data fetched via a radio section interface 37 to a modulation section 36b, a modulation section 36b for modulating transmission data and wirelessly transmitting the data from an antenna 39, an antenna. A demodulator 36c for demodulating the data received at 39;
It comprises a wireless receiving section 36d for providing the data demodulated in 6c to the wireless section interface 37.

As shown in FIG. 2, the S-RAM 33 includes a use channel setting area 33a for storing a radio frequency channel used by the own station, and a local communication address setting area for storing a communication address unique to the local station. 33b, and a slave station table 33c for storing a wireless output value corresponding to a communication address unique to each wireless slave station under its control.

FIG. 3 shows each of the POS terminals 4A-1 to 4A-m,
…, Wireless slave stations 5A mounted on 4N-1 to 4N-n, respectively
It is a block diagram which shows the principal part structure of -1-5A-m, ..., 5N-1-5N-n. As shown, the wireless slave stations 5A-1 to 5A
-m,..., 5N-1 to 5N-n are CPs constituting the control unit main body.
U51, a ROM 52 in which a control program of the CPU 51 is stored in advance, an S-RAM 53 backed up by a battery BT, a D-RAM 54 having an area for temporarily storing wireless transmission / reception data, a corresponding POS
Terminal interface 55 for controlling data transmission with terminals 4A-1 to 4A-m,..., 4N-1 to 4N-n, radio circuit unit 56
And a wireless unit interface 57 for controlling data transmission to and from them, and these are connected by a bus line 58.

The wireless circuit section 56 includes the wireless master stations 3A,
.., Like the 3N wireless circuit unit 36, the transmission control unit 56
a, modulation unit 56b, demodulation unit 56c, and wireless reception unit 56d
And controls wireless data transmission via the antenna 59. As shown in FIG. 4, the S-RAM 53 includes a use channel setting area 53a for storing a radio frequency channel used by the own station, a radio output setting area 53b for storing a radio output value, and communication specific to the own station. A local station communication address setting area 53c for storing an address and a parent station communication address setting area 53d for previously storing a communication address of one parent station capable of wireless communication with the own station are formed.

Thus, the S of each of the wireless master stations 3A,.
-The use channel setting area 33 is stored in the RAM 33 in advance.
a, the channel data of the radio frequency used by the own station is set, the communication address unique to the own station is set in the own station communication address setting area 33b, and the slave station table 33c stores information of each wireless slave station under the own station. Set each communication address.
In this case, the radio frequency sets different channel data only between the radio master stations adjacent to the radio zone. Channel data may overlap between wireless master stations that are not adjacent to wireless zones.

On the other hand, each of the wireless slave stations 5A-1 to 5A-m,.
In the S-RAM 53 of N-1 to 5N-n, a communication address unique to the own station is set in the own station communication address setting area 53c in advance. Also, channel data of a radio frequency used by one master station capable of wireless communication with the own station is set in the use channel setting area 53a, and the master station communication address setting area 53d is set.
Is set to the communication address of the master station. Further, a wireless output value Q is set in the wireless output setting area 53b. The wireless output value Q is set to a large value that ensures that radio waves reach the distance from the wireless master station that is the communication partner.

Thus, the S of each of the wireless master stations 3A,.
-RAM 33 and each of the wireless slave stations 5A-1 to 5A-m, ..., 5N
When the necessary data is set in the S-RAM 53 of -1 to 5N-n, the terminal controller 1 notifies the wireless master stations 3A,..., 3N of a connection test execution command. Then, each wireless master station 3A,.
In N, the CPU 31 starts the processing shown in the flowchart of FIG.

That is, first, as ST (step) 1, the table number counter A of the slave station table 33c is initialized to "1". In step ST2, the wireless output value P is set to the initial level P0. Note that this initial level P0
Is the minimum level of radio power in this system.

Next, as ST3, a slave station communication address is read from the table number area corresponding to the table number counter A of the slave station table 33c, and a connection test message using the slave station communication address as a destination address is edited. Then, the connection test message is wirelessly transmitted with the wireless output value P and the wireless frequency of the channel data set in the used channel setting area 33a (test message transmitting means).

Thereafter, in step ST4, a response message from the wireless slave station to which the connection test message is transmitted is awaited. And
If a normal response message to the connection test message cannot be received from the radio station within the predetermined time, the radio output P is increased by a predetermined value d in step ST5 (radio output variable means).
Then, returning to ST3, the connection test message is wirelessly transmitted to the wireless slave station with the wireless output value (P + d) and the same wireless frequency.

In this manner, the transmission of the connection test message is repeated while gradually increasing the radio output value P by a predetermined value d until a normal response message to the connection test message can be received from the wireless slave station. . If a normal response message to the connection test message is first received from the wireless slave station, the response message is stored in the table number area of the slave station table 33c corresponding to the table number counter A in step ST6. The wireless output value P of the connection test message when first received is set. This wireless output value P is the minimum level of wireless output required for wireless communication with the wireless slave station (wireless output setting means).

Next, in step ST7, the CPU 31 edits a setting message of the radio output value P using the slave station communication address of the radio station as a destination address, and converts the setting message to the same radio output value P and Radio transmission is performed to the wireless slave station at the radio frequency of the channel data set in the use channel setting area 33a (radio output notification means). Thereafter, in step ST8, the table number counter A is counted up by one. If it is confirmed in ST9 that the table number counter A does not exceed the number of slave stations set in the slave station table 33c, the process returns to ST2.

In this way, for each subordinate radio station,
The transmission of the connection test message is repeated while gradually increasing the wireless output by a predetermined value d. Then, the wireless output value P when a normal response message to the connection test message is first received for each wireless slave station is set in the slave station table 33c. Further, a message for notifying the set wireless output value is wirelessly transmitted to each wireless slave station. If the above processing is sequentially performed for each of the wireless slave stations obtained under the control, the CPU 31
Ends this processing.

On the other hand, each of the wireless slave stations 5A-1 to 5A-m,.
When receiving the connection test message having the communication address set in the master station communication address setting area 53a as the source address, the CPUs 51 of N-1 to 5N-n respectively start the processing shown in the flowchart of FIG. I do. First, in ST11, when it is confirmed that the received message is a connection test message, in ST12, the master station communication address setting area 53d is set.
And edits the normal response message with the communication address set as the transmission destination address, and sets the normal response message in the wireless output value Q set in the wireless output setting area 53b and the used channel setting area 53a. Wireless transmission at the radio frequency of the specified channel data.

Thereafter, as ST13, the process waits for a message for setting the radio output value P. Then, when this setting message is received in ST14, the wireless output value Q in the wireless output setting area 53b is changed to the wireless output value P in the received message (wireless output storage means), and this processing ends. .

As described above, in the wireless POS system according to the present embodiment, the terminal controller 1 sends each of the wireless master stations 3A,. When the connection test execution command is notified to 3N, each wireless master station 3A,
, 3N are the respective wireless slave stations 5A under their own control.
-1 to 5A-m,..., 5N-1 to 5N-n, wirelessly transmit a connection test message for each station.

In this case, first, the connection test message is transmitted with the wireless output as the preset minimum initial level. Then, if a response cannot be received from the destination wireless station, the wireless output is increased by the predetermined value d and the connection test message is transmitted again. In this way, transmission of the connection test message is repeated while gradually increasing the wireless output within the width of the predetermined value d until a response can be received from the wireless slave station of the transmission destination. Then, the wireless output value when the response is first received from the wireless slave station of the transmission destination, that is, between the wireless master station of the connection test message transmission source and the wireless slave station of the connection test message transmission destination Is determined as the wireless output value P with the wireless slave station, and the slave station table 33c
Is set and stored.

Each of the wireless master stations 3A,..., 3N receives a response from the wireless slave station to which the connection test message is transmitted, and determines the wireless output value P for the wireless slave station every time the wireless master station 3A,. The setting message of the wireless output value P is wirelessly transmitted to the slave station. The wireless output of this message is P. Thus, the wireless output value setting message is received by the wireless slave station, and the wireless output value P is stored in the wireless output setting area 53b of the wireless slave station.

Thereafter, each of the radio master stations 3A,..., 3N and the subordinate radio stations 5A-1 to 5A-m,.
Wireless communication with 5N-n is performed with a wireless output value P individually set between the master station and the slave station.

The radio output value P is an output of the minimum level required for radio communication between the corresponding master station and slave station, and the radio transmission data is correctly received by the other party due to some influence in the system environment. In some cases, it is not possible. Therefore, in such a case, as shown in FIG. 7, in both the wireless master station and the wireless slave station, as in the case of transmitting the connection test message, until a correct response is obtained from the transmission destination. Data transmission is repeated while increasing the wireless output in the increment d. The increase d may be the same as or different from the increase d in the connection test.

As described above, the wireless POS of the present embodiment is
According to the system, each wireless master station, 3A,..., 3N, and each wireless slave station 5A-1 to 5A-m,.
Wireless communication between 5N-1 to 5N-n is performed by a pair of master stations.
Since the wireless communication can be performed with the minimum level of wireless output at which radio waves can reach between the slave stations, wasteful power consumption during wireless communication can be suppressed. As a result, power consumption of the entire system can be reduced, and costs can be reduced.

.., 3N and each of the wireless slave stations 5A-1 to 5A-m,.
Wireless communication between 5N-1 to 5N-n is performed by a pair of master stations.
Since radio waves are transmitted at the minimum level at which radio waves can reach between slave stations, radio waves transmitted from one wireless master station to a wireless slave station under its own control are transmitted to a wireless slave under another wireless master station. It is unlikely to reach the bureau. Similarly, there is little possibility that a radio wave transmitted from a certain wireless slave station to its own master station will reach another master station. Therefore, interference does not occur as long as at least the radio frequency used between adjacent radio base stations in the radio zone is different, so that radio data having many radio base stations even in an environment where available radio frequencies are small. A communication system can be constructed.

When the wireless communication is performed at the minimum wireless output level at which radio waves can reach between the master station and the slave station and normal communication cannot be performed due to deterioration of the environment or the like, the wireless output is increased and retransmission is performed. I am trying to do it. Therefore, the communication efficiency is not reduced by setting the wireless output to the minimum level.

In the embodiment, the radio output of the connection test message is gradually increased from the minimum level in order to determine the minimum radio output value at which radio waves can reach between the pair of master station and slave station. However, the wireless output of the connection test message is gradually reduced from the maximum level until a response from the transmission destination wireless slave station is no longer received, and the wireless output when the response is finally received is reduced. The wireless station is determined as a wireless output with the wireless slave station, and the slave station table 3 of each wireless master station 3A,.
3c and each of the wireless slave stations 5A-1 to 5A-m, ..., 5N-1 to 5N
It is also possible to set in the -n wireless output setting area 53b.

FIG. 8 shows a connection test processing procedure of the CPU 31 in each of the wireless master stations 3A,..., 3N in this case. That is, first, the table number counter A of the slave station table 33c is initialized to "1" in ST21. Also,
In ST22, the wireless output value P is set to the initial level P0.
This initial level P0 is the maximum level of the wireless output in this system.

Next, as ST23, the slave station table 33c
The slave station communication address is read from the table number area corresponding to the table number counter A, and the connection test message having the slave station communication address as the destination address is edited, and the connection test message is wirelessly output. Radio transmission is performed with the value P and the radio frequency of the channel data set in the used channel setting area 33a (test message transmission means).

Thereafter, in ST24, a response message from the wireless slave station to which the connection test message is transmitted is awaited. If a normal response message to the connection test message can be received from the wireless station within a predetermined time, the wireless output P is reduced by a predetermined value d in step ST25 (wireless output variable means). Then, returning to ST23, the connection test message is wirelessly transmitted to the wireless slave station with the wireless output value (Pd) and the same wireless frequency.

In this manner, the transmission of the connection test message is performed while the radio output value P is gradually lowered by the predetermined value d until the normal response message to the connection test message is no longer received from the radio station. repeat. If a normal response message to the connection test message is no longer received from the wireless station, a predetermined radio output value P of the connection test message when the response message is no longer received is received in ST26. Value d
To obtain a wireless output P when a normal response message to the connection test message is finally received from the wireless slave station. Then, as ST27, the wireless output value P is set in the table number area corresponding to the table number counter A of the slave station table 33c. This wireless output value P
Is the minimum level wireless output required for wireless communication with the wireless slave station (wireless output setting means).

Next, in step ST28, the CPU 31 edits the setting message of the radio output value P using the slave station communication address of the corresponding radio station as the destination address, and converts the setting message to the same radio output value P and Radio transmission is performed to the wireless slave station at the radio frequency of the channel data set in the use channel setting area 33a (radio output notification means). After that, ST29
And increments the table number counter A by one. If it is confirmed in ST30 that the table number counter A does not exceed the number of slave stations set in the slave station table 33c, the process returns to ST22.

Thus, for each subordinate wireless station,
The transmission of the connection test message is repeated while gradually lowering the wireless output by a predetermined value d. Then, the wireless output value P at the time when the normal response message to the connection test message is received last for each wireless slave station is set in the slave station table 33c. Further, a message for notifying the set wireless output value P is wirelessly transmitted to each wireless slave station. The above processing is sequentially performed for each wireless slave station obtained under the control.

Also in such another embodiment, each wireless master station and 3A,..., 3N and each wireless slave station 5A-1 to 5A-m,. -n can be performed with a minimum level of wireless output that allows radio waves to reach between the pair of master station and slave station, so that the same operational effects as in the first embodiment can be obtained.

In each of the above embodiments, the increase width d when increasing the radio output of the connection test message or the decrease width d when decreasing the radio output is set to a constant value. The output may be increased or decreased, and after several times, the radio output may be increased or decreased with a small width. This has the effect of reducing the processing time required to set the minimum level of wireless output required for wireless communication.

In each of the above embodiments, the transmission of the connection test message from the wireless master station to the wireless slave station is repeated, and when the wireless output value is determined, the message for setting the wireless output value is transmitted. The wireless output value is set in the wireless slave station, but the wireless output value information of the message is included in the connection test message,
The wireless slave station extracts and sets the wireless output value of the message from the connection test message as its own wireless output value, that is, the wireless slave station updates the wireless output value each time it receives the connection test message You may make it. By doing this,
The process of transmitting a message for setting a wireless output value can be omitted.

In each of the above embodiments, the S-RAM
The memory areas shown in FIG. 2 and FIG. 4 are formed in 33 and 53, respectively.
The number is not limited to 3, 53, and may be any nonvolatile memory. In addition, it goes without saying that various modifications can be made without departing from the spirit of the present invention, such as applying the present invention to a wireless data communication system other than the wireless POS system.

[0045]

As described in detail above, according to the present invention,
The wireless data of the wireless data communication between the master station and the slave station can be set to a minimum level at which radio waves can reach between the pair of stations, and wireless data capable of suppressing wasteful power consumption due to excess wireless output. A communication system can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main configuration of a wireless master station according to an embodiment of the present invention.

FIG. 2 is a view showing a main memory area formed in the S-RAM of FIG. 1;

FIG. 3 is a block diagram showing a main configuration of a wireless slave station according to the embodiment;

FIG. 4 is a diagram showing a main memory area formed in the S-RAM of FIG. 3;

FIG. 5 is a flowchart showing a procedure of a connection test process executed by the CPU of the wireless master station according to the embodiment;

FIG. 6 is a flowchart showing a procedure of a connection test message reception process executed by the CPU of the wireless slave station in the embodiment.

FIG. 7 is a flowchart showing a wireless data transmission procedure of the wireless master station and the wireless slave station in the embodiment.

FIG. 8 is a flowchart showing a procedure of a connection test process executed by the CPU of the wireless master station according to another embodiment.

FIG. 9 is an overall view of a wireless POS system.

[Explanation of symbols]

 1: Terminal controller 3A,..., 3N: Wireless master station 4A-1 to 4A-m,..., 4N-1,. 5N-n: wireless slave stations 31, 51 CPU 33, 53 S-RAM 33c slave station table 53b wireless output setting area

Claims (5)

[Claims] 1. A wireless data communication system in which a wireless master station is connected to a host device and a wireless slave station is connected to each of a plurality of terminals to perform wireless data communication between the host device and each terminal. A test message transmitting unit that wirelessly transmits a connection test message to each of the wireless slave stations in turn, and a wireless output when the connection test message is transmitted by the transmitting unit; A wireless output varying means for setting a wireless output of a minimum level required for wireless communication for each wireless slave station by repeating transmission of the connection test message while changing a wireless output by the wireless output varying means. Wireless output setting means, wherein the wireless master station individually performs wireless communication with each of the wireless slave stations with a wireless output set for each wireless slave station by the wireless output setting means. Wireless data communication system according to claim. 2. A wireless data communication system in which a wireless master station is connected to a host device and a wireless slave station is connected to each of a plurality of terminals to perform wireless data communication between the host device and each terminal. A test message transmitting unit that wirelessly transmits a connection test message to each of the wireless slave stations in turn, and a wireless output when the connection test message is transmitted by the transmitting unit; A wireless output varying means for setting a wireless output of a minimum level required for wireless communication for each wireless slave station by repeating transmission of the connection test message while changing a wireless output by the wireless output varying means. Wireless output setting means, and a wireless output notifying means for notifying a corresponding wireless slave station of a wireless output set for each wireless slave station by the wireless output setting means, The wireless slave stations each include wireless output storage means for storing a wireless output notified from the wireless master station, and the wireless master station has a wireless output set for each wireless slave station by the wireless output setting means. Performing wireless communication with each of the wireless slave stations individually, wherein each of the wireless slave stations performs wireless communication with the wireless master station with the wireless output stored by the wireless output storage means. Communications system. 3. The wireless output setting means gradually increases the wireless output at the time of transmitting the connection test message from a preset initial level until receiving a response from a destination wireless station. 3. The wireless data communication system according to claim 1, wherein a wireless output when a response is first received is set as a wireless output with the wireless slave station. 4. A wireless output setting means for gradually lowering a wireless output when transmitting a connection test message from a preset initial level until receiving no response from a wireless slave station of a transmission destination. 3. The wireless data communication system according to claim 1, wherein a wireless output when a response is finally received is set as a wireless output with the wireless slave station. 5. The wireless master station individually performs wireless communication with each wireless slave station with the wireless output set for each wireless slave station by the wireless output setting means, and receives a response from the wireless slave station of the transmission destination. If you can not, increase the radio output and have a means to retransmit,
Each wireless slave station performs wireless communication with the wireless master station with the wireless output stored by the wireless output storage means, and increases the wireless output and retransmits when a response from the wireless master station of the transmission destination cannot be received. 3. The device according to claim 1, wherein
A wireless data communication system as described.