JPH0998176A - Device and method for transmitting data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accelerate transmission speed while keeping the quality of transmission by changing a communication procedure corresponding to the stored state of connection between a control station and respective slave stations. SOLUTION: A host computer 50 stores the state of connection with respective registers 60-62...6n and calculates (time-out) time for judging whether any specified register is operated or not corresponding to the connection state. A polling signal is sent from the host computer 50 to the specified register and when a response signal is returned within the calculated time-out time, it is judged that the specified register is operated. When the response signal shows the storage of bar code data, the host computer 50 transmits a specified register designate signal and receives the bar code data from the specified register. Based on the received bar code data, the host computer 50 retrieves correspondent merchandise price and transmits the merchandise price data to the specified register by the communication procedure corresponding to the stored connection state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission device and a data transmission method, and more particularly to maximizing a data transmission rate.

[0002]

2. Description of the Related Art Data transmission devices are used in various places, one of which is used in supermarkets. 2. Description of the Related Art In recent years, in a supermarket, a barcode attached to a product is read by a register at the time of payment, and a product price corresponding to the barcode is displayed on the register and used for the payment. Here, the bar code read by the register is sent to a host computer different from the register, and after the product price corresponding to the bar code is searched, the product price is sent to the register.

FIG. 15 shows the configuration of a data transmission device used in a supermarket. Data transmission device 100
, A plurality of registers 20 to 25 are provided in the store, the registers 20 to 24 are connected to the host computer 10 via a transmission line 35, and the register 25 is connected to the host computer 10 via radios 30a and 30b. It is connected to the.

The operation of such a data transmission device 100 will be described. The host computer 10 sequentially transmits polling signals to the registers 20 to 25.
The register receiving the polling signal returns a response signal indicating whether there is bar code data to be transmitted (read) to the host computer 10.

Here, in the case where the host computer 10 returns the response signal within a predetermined (timeout) time after the polling signal is transmitted, the register is operating, and the response is returned within the predetermined (timeout) time. If no signal is returned, then the register is determined to be inactive. As a result, the operating status of each register 20-25 is detected.

Upon receiving a response signal indicating that there is transmission bar code data from the register, the host computer 10 sends a signal designating the register. The register receiving the designation signal (designation register) transmits the barcode data to the host computer 10 based on the designation signal.

On the other hand, the host computer 10 receiving the bar code data from the designated register retrieves the price of the product corresponding to the bar code data. During the search for the commodity price, the host computer 10 sends a polling signal to the next register, and the register and the host computer 10 perform the same operation as described above.

When receiving a response signal indicating that there is no transmission bar code data from the register, the host computer 10 transmits a polling signal to the next register.

When the search for the product price is completed, the host computer 10 sends the product price to the designated register. When the commodity price is transmitted from the host computer 10 to the designated register, a communication error (if the commodity price data does not reach the designated register at all, only part of the commodity price data reaches the designated register) may occur.

When a communication error occurs, the host computer 10 retransmits the commodity price data to the designated register a predetermined number of times. That is, for example, when a communication error occurs with the designated register connected to the host computer 10 via the transmission line 35, the product price data is forced regardless of the reception of the communication completion signal from the designated register. Send twice. When a communication error occurs with the designated register connected to the host computer 10 via the radio, the product price data is forcibly forced three times regardless of the reception of the communication completion signal from the designated register. Send. This ensures that the product price data is sent to the designated register.

[0011]

However, the data transmission device 100 has the following problems. In the data transmission device 100, the timeout time is set for detecting the operating status of each register as described above.

However, the communication between the register 25 and the host computer 10 connected via the wireless device is performed by the transmission line 3
It takes longer than the communication with the registers 20 to 24 connected via the communication terminal 5.

Therefore, one register (register 2
5) is connected to the host computer 10 via the radios 30a and 30b, the timeout time must be uniformly set to the time when the radio is used.

That is, all the other registers 20 to 24
Is connected to the host computer 10 via the transmission line 35, the timeout time must be set to the time corresponding to the register 25.

As a result, the time-out time is lengthened only by the register 25. By using the lengthened time-out time for detecting the operating status of each register, the data transmission rate of the entire transmission device 100 is increased. There was a problem that it would decrease.

Further, in the data transmission device 100,
If a communication error occurs during the product price transmission as described above, the product price data is retransmitted to the designated register a predetermined number of times regardless of the reception of the communication completion signal from the designated register for reliable data transmission. There is.

However, the communication between the register 25 and the host computer 10 connected via the wireless device is performed by the transmission line 3
The communication error is more likely to occur than the communication with the registers 20 to 24 connected via the communication terminal 5.

Therefore, one register is the radio 30
When connected to the host computer 10 via a and 30b, the above-mentioned predetermined number of times must be uniformly set to the number of retransmissions (three times) when using the wireless device.

That is, all the other registers 20 to 24
Is connected to the host computer 10 via the transmission line 35, the number of retransmissions is three times corresponding to the register 25.

As a result, in order to perform reliable transmission (maintain the quality of transmission), the registers 20 to 2 which originally need to be retransmitted twice.
The number of retransmissions in 4 is performed three times in correspondence with the register 25.

Therefore, if the number of retransmissions becomes unnecessarily large and a communication error occurs, the data transmission rate of the entire transmission device 100 will decrease because the retransmission is performed more than the required number of times. there were.

Therefore, according to the present invention, while maintaining the quality of transmission,
An object of the present invention is to provide a data transmission device and a data transmission method capable of increasing the transmission speed.

[0023]

[Means for Solving the Problems]

[0024]

[Technical idea devised to solve the problem] [Technical idea devised to achieve the above object of providing a data transmission device and a data transmission method capable of increasing the transmission speed while maintaining the quality of transmission. The technical idea that was done is as follows.

That is, the number of stages in which the control station and each subordinate station are connected by wire transmission or wireless transmission is stored as a connection state between the control station and each subordinate station,
The communication method between the control station and each dependent station is changed according to the stored connection state between the control station and each dependent station.

Whether or not the dependent station is operating depends on whether or not a response signal from the dependent station to the inquiry signal is input within a predetermined time from the transmission of the transmission inquiry signal from the control station to the dependent station. Then, the presence or absence of the wireless transmission between the control station and the dependent station is determined based on the input time of the reaction signal input within the predetermined time.

Further, whether or not the dependent station is operating depends on whether or not the reaction signal from the dependent station to the inquiry signal is input within a predetermined time from the transmission of the transmission inquiry signal from the control station to the dependent station. And the number of wireless transmission steps interposed between the control station and the dependent station is determined based on the input time of the reaction signal input within the predetermined time.

Moreover, the communication method between the control station and the dependent station is changed according to the determined connection state between the control station and the dependent station.

The communication method between the control station and the dependent stations can be changed in accordance with the presence / absence of wireless transmission between the control station and each dependent station or the increase in the number of intervening wireless transmission steps. Is included. That is, add an error detection / correction code having higher error detection / correction performance. To shorten the unit block length in the communication between the control station and the dependent station. And changing the predetermined time, and determining whether or not each subordinate station is operating based on the changed predetermined time.

Further, when the communication method between the control station and the dependent station is changed, when a communication error occurs between the control station and the dependent station,
Increase the number of times the same data is transmitted as the communication between the control station and the dependent station, depending on the presence or absence of the wireless transmission between the control station and the dependent station or the number of stages of the wireless transmission interposed It is included.

Furthermore, in changing the communication method between the control station and the dependent station, the presence or absence of wireless transmission intervening between the determined control station and the dependent station or the number of intervening wireless transmission steps is performed. When the predetermined time is changed, it is determined whether or not each dependent station is operating based on the changed predetermined time, and when a communication error occurs between the control station and the dependent station,
Increase the number of times the same data is transmitted as the communication between the control station and the dependent station, depending on the presence or absence of the wireless transmission between the control station and the dependent station or the number of stages of the wireless transmission interposed It is included.

[0032]

[Definition of Terms] The concept of terms in the claims expressing the technical idea devised to solve the problems will be defined as follows, and the relationship between the terms and the embodiments of the invention will be described.

"Control station": A control station is a station that maintains communication with one or more subordinate stations connected thereto while communicating with the subordinate stations. In the embodiment of the present invention, the host computer 50 corresponds to this.

"Dependent station": A dependent station communicates with a control station under the initiative of the control station. In the embodiment of the present invention, the registers 60, 61, 62 ...
6n corresponds to this.

"Number of wireless transmission stages": The number of wireless transmission stages refers to how many pairs of wireless devices are interposed between a control station and a dependent station. In the case of a wired connection, there is no intervening wireless device, so the number is 0. In the embodiment of the present invention, there are 0 stages between the host computer 50 and the register 60, 1 stage between the registers 61 (radio devices 40a and 40b), and 2 stages between the registers 61 (shown in FIG. 1). Radios 40a, 40b, 40c and 40d).

"Connection state": The connection state is a state in which the control station and each subordinate station store the number of stages through which the wireless transmission is connected. In the embodiment of the present invention, It refers to the storage state of the attribute value M shown in FIG.

"Communication technique": The communication technique is a technique used in communication between a control station and each subordinate station. It can be said that the communication methods are different when the communication protocols are different, and the communication methods are different even when the communication control parameters are different even if the communication protocols are the same. In the embodiment of the present invention, the communication method can be changed by changing at least one of the error detection / correction signal, the block length, the time-out time, and the number of times of resending the commodity price data.

"Transmission inquiry signal": The transmission inquiry signal is a signal transmitted by the control station to the dependent station,
When the subordinate station stores data to be transmitted to the control station, it is a signal for causing the control station to transmit the data.
In the embodiment of the present invention, the polling signal corresponds to this.

"Reaction signal input time": The reaction signal input time means the time elapsed from the polling signal transmission of the control station until the reaction (response) signal transmitted by the subordinate station is input to the control station.

[0040]

In the data transmission device or the data transmission method according to claim 1, claim 8, claim 15, claim 21, claim 23 and claim 25, the stored or judged control station. And the communication method between the control station and each subordinate station is changed according to the connection state of each subordinate station. Therefore, it is possible to maximize the communication speed while maintaining the quality of communication.

In the data transmission device according to claim 2, claim 9 or claim 16, the control unit responds to the presence or absence of wireless transmission between the control station and each subordinate station or an increase in the number of wireless transmission stages. Then, an error detection / correction code having higher error detection / correction performance is added. Therefore, it is possible to maximize the communication speed while detecting / correcting the data sent by mistake.

In the data transmission device according to claim 3, claim 10 and claim 17, the control unit responds to the presence or absence of wireless transmission between the control station and each subordinate station or an increase in the number of wireless transmission stages. Then, the unit block length in the communication between the control station and the dependent station is shortened. Therefore, it is possible to maximize the communication speed while reducing the number of errors that occur for each block.

In the data transmission device according to claim 4, claim 11 and claim 18, the control unit increases or determines the number of stages of wireless transmission between the stored or determined control station and each subordinate station. A predetermined time corresponding to the presence or absence of wireless transmission between the control station and each subordinate station is calculated, and it is determined whether each subordinate station is operating based on the determined predetermined time. Therefore, the communication speed can be maximized by using the optimum determination time according to the number of wireless transmission stages.

In the data transmission device according to claim 5, claim 12 or claim 19, the control unit is stored or judged when a communication error occurs between the control station and the dependent station. The number of times of transmitting the same data as the communication between the control station and the dependent station is increased according to the presence or absence of wireless transmission between the dependent stations and the number of stages of wireless transmission. Therefore, even in the case of a communication error, the communication speed can be maximized by resending the communication data.

In the data transmission device according to claim 6, claim 13 and claim 20, the controller increases or judges the number of wireless stages between the stored or judged control station and each subordinate station. A predetermined time corresponding to the presence or absence of wireless transmission between the control station and each dependent station is calculated, and it is determined whether or not each dependent station is operating based on the calculated predetermined time. When a communication error occurs between the two, depending on the number of stages of wireless transmission between the stored or determined control station and the dependent station or the presence or absence of wireless transmission between the determined control station and each dependent station, The number of times of transmitting the same data as the communication between the control station and the dependent station is increased. Therefore, it is possible to maximize the communication speed by using the optimum determination time according to the number of wireless transmission steps and retransmitting the communication data even in the case of a communication error.

In the data transmission device or data transmission method according to claim 7, claim 14, claim 22 or claim 24, the inquiry is made within a predetermined time from the transmission of the transmission inquiry signal from the control station to the subordinate station. It is determined whether or not the dependent station is operating, depending on whether or not the reaction signal from the dependent station is input to the signal, and the control station is determined based on the input time of the reaction signal input within the predetermined time. The presence or absence of wireless transmission between the dependent stations or the number of wireless transmission stages between the control station and the dependent station is determined. Therefore, it is possible to maximize the speed of judgment while maintaining the quality of judgment.

[0047]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a data transmission device and a data transmission method according to the present invention will be described below with reference to the drawings. FIG. 1 shows the connection of the data transmission device 200. The data transmission device 200 of the present embodiment is provided in a store of a supermarket, and registers 60, 61, 62 ... 6n which are subordinate stations are connected to a host computer 50 as a control station via a transmission line or a radio. ing.

The register 60 is connected to the host computer 50 as a control station via the transmission line 35, and the register 61 is connected to the host computer 50 via the wireless devices 40a and 40b (wireless one stage). In addition, the register 62 includes radios 40a, 40b, 40c and 40d.
It is connected to the host computer 50 via (wireless two stages). Further, each register up to the register 6n is also connected to the host computer 50.

The register 61 is a register provided when it is not possible to connect to the host computer 50 via the transmission line 35 due to the layout of the store. Further, the register 62 is a special register provided in association with the register 61 in preparation for congestion.

FIG. 2 shows the configuration of the host computer 50. The host computer 50 includes a CPU 51 that is a control unit and an operation determination unit, a hard disk 54 that is a connection state storage unit, an internal memory 52, and a timer 53. The respective parts are connected by an internal bus line 36.

FIG. 3 shows registers 60, 61, 62 ... 6n.
Shows the configuration of. The registers 60, 61, 62, ... 6n have the same configuration and are provided with a CPU 31, a hard disk 34, an internal memory 32, and a barcode reader 33. The respective parts are connected by an internal bus line 36.

The bar code reader 33 reads the bar code attached to the product placed in the supermarket, and the CPU 31 stores the read bar code in the hard disk 34.

Data transmission device 2 having such a configuration
The operation of 00 will be described. FIG. 4 and FIG. 5 show operation flowcharts of the CPU 51 on the side of the host computer 50 which operates according to the program stored in the internal memory 52. In addition, in FIG.
2 shows an operation flowchart of the CPU 31 on the register side which operates according to the program stored in FIG. here,
Assume that the register 61 is a specific register.

First, the host computer 50 fetches the attribute value indicating the connection state between the specific register and the host computer 50 stored in advance in the hard disk 54 (FIG. 4, step S10). In FIG. 7, the hard disk 5
4 shows the storage state of the host computer 50 and the attribute value M of each register. Here, the attribute value M of the register 60 connected to the host computer 50 via the transmission line 35 (wired) is 0, and the register 61 connected via the wireless first stage (wireless devices 40a and 40b).
Has an attribute value M of 1 and wireless 2 stages (radio devices 40a, 40b, 4
0c and 40d) connected to the register 61
The attribute value M of is stored as 2 (see FIG. 1).

That is, the host computer 50 specifies a certain register and takes in the attribute value M indicating the connection state between the host computer 50 and the specific register. That is,
The host computer 50 takes in the attribute value (1) of the register 61 (see FIG. 7).

Next, the host computer 50 sends a polling signal to the specific register (FIG. 4, step S).
12). That is, the host computer 50 sends a signal to the specific register 61 to send the data stored in the register.

FIG. 8 shows a polling signal transmitted from the host computer 50 to the specific register 61. Addressing the polling signal is to prevent the polling signal from being received by a register other than the specific register because a plurality of registers are connected to the host computer 50 via one transmission line or radio. Is.

After transmitting the polling signal, the host computer 50 calculates the time-out time according to the connection state with the specific register (FIG. 4, step S14). That is, the host computer 50 calculates the time (timeout time) for judging the operation of the specific register using the fetched attribute value M. The timeout time TO for the specific register is calculated by the following formula.

TO = M (attribute value) × MT (round-trip communication time between wireless devices) + YT (timeout time of register connected by wire) For example, round-trip communication time MT (communication in FIG.
Assuming that the time (reciprocating in the space 45 shown in 1) is 0.2 seconds, the timeout time TO for the specific register 61 is calculated to be 1 × 0.2 seconds + YT. That is, the timeout time for the specific register 61 is
It is calculated to be 0.2 seconds longer than the timeout time of the register (register 60) in the case of wired connection.

The polling signal transmitted from the host computer 50 is transmitted via the transmission line and the radios 40a and 40b, and the specific register 61 receives the polling signal from the host computer 50 (FIGS. 1 and 6). Step S50).

Next, the specific register 61 determines whether or not the received polling signal is for itself (FIG. 6, step S52). When it is determined that the polling signal is for itself, the specific register 61 determines whether or not the barcode data to be transmitted is stored (step S54). That is, it is determined whether or not the bar code is stored in the hard disk 34.

Next, when the specific register 61 stores the bar code data, it transmits a response signal indicating that the bar code is stored to the host computer 50 (step S56) and stores the bar code data. If not,
A response signal indicating that the barcode data is not stored is transmitted to the host computer 50 (step S57).

FIG. 9A shows a response signal indicating that the barcode data is stored, and FIG. 9B shows a response signal indicating that the barcode data is not stored.

The host computer 50 executes step S1.
It is determined whether or not the response signal from the specific register 61 is input within the timeout time calculated in step 4 (FIG. 4, step S16).

If the response signal is input within the timeout time, it is determined that the specific register 61 is operating (step S18), and if the response signal is not input within the timeout time, the specific register 61 is not operating. Is determined (step S17). That is, regardless of whether or not the specific register 61 stores bar code data, when the response signal is input within the calculated timeout time, it is determined that the specific register 61 is operating.

In this way, the timeout time is calculated according to the connection state of the host computer 50 and the specific register stored in advance, and whether the specific register is operating or not is determined based on the calculated timeout time. Therefore, the communication speed can be maximized by using the optimum determination time according to the number of wireless transmission stages.

When it is determined that the specific register 61 is operating, the host computer 50 determines whether or not the input response signal has a content storing bar code data (step S20). If the response signal does not store the bar code data, the host computer 50 sets the next register as the specific register (step S21). That is, when the response signal does not store the bar code data, the host computer 50 performs the above operation with the register 62 as the specific register.

On the other hand, when it is determined that the response signal has the contents storing the bar code data, the host computer 50 transmits the designation signal to the specific register 61 (step S22). FIG. 10 shows a designation signal transmitted from the host computer 50 to the specific register 61.

The specific register 61 receives the designation signal from the host computer 50 (FIG. 6, step S5).
8) The bar code data stored in the hard disk 34 is transmitted to the host computer 50 (step S).
60). FIG. 11 shows the bar code data transmitted from the specific register 61 to the host computer 50.

The bar code data transmitted from the specific register 61 is received by the host computer 50 (step S24 in FIG. 5), and the host computer 50
Is the product price corresponding to the received barcode data,
The database in the hard disk 54 is searched (step S26).

When the commodity price search is completed and the commodity price data is transmitted from the host computer 50 to the specific register 61, the CPU 51 obtains the attribute value M indicating the connection state with the specific register 61 stored in the hard disk 54. (See FIG. 7). The host computer 50 transmits the product price data to the specific register 61 by the communication method according to the connection state with the specific register (step S28).

FIG. 12 shows the commodity price data transmitted from the host computer 50 to the specific register 61. The reason why the bar code data is transmitted together with the commodity price data is to collate with the bar code data transmitted in the specific register 61.

There are the following communication methods depending on the connection state with the specific register. As one of them, the communication block length is shortened as the number of wireless stages increases. That is, for example, assume that the communication block length of the commodity price data is 256 bits when the host computer 50 and the specific register are connected via a transmission line.

Here, when the host computer 50 and the specific register are connected via the first stage of the radio, communication is performed with the communication block length being 128 bits, which is half 256 bits. Further, when the specific register is connected to the host computer 50 through the two stages of the radio, communication is performed with the communication block length being 64 bits, which is half 128 bits.

The reason for changing the communication block length in this way is as follows. If the product price data is surely transmitted to the specific register, the block length may be shortened, but the communication speed is reduced. On the other hand, in order to maximize the communication speed, the block length may be increased, but reliable communication cannot be performed. Therefore, by communicating with the communication block length according to the increase in the number of wireless stages, the product price data can be reliably transmitted to the specific register, and
This is to maximize the communication speed.

As another communication method, an error detection / correction code having a higher error detection / correction performance is added as the number of wireless stages increases. That is, for example, when the host computer 50 and the specific register are connected via a transmission line, a parity check code is added to the product price data, and the specific register is connected via one stage of the radio device. , CRC code is added. Further, when the specific register is connected to the host computer 50 via the two-stage radio, a CRC code having high error detection / correction performance is added to the product price data.

The reason why the performance of the error detection / correction code is changed in this way is as follows. In order to surely send the commodity price data to the specific register, a high-performance (long) error detection / correction code may be added, but the communication speed decreases. On the other hand, in order to maximize the communication speed, an error detection / correction code having low performance (short) may be added, but reliable communication cannot be performed. Therefore, by adding the error detection / correction code of the performance according to the increase in the number of wireless stages, the product price data is surely transmitted to the specific register and the communication speed is maximized.

When the commodity price data is transmitted from the host computer 50 by the communication method as described above, the specific register 61 determines whether or not the commodity price data is received (FIG. 6, step S62). When the product price data is not completely received, the specific register 61 transmits a communication incompletion signal to the host computer 50 (step S).
63).

After transmitting the commodity price data, the host computer 50 determines whether or not a communication error has occurred (FIG. 5, step S30). Here, the occurrence of the communication error means that the host computer 50 receives the communication non-completion signal or the communication completion signal from the specific register 61.

When a communication error occurs, the CPU 51
Takes in the attribute value M (see FIG. 7) indicating the connection state with the specific register stored in the hard disk 54 and transmits the commodity price data to the specific register 61 as many times as the number of times corresponding to the connection state with the specific register (step S32). For example, when the host computer 50 and the specific register are connected via a transmission line, the product price data is retransmitted once, and when it is connected via the first stage of the wireless device, it is retransmitted twice. To do. Further, when the specific register is connected to the host computer 50 via the two-stage radio, the product price data is retransmitted three times.

The reason for changing the number of resends of the commodity price data in this way is as follows. If it is attempted to reliably transmit the commodity price data to the specific register, the number of retransmissions should be increased when a communication error occurs, but the communication speed will decrease. On the other hand, in order to maximize the communication speed, it is sufficient to reduce the number of retransmissions, but reliable communication cannot be performed.
Therefore, the product price data is reliably transmitted to the specific register and the communication speed is maximized by retransmitting the product price data as many times as the number of wireless stages increases.

If it is determined in step S30 that no communication error has occurred, the next register (register 62) is set as the specific register (step S3).
4). As a result, the above-described operation is performed in the register 62 which has become a new specific register and the host computer 50. In this way, the registers are specified in order until the special register reaches the register 6n, and after the special register becomes 6n, the register 60 is returned to. That is,
The specification of the register is sequentially and repeatedly performed from the register 60 to the register 6n.

When the specific register 61 receives the complete product price data, it sends a communication completion signal to the host computer 50 (FIG. 6, step S64) and performs settlement using the received product price data (step S66). . That is, the specific register 61 receives the commodity price based on the barcode of the commodity read by the barcode reader 33, and uses the commodity price to settle the purchase in the store.

As described above, in the data transmission device 200 of this embodiment, the host computer 5 stored in advance is stored.
The optimum determination time is used to determine the operation of the specific register according to 0 and the connection state of each register, and the communication method is changed according to the connection state.

Therefore, it is possible to use the optimum judgment time according to the number of wireless stages and maximize the communication speed while maintaining the communication quality.

Next, another embodiment of the data transmission device and the data transmission method according to the present invention will be described. The data transmission device and the data transmission method according to the present embodiment are provided with a connection state between the host computer 50 and a specific register (host computer
Whether or not there is a wireless connection between 0 and the specific register, the number of wireless connection stages) is automatically determined, and the communication method is changed based on the determined connection state. That is, in this embodiment,
Unlike the data transmission device of the above-described embodiment, the connection state is not stored in advance, but the connection state is determined based on the input time of the response signal from the specific register issued in response to the polling signal.

A data transmission device having such characteristics will be described. The data transmission device of this embodiment has the same configuration as the data transmission device 200 shown in FIG. 1, and is installed in a supermarket store. In addition, the host computer 50 and the registers 60 and 61,
The configuration of 62 ... 6n is also as shown in FIGS. 2 and 3.

The operation of the data transmission apparatus according to this embodiment will be described. 13 and 14, the host computer 5 that operates according to the program stored in the internal memory 52.
The operation | movement flowchart of CPU51 by the side of 0 is shown. In addition,
The operation of the CPU 31 on the register side is the same as that of the flowchart shown in FIG.

First, the host computer 50 sends a polling signal to the specific register (FIG. 13, step S80). The polling signal shown in FIG. 8 is transmitted from the host computer 50 to the specific register. Here again, the present embodiment will be described assuming that the register 61 is a specific register.

The polling signal transmitted from the host computer 50 is transmitted via the transmission line and the radios 40a and 40b, and the specific register 61 receives the polling signal (FIG. 6, step S50). Upon receiving the polling signal, the specific register 61 causes the steps S52 and S5.
4, the operations of S56 and S57 are performed. The response signal (S56) indicating that the bar code data is stored and the response signal (S57) indicating that the bar code data is not stored are the same as those shown in FIGS. 9A and 9B. Similar signal.

Next, the host computer 50 determines whether or not the response signal is input from the specific register 61 within a predetermined time (FIG. 13, step S82). Here, if the response signal from the specific register 61 is input within the predetermined time, it is determined that the specific register 61 is operating (step S84), and if not input, the specific register 61 operates. It is determined that it is not (step S83).

If it is determined in step S83 that the specific register 61 is not operating, the host computer 50 sets the next register (register 62) as the specific register (step S85).

On the other hand, if it is determined in step S84 that the specific register 61 is operating, the connection state between the host computer 50 and the specific register is determined based on the input time of the response signal from the specific register 61. (Step S86). That is, the connection state between the host computer 50 and the specific register 61 is determined according to the elapsed time from the polling signal transmission to the response signal input within the predetermined time in step S82. Here, based on the elapsed time, whether the specific register 61 is connected to the host computer 50 via the transmission line (wired), or the wireless 1
Stage or wireless 2 stages.

The elapsed time from the transmission of the polling signal to the input of the response signal is short in the order of wired connection, connection through the first wireless step, and connection through the second wireless step. Therefore, if the elapsed time from the polling signal transmission to the response signal input is within the shortest range (for example, 0.2 seconds from the polling signal transmission), it is determined that the connection state is the wired connection, and the elapsed time is If it is within a very short range (for example, 0.3 to 0.5 seconds), it is determined that the connection is via the wireless first stage. further,
When the elapsed time is within the longest range (for example, 0.6 to 0.8 seconds), it is determined that the connection state is the connection via the two wireless stages.

The connection state between the host computer 50 and the specific register 61 determined as described above is stored as an attribute value M in the hard disk 54 as shown in FIG.

The operation of the host computer 50 after step S86 in this embodiment is similar to the operation of the host computer 50 of the above embodiment (see FIG. 4, steps S20 to 5, and step S34). The operation of each register is the same as in the above embodiment (see FIG. 6).

In the above embodiments, the data transmission device used in the supermarket has been described. However, the data transmission device according to the present invention may be used in other applications as long as the dependent station is connected to the control station by wire or wirelessly and the price and the like are instructed by inquiring about the price and the like. You may make it use for an application, for example, a gas station.

Further, in the above embodiment, both the host computer 50 and the registers 60 to 62 ... 6n are realized by using the CPU. However, these may be realized by hardware logic without using the CPU.

Further, in the above embodiment, the bar code reader is used to read the bar code of the product. However, if the product bar code is printed in a predetermined format and is optically readable, then it is OCR (optical code reader) or M if it is magnetically readable.
An ICR (magnetic code reader) may be used. Further, the barcode may be input using a keyboard instead of being read by using the above device.

In the above embodiment, as one of the changes in the communication method, when the host computer 50 and the specific register are connected through one stage of the radio, the communication block length is 128 bits, which is half 256 bits. When connecting via two stages of wireless devices, communication was performed with a communication block length of 64 bits. However, the block length may be further shortened if reliable and quick communication can be performed.

Further, in the above embodiment, as another communication method change, a parity check code is added to the commodity price data or a CRC is added to the commodity price data according to the increase in the number of wireless stages.
A sign is added. However, accurate error detection /
If correction is possible, an error detection / correction signal may be added to the commodity price data by another method, for example, an FEC (forward error correction) method may be used.

Further, in the above embodiment, when a communication error occurs when transmitting the commodity price data to the specific register, the commodity price data is transmitted to the specific register 61 as many times as the number of times depending on the connection state with the specific register. ing. That is, when the host computer 50 and the specific register are connected via a transmission line, the product price data is set to 1
Twice, if the connection is made via the first stage of the wireless device, then twice, and if the connection is made via the second stage of the wireless device, the product price data is retransmitted three times. However, the number of times of retransmission may be increased or decreased as long as reliable and quick communication can be performed.

In the above embodiment, the method of shortening the communication block length as the change of the communication method or the method of adding the error detection / correction code having higher error detection / correction performance has been described. However, if reliable and quick communication can be performed, the communication method may be changed to shorten the communication block length and add an error detection / correction code having higher error detection / correction performance.

In the above embodiment, the communication method is changed in accordance with the connection state between the host computer 50 and the specific register by shortening the communication block length, adding an error detection / correction signal, and selling the product. The method of retransmitting data is adopted.

However, when trying to maintain the quality of communication, the communication speed decreases, and conversely, when trying to maximize the communication speed,
Any method can be adopted in the present invention as long as it is a communication method that reduces the quality of communication.

[Brief description of drawings]

FIG. 1 is a diagram showing a connection of a data transmission device according to the present invention.

FIG. 2 is a block diagram showing a configuration of a host computer shown in FIG.

FIG. 3 is a block diagram showing a configuration of each register shown in FIG.

FIG. 4 is a flowchart showing the operation of a CPU on the host computer side.

FIG. 5 is a flowchart showing the operation of a CPU on the host computer side.

FIG. 6 is a flowchart showing an operation of a CPU on a specific register side.

FIG. 7 is a diagram showing a connection state (attribute value M) between a host computer and registers stored in a hard disk in the host computer.

FIG. 8 is a diagram showing the contents of a polling signal transmitted from a host computer to a specific register.

FIG. 9 is a diagram showing the contents of a response signal transmitted from a specific register to a host computer.

FIG. 10 is a diagram showing the contents of a designation signal transmitted from a host computer to a specific register.

FIG. 11 is a diagram showing the contents of bar code data transmitted from a specific register to a host computer.

FIG. 12 is a diagram showing the content of product price data transmitted from a host computer to a specific register.

FIG. 13 is a flowchart showing the operation of the CPU on the host computer side.

FIG. 14 is a flowchart showing the operation of the CPU on the host computer side.

FIG. 15 is a diagram showing a connection state of a conventional data transmission device.

[Explanation of symbols]

 50 ... Host computer 60-62 ... 6n ... Register

Claims (26)

[Claims] 1. A control station that transmits and receives data and control signals to and from a plurality of subordinate stations, and a subordinate that transmits and receives data and control signals to and from the control station via wired or wireless transmission. In the data transmission device including a station, the control station stores, as a connection state between the control station and each subordinate station, a connection state memory that stores how many stages the control station and each subordinate station are connected by radio transmission. Unit, and a control unit for changing the communication method between the control station and each dependent station according to the connection state of the control station and each dependent station stored in the connection state storage unit, . 2. The data transmission device according to claim 1, wherein the control unit has higher error detection / correction performance in response to an increase in the number of wireless transmission stages interposed between the control station and each dependent station. A data transmission device, wherein the communication method is changed so as to add an error detection / correction code. 3. The data transmission device according to claim 1, wherein the control unit is provided between the control station and the subordinate station in response to an increase in the number of wireless transmission steps interposed between the control station and each subordinate station. A data transmission device, characterized in that the communication method is changed so as to shorten a unit block length in communication. 4. The data transmission device according to claim 1, wherein the control unit receives a reaction signal from the dependent station in response to the inquiry signal within a predetermined time after transmission of a transmission inquiry signal from the control station to the dependent station. It includes an operation determination unit that determines whether the dependent station is operating depending on whether or not the dependent station is operating, and the wireless transmission of the transmission between the control station and each dependent station stored in the connection state storage unit is included. Calculating a predetermined time corresponding to an increase in the number of stages and changing the communication method so as to judge whether or not each subordinate station is operating based on the calculated predetermined time. . 5. The data transmission device according to claim 1, wherein when a communication error occurs between the control station and the subordinate station, the control unit stores the control station and the subordinate station stored in the connection state storage unit. The data transmission device is characterized in that the communication method is changed so as to increase the number of times of transmitting the same data as the communication between the control station and the dependent station, corresponding to the number of wireless transmission steps interposed therebetween. . 6. The data transmission device according to claim 1, wherein the control unit receives a reaction signal from the dependent station in response to the inquiry signal within a predetermined time after transmitting a transmission inquiry signal from the control station to the dependent station. It includes an operation determination unit that determines whether the dependent station is operating depending on whether or not the dependent station is operating, and the wireless transmission of the transmission between the control station and each dependent station stored in the connection state storage unit is included. Calculate a predetermined time corresponding to the increase in the number of stages, and determine whether each dependent station is operating based on the calculated predetermined time, if a communication error occurs between the control station and the dependent station, To increase the number of times of transmitting the same data as the communication between the control station and the dependent station, corresponding to the number of wireless transmission stages interposed between the control station and the dependent station stored in the connection state storage unit. Changing the communication method A data transmission device characterized by: 7. A control station that transmits and receives data and control signals to and from a plurality of dependent stations, and is connected to the control station via wired transmission or wireless transmission, and transmits and receives data and control signals to and from the control station. In the data transmission device comprising: a dependent station that transmits and receives a control signal, the control unit is configured such that a response signal from the dependent station to the inquiry signal is received within a predetermined time from the transmission of the transmission inquiry signal from the control station to the dependent station. It includes an operation determination unit that determines whether or not the dependent station is operating depending on whether or not it is input, and the control station and the dependent station based on the input time of the reaction signal input within the predetermined time. A data transmission device, characterized in that the presence or absence of intervening wireless transmission between stations is determined. 8. The data transmission device according to claim 7, wherein the control unit changes a communication method between the control station and the dependent station according to a connection state between the control station and the dependent station determined by the operation determination unit. A data transmission device comprising: 9. The data transmission device according to claim 8, wherein the control unit detects / corrects an error in the wireless transmission depending on whether or not the wireless transmission is interposed between the control station and each dependent station. A data transmission device, characterized in that the communication method is changed so as to add a high-performance error detection / correction code. 10. The data transmission device according to claim 8, wherein the control unit determines whether the control station and the radio station perform radio transmission in response to presence or absence of radio transmission interposed between the control station and each subordinate station. A data transmission device, wherein the communication method is changed so as to shorten a unit block length in communication between dependent stations. 11. The data transmission device according to claim 8, wherein the control unit responds to the wireless transmission in response to the presence or absence of wireless transmission interposed between the determined control station and each dependent station. A data transmission device, wherein a predetermined time is changed, and the communication method is changed so as to determine whether or not each subordinate station is operating based on the changed predetermined time. 12. The data transmission device according to claim 8, wherein when a communication error occurs between the control station and the dependent station, the control unit determines between the control station and the dependent station determined by the operation determining unit. Corresponding to the presence or absence of wireless transmission intervening in
A data transmission device, characterized in that the communication method is changed so as to increase the number of times of transmitting the same data as the communication between the control station and the dependent station with respect to wireless transmission. 13. The data transmission device according to claim 8, wherein the control unit responds to the wireless transmission in response to the presence or absence of wireless transmission interposed between the determined control station and each dependent station. The predetermined time is changed, and it is determined whether or not each dependent station is operating based on the changed predetermined time. When a communication error occurs between the control station and the dependent station, the operation determination unit determines. The number of times of transmitting the same data as the communication between the control station and the dependent station is increased in response to the presence or absence of the wireless transmission between the control station and the dependent station. A data transmission device characterized by changing a communication method. 14. A control station that transmits and receives data and control signals to and from a plurality of subordinate stations, and is connected to the control station via wired transmission or wireless transmission, and transmits data to and from the control station. In the data transmission device comprising: a dependent station that transmits and receives a control signal, the control unit is configured such that a response signal from the dependent station to the inquiry signal is received within a predetermined time from the transmission of the transmission inquiry signal from the control station to the dependent station. It includes an operation determination unit that determines whether or not the dependent station is operating depending on whether or not it is input, and the control station and the dependent station based on the input time of the reaction signal input within the predetermined time. A data transmission device characterized by determining the number of wireless transmission steps interposed between stations. 15. The data transmission device according to claim 14, wherein the control unit changes a communication method between the control station and the dependent station according to a connection state between the control station and the dependent station determined by the operation determination unit. A data transmission device comprising: 16. The data transmission device according to claim 15, wherein the control unit has higher error detection / correction performance in response to an increase in the number of wireless transmission stages interposed between the control station and each subordinate station. A data transmission device, wherein the communication method is changed so as to add an error detection / correction code. 17. The data transmission device according to claim 15, wherein the control unit is provided between the control station and the subordinate station in response to an increase in the number of wireless transmission steps interposed between the control station and each subordinate station. A data transmission device, characterized in that the communication method is changed so as to shorten a unit block length in communication. 18. The data transmission device according to claim 15, wherein the control unit changes the predetermined time in response to an increase in the number of wireless transmission steps interposed between the determined control station and each subordinate station. A data transmission device, wherein the communication method is changed so as to determine whether or not each subordinate station is operating based on a predetermined time after the change. 19. The data transmission device according to claim 15, wherein the control unit is arranged between the control station and the dependent station determined by the operation determining unit when a communication error occurs between the control station and the dependent station. Corresponding to the number of stages of wireless transmission intervening in
A data transmission device, wherein the communication method is changed so as to increase the number of times of transmitting the same data as the communication between the control station and the dependent station. 20. The data transmission device according to claim 15, wherein the control unit responds to wireless transmission in response to presence / absence of wireless transmission interposed between the determined control station and each dependent station. The predetermined time is changed, and it is determined whether or not each dependent station is operating based on the changed predetermined time. When a communication error occurs between the control station and the dependent station, the operation determination unit determines. The number of times of transmitting the same data as the communication between the control station and the dependent station is increased in response to the presence or absence of the wireless transmission between the control station and the dependent station. A data transmission device characterized by changing a communication method. 21. A data transmission method for transmitting and receiving data and control signals to and from a plurality of subordinate stations, and transmitting and receiving data and control signals to and from the control station via wired transmission or wireless transmission. , The connection status between the control station and each subordinate station is stored as the connection status between the control station and each subordinate station, and the connection status between the control station and each subordinate station is stored as the connection status between the control station and each subordinate station. The data transmission method is characterized in that the communication method between the control station and each dependent station is changed according to. 22. A data transmission method for transmitting and receiving data and control signals to and from a plurality of dependent stations, and transmitting and receiving data and control signals to and from the control station via wired transmission or wireless transmission. , It is judged whether or not the dependent station is operating depending on whether or not the response signal from the dependent station to the inquiry signal is input within a predetermined time from the transmission of the inquiry signal from the control station to the dependent station. Determining the presence or absence of wireless transmission between the control station and the dependent station based on the input time of the reaction signal input within the predetermined time. 23. The data transmission method according to claim 22, wherein the communication method between the control station and the dependent station is changed according to the determined connection state between the control station and the dependent station. . 24. A data transmission method for transmitting and receiving data and control signals to and from a plurality of subordinate stations, and transmitting and receiving data and control signals to and from the control station via wired transmission or wireless transmission. , It is judged whether or not the dependent station is operating depending on whether or not the response signal from the dependent station to the inquiry signal is input within a predetermined time from the transmission of the inquiry signal from the control station to the dependent station. A data transmission method, wherein the number of wireless transmission steps interposed between the control station and the dependent station is determined based on the input time of the reaction signal input within the predetermined time. 25. The data transmission method according to claim 24, wherein the communication method between the control station and the dependent station is changed according to the determined connection state between the control station and the dependent station. . 26. A computer-readable storage medium that stores a program for realizing the data transmission device or data transmission method according to any one of claims 1 to 25 using a computer.