JPH07111695B2 - Data transfer method, data transmission device and restoration device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for wirelessly transferring data, and more specifically, to a method of transferring data between computers or between a computer and peripheral devices, and a data transmitting apparatus and a data restoring apparatus to which this method can be applied. Regarding

[0002]

2. Description of the Related Art Generally, when transferring data between computers or peripheral devices, the two are usually connected by a cable and transferred by wire. With the spread of data, wireless data transfer has been attempted without the need to connect a cable. In addition, there is an increasing demand for sharing high-speed devices such as laser printers among multiple computers to collectively process print data and the like, and dislike complicated wiring arrangements and attempt to transfer data wirelessly. Things are also proposed.

[0003]

However, since the wireless data transfer is essentially serial communication, the data transfer speed is slow, and it takes a long time to transfer the data, which is a serious obstacle to the actual use. It was For example, if you try to transfer print data from a computer to a printer wirelessly, a specific low-power wireless, which is open to general use, can achieve a transfer speed of only several thousand bps (bit per second), and a direct connection via a cable. A fraction of the standard Centronis standard 8-bit parallel transfer
Only a tenth performance is obtained.

Further, since the computer is occupied during the data transfer, the use efficiency of the computer is also reduced. Furthermore, when a laser printer or the like is shared by a plurality of computers, it takes a long time to transfer data and the laser printer is in a congested state. There is also the problem of deterioration.

It is possible to increase the frequency band to be used or change the modulation method in order to increase the speed of data transfer by radio, but in a specific low power radio station released for general use, the frequency is fixed. Since the upper limit is set for the communication speed of data wireless for the purpose of data transfer (4800 bps at 400 MHz, 1.2 G
It is virtually impossible to improve the transfer rate by changing the used frequency. On the other hand, although a method of compressing data and then transferring the data is also proposed, the compression rate is at most about 1/2, and it takes a lot of time and effort to compress and decompress the data. is not.

A data transfer method, a data transmission device, and a restoration device of the present invention have been made for the purpose of solving these problems and improving the speed of data transfer between computers or peripheral devices. I took it.

[0007]

According to the data transfer method of the present invention for transferring data between computers or peripheral devices, the transmitting side converts output data into a plurality of packets to which management information of the data is added. The packet is divided and the plurality of packets are respectively output via a plurality of channels by wireless communication. The receiving side receives a plurality of packets via the plurality of channels, and data and management information are received from the received packet. Is extracted, and the extracted data is assembled in the original order based on the management information.

The data transmission apparatus of the present invention is applicable to the above-mentioned data transfer method and wirelessly transmits data to a computer or a peripheral device. Data to be output is added with management information of the data. Data dividing means for dividing into a plurality of packets, an empty channel is selected from a plurality of channels, a plurality of outputting means for outputting data wirelessly by using the channels, and a usage status of the plurality of transmitting means are judged, The gist of the present invention is to provide an output control unit that sequentially outputs the divided packets by a plurality of output units.

On the other hand, the data restoration device of the present invention is applicable to the above-mentioned data transfer method and restores data wirelessly transmitted to a computer or a peripheral device. A plurality of receiving means for receiving the transmitted packet, a data separating means for separating the data and its management information from the received packet, and the separated data based on the management information. The gist is that the data assembling means for assembling is arranged.

The data transfer method of the present invention comprises:
The management information may include an error detection code or an error correction code, and the length of the data included in each packet may be changed according to the packet transmission / reception status such as the error occurrence frequency. Absent. The wireless in the present invention means that it is not a wired system directly connected by a cable, and it is not limited to specific low power communication, and may be specific weak communication or communication using other bands.
Optical communication using infrared rays, far infrared rays, microwaves, or the like can also be used.

[0011]

In the data transfer method of the present invention configured as described above, the receiving side divides the data to be output into packets to which the management information of the data is added, and this is divided via a plurality of channels. Output wirelessly. The receiving side receives this packet, extracts data and management information from the packet, and assembles the data in the original order based on this management information. Therefore, the data is once broken into packets and transferred by a plurality of channels as if they were transferred in parallel.

On the other hand, the data transmitting apparatus of the present invention can realize the transmitting side of this transfer method, and the data restoring apparatus of the present invention can realize the receiving side of this transfer method. The data transmission device and the data restoration device are usually used in a pair, but for example, data corresponding to "transfer order free" is previously determined as one of the management information, and if this data is not listed, the data transfer order is set. If it is determined that is fixed, it is also possible to perform data transfer between a transmitting device and a restoring device in which one or both do not have management information. In the present invention, the management information may further include an error detection code or an error correction code, and the length of the data included in each packet may be changed according to the transmission / reception status of the packet such as the error occurrence frequency. It is desirable to improve the transfer speed and ensure the reliability of data transfer at the same time.

[0013]

Preferred embodiments of the present invention will be described below in order to further clarify the structure and operation of the present invention described above. FIG. 1 is a schematic configuration diagram of a data transmission device 1 and a data restoration device 5 as an embodiment of the present invention, and FIG. 2 is a block diagram showing an internal configuration of the data transmission device 1. As shown, the data transmission device 1 is used by being connected to the printing output of the computer 2, and the data restoration device 5 is used.
Is used by connecting to the print input of the printer 6.

As shown in FIG. 1, the data transmission device 1 and the data restoration device 5 mainly include a data communication control unit 7, a plurality of radio communication control units 8 and an antenna 9. In this embodiment, since data is sent from the computer 2 to the printer 6 via the data transmission device 1 and the data restoration device 5, the data transmission device 1 functions as a master and the data restoration device 5 functions as a slave. The data transmission device 1 and the data restoration device 5 have the same internal configuration, and data can be transferred from the data restoration device 5 to the data transmission device 1. Also in this embodiment, data is sent from the data restoration device 5 to the data transmission device 1 in order to make the data length variable. The actual data transfer will be described later.

The internal structure of the data transmitter 1 will be described. As shown in FIG. 2, the data transmission device 1 includes an 8-bit microprocessor 11, eight SIOs 12 for converting data output from the microprocessor 11 into a serial signal, and transmissions connected to each of the SIOs 12. The memory controller 20, the IO decode circuit 22, the transmission unit controller 25, and the like are connected to the data bus 16, the address bus 17, and the like of the microprocessor 11 and the like. Also,
Data input / output of the memory 27 is also connected to the data bus 16. The microprocessor 11, the memory controller 20, the IO decoding circuit 22, the transmission unit controller 25, and the memory 27 constitute the data communication control unit 7. Further, the SIO 12 and the transmission unit 14 form the wireless communication control unit 8.

The data transmitting apparatus 1 includes a cable 29,
It is connected to the printing output port 32 of the computer 2 via the connector 30. The microprocessor 11 of the data transmission device 1 controls the data transfer control signals (strobe STRB, reception response ACK, busy BUSY).
Print data is received using the memory controller 2
This print data is sequentially stored in the memory 27 by using 0. When the print data of a predetermined amount or more is stored, the microprocessor 11 forms this data into a packet and sends this to one of the plurality of SIOs 12. At the same time, by controlling the transmission unit controller 25, the transmission unit 1 corresponding to the SIO 12 that has sent the print data
4 is switched to the transmittable state.

Upon receiving the print data, the SIO 12 converts the print data sent as a parallel signal into a serial signal and outputs the serial signal to the transmission unit 14. The communication method is character synchronous (BISYNC synchronous) communication, and SIO12
Outputs a data to be communicated with a synchronization character. The transmission unit 14 puts this serial signal on the frequency of the channel that is assigned in advance, and
From the outside. In this embodiment, eight SIOs 12 and eight transmission units 14 are provided, and each transmission unit 14 can use up to 10 channels. In FIG. 1, each channel is shown by frequencies f1 to fn. Data exchange between the SIO 12 and the microprocessor 11 is performed using the transmission interrupt Tx and the reception interrupt Rx.

The transmission unit 14 includes a specific low power radio station 4
It complies with the standard of the radio equipment for data transmission of 00 MHz band, the communication system is simplex system, the total number of used channels is 10, the modulation system is binary FSK modulation system, and the modulation speed is 48.
It is 00 bps. The eight transmission units 14 in this embodiment have the same configuration, perform carrier sense under the control of the transmission unit controller 25, and perform transmission using a channel in which interference does not occur according to the instruction.

The data restoration device 5 having the same configuration as the data transmission device 1 receives the packet by each transmission unit 14 and outputs it to the microprocessor 11 via the SIO 12. The microprocessor 11 receives the reception interrupt Rx, accesses the SIO 12, reads the received data, and sequentially stores the data in the memory 27.
Then, the data configured on the memory 27 is transferred to the printer 6
To print and print.

Next, the transmission / reception processing executed by the data transmitting apparatus 1 and the data restoring apparatus 5 will be described with reference to the flowchart of FIG. When the print data is sent from the computer 2, the microprocessor 11 of the data transmission device 1 activates the transmission processing routine shown in FIG. 3, and first determines whether or not the connection with the partner station is completed. Perform (step S100).

When it is determined that the connection is not completed, the process of connecting to the partner station is performed (step S12).
0). Data transmission device 1 that attempts to transmit data
The transmitting unit 14 of 1 is called a calling station, and the transmitting unit 14 of the data restoration device 5 that receives data from the calling station is called a called station. An example of a line connection procedure between both stations is shown in FIG.
FIG. 4 shows a procedure in the case of simplex system and fixed / manual channel switching. As illustrated, the calling station transmits a connection request signal including a call name which is a channel number as a control signal after calling and carrier sense. The called station receiving this control signal carries out carrier sensing and then returns a signal which is a connection response signal, whereby the line is connected.

If the connection with the partner station is completed (step S100), the process of storing the data sent from the computer 2 in the memory 27 is performed (step S12).
0). In this case, the data storage location is sequentially performed from an address previously determined as the print data storage location, and the value of the pointer indicating the storage address is incremented by one each time the data is stored. Therefore,
When the data transmission from the computer 2 is continued, the print data is sequentially stored in the memory 27.

After storing the data, the microprocessor 11 determines whether or not the stored data is in a packet (step S130). Since data is transmitted in the form of packets, the microprocessor 11 is waiting for the data sufficient to form the packets to be stored in the memory 27. Also, the routine directly exits to "NEXT" without performing any operation.

When it is determined that sufficient data to form a packet is stored in the memory 27 (step S130), a packet number and an error correction code are added to this data to form a packet. (Step S140). For example, as shown in FIG. 5, the packet P1 is formed by adding the management information PD1 indicating the packet number and the data length and the error correction code HC1 before and after the predetermined number of bytes of data D1. Various types of error correction codes HC1 are known, but in this embodiment,
It is defined as 63 codes represented by coefficients of a predetermined polynomial or a remainder polynomial.

After constructing the packet, which transmitting unit 14 transmits this packet is designated (step S150). Further, together with the number of the transmission unit 14, the start address and end address of the data that forms the packet,
After creating a table of transmission address pointers and the like for this packet and performing processing for canceling the transmission interrupt mask (step S160), the process exits to "NEXT" and this routine is terminated.

When the above processing is performed and the packet is prepared, the transmission interrupt mask is also released. Therefore, the microprocessor 11 receives the transmission interrupt Tx from the SIO 12, and the transmission interrupt shown in FIG. Execute a processing routine. In this interrupt processing, first, the SIO 12 that issued the interrupt request.
Is performed and the packet number assigned to the SIO 12 is specified by referring to the table (step S200). Then, it is determined whether or not there is transmission data remaining (step S210). If transmission of all data of the packet is completed, the process directly returns to end this routine.

If the packet transmission data remains, a process of referring to the transmission address pointer to read 1-byte data from the memory 27 is performed (step S).
220). When 1 byte of data is read, the above-mentioned address pointer is automatically incremented, and the microprocessor 11 prepares for the next transmission interrupt Tx. The data read from the memory 27 is output to the SIO 12 (step S230), and by the transmission unit 14,
It is transmitted to the data restoration device 5 via a predetermined channel.

When a large amount of print data is sent from the computer 2 by repeating the above processing (FIGS. 3 and 6), the microprocessor 11 cuts this data into a predetermined length and packetizes it. Go on. The constructed packets are sequentially transmitted to the SIO 12 and the transmission unit 14.
However, since the data from the computer 2 is transferred in parallel, the transfer speed thereof is several times to several tens of times that of the transmission unit 14. Therefore, before the transmission of one packet is completed, the next packet is constructed. In this case, the next packet will be transmitted by the SIO 12 and the transmission unit 14 different from the previous packet. The transmission channel in that case is naturally different.

FIG. 7 shows how the print data transferred from the computer 2 is divided into a plurality of packets and transmitted on different channels. The data transferred from the computer 2 and stored in the memory 27 is divided into data D1, D2 ... Of a certain data length, and management information and error correction code are added to form packets P1, P2. After that, the SIO1 that is not used sequentially from the packet P1
2, assigned to the transmission unit 14 and transmitted via the empty channels f1, f2, .... In the example shown in FIG. 7, since the difference between the data transfer speed from the computer 2 and the wireless data transmission speed is not so large, the use of three channels is shown as sufficient.
If the difference in transfer speed is large, it is possible to use more channels.

The data transmission by the transmission unit 14 is limited to 40 seconds or less, as indicated by "communication" in FIG. This is because the frequency band used in the present embodiment is open, so that a certain transmission unit 14 limits the time during which it can occupy one channel and uses it for another wireless station that intends to use the channel. Is given the opportunity. The pause time of transmission is defined to be 2 seconds or more, and if another wireless station does not use this channel during this period, the next communication can be started. As a result, between the data transmitting device 1 and the data restoring device 5, as shown in FIG. 8, a section A in which communication is performed (maximum 40 seconds) and a section B in which communication is not performed (minimum 2 seconds). Communication is performed in the form of repeating.

Next, the processing on the data restoration device 5 side will be described. Transmission unit 14 of the data restoration device 5, SI
Upon receiving the data via the predetermined channel, the O12 outputs the reception interrupt Rx to the microprocessor 11. Upon receipt of this reception interrupt Rx, the microprocessor 11 activates the reception processing interrupt routine shown in FIG.
First, it is determined whether or not the received data is data indicating the beginning of a packet (step S300).

When it is judged that the packet starts,
Information on the packet number and the data length is extracted from the data (step S310), and the memory 27 of the data restoration device 5 is extracted.
An area necessary for receiving data from the packet is secured above, and a process of updating the memory table is performed (step S320). Since the data length can be known from the management information added to the head of the packet, it is easy to secure an area of the required number of bytes on the memory 27. The memory table is a table that stores which packet number data is expanded in which area. When receiving a new packet in order to receive data of a plurality of packets in parallel, This table is updated.

Data that can be output to the printer 6 and printed is present in the memory 27 after the processing more than necessary for starting the reception of a new packet or after the processing of data reception described later. Whether or not to do so is determined (step S330). Since the data is transmitted in units of packets, the data is not always transmitted from the beginning of the entire data when the communication via a certain channel fails. Further, since the management information at the beginning of the packet and the error correction code at the end are also sent, just because the reception interrupt Rx is received does not necessarily mean that data that can be printed at all times exists in the memory 27. Therefore, it is determined whether or not there is printable data, and if there is data, the data is output to the printer 6 and the output pointer is updated (step S340).

If the data received by the transmitting unit 14 or SIO 12 and causing the reception interrupt Rx does not indicate the start of the packet (step S300), it is determined whether or not the data indicates the end of the packet. (Step S350). When it is determined that the data indicates the end of the packet, the error correction code HC already received is checked (step S360).
Data D and error correction code HC expanded on the memory 27
Is checked to determine whether or not there is an error (step S370), and if there is no error, the print data is printed as it is (step S370).
330, 340).

When it is determined that the received data has an error (step S370), the data restoration device 5
Performs a process of transmitting predetermined data and requesting retransmission of the data (step S380). Through this processing, the data transmission device 1 retransmits the packet that has been transmitted. In this embodiment, the function of requesting data retransmission is provided for each channel, but it is also possible to provide only some of the plurality of channels with the retransmission function and to make other channels dedicated to reception. When a data error is detected, a retransmission request is issued using a specific channel to retransmit the data. Since it takes a predetermined time to switch the direction of data transmission / reception, when an error occurs more than a certain frequency, the efficiency of data transfer as a whole is improved by specifying the channel to be retransmitted.

When it is determined in steps S300 and S350 that the received data is neither the beginning nor the end of the packet, that is, the data D in the packet, 1 byte received from the SIO 12 is received. Processing for reading the data of (step S39)
0). The 1-byte data thus read is expanded in a predetermined area of the memory 27 based on the memory table (step S400). The manner in which the data transmitting device 1 forms the data in the memory 27 into packets has been described above with reference to FIG. 7, but the data restoring device 5 conversely expands the data read from the packets in the memory 27. . Since data communication is performed simultaneously using a plurality of channels, the received data is expanded into an address determined according to the packet number by referring to the memory table.

By performing the above-described processing, the data transmitted from the data transmission device 1 into a plurality of packets and transmitted through a plurality of channels are sequentially expanded in a predetermined area on the memory 27. When it is developed into a printable state, it is sequentially output to the printer 6. Since the packet number and data length are added to each packet,
The print data can be output even if the reception of the packet is not completed, but an error may be found after the transmission. Therefore, it is possible to start the printing after the reception of all the data of the packet is completed.

In the present embodiment, since the print data of the computer 2 is wirelessly transmitted to the printer 6, the computer 2 and the printer 6 can be freely arranged without any troublesome connection work. Moreover, since the data transfer performed in units of packets is performed in parallel using the plurality of SIOs 12 and the transmission units 14, the transfer speed is extremely high, and the problem of low transfer speed in wireless data transfer is solved. is doing. Further, since the error correction code is added in packet units, high reliability is achieved in data transfer. In addition, while another packet is being retransmitted while an error packet is being retransmitted, the transfer of another packet can be executed, so that the overall transfer efficiency can be improved.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and it is needless to say that the present invention can be implemented in various modes without departing from the scope of the present invention. Is. For example, the frequency of errors in packet transmission is detected, and if the frequency of errors is high, the length of the data contained in the packet is shortened to prevent a decrease in transfer efficiency due to data retransmission due to the occurrence of an error. It can also be configured to. Further, when the frequency of error occurrence is low, the length of the data included in the packet can be increased to improve the transfer efficiency.

In addition, a configuration using a band of 1.2 GHz as the transmission frequency of the transmission unit 14, a configuration applied to communication between computers, a configuration applied to a LAN (local network) including a plurality of computers and printers Various configurations such as a configuration in which the number of used channels is determined according to the total amount of data to be transmitted can be considered. Further, the data transmitting apparatus of the present invention is usually used in combination with the data restoring apparatus of the present invention, but if the order of the data transmission channel and the packet is fixed, the data receiving apparatus cannot recognize the packet management information. It can also be received by the device. Similarly, it is also possible to use a combination of a data transmission device that does not add packet management information and the data restoration device of the present invention.

[0041]

As described above, the data transfer method of the present invention has an excellent effect that data can be transferred wirelessly at high speed between computers or a peripheral device such as a printer. Therefore, each device such as a computer can be freely arranged. Moreover, since the data transferred in parallel is in units of packets, and the management information is added to this, there is no restriction on the transfer order of the packets, and high-speed data transfer can be easily performed.

The data transmission device and the data restoration device using this data transfer method can be realized with an extremely simple structure, and high-speed data transmission and restoration can be realized respectively.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a data transmission device 1 and a data restoration device 5 according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of the data transmission device 1.

FIG. 3 is a flowchart showing a transmission processing routine performed by the data transmission device 1.

FIG. 4 is an explanatory diagram showing an overall control up to data communication between two wireless stations.

FIG. 5 is an explanatory diagram showing a configuration example of a packet.

FIG. 6 is a flowchart showing a transmission interrupt processing routine executed by the data transmission device 1.

FIG. 7 is an explanatory diagram showing how print data is divided into a plurality of packets and how data of a plurality of packets is reconstructed.

FIG. 8 is an explanatory diagram showing a relationship between data communication and a transmission suspension period between wireless stations.

FIG. 9 is a flowchart showing a reception processing interrupt routine executed by the data restoration device 5.

[Explanation of symbols]

 1 Data Transmission Device 2 Computer 5 Data Restoration Device 6 Printer 7 Data Communication Control Unit 8 Wireless Communication Control Unit 9 Antenna 11 Microprocessor 12 SIO 14 Transmission Unit 16 Data Bus 17 Address Bus 20 Memory Controller 22 IO Decoding Circuit 25 Transmission Unit Controller 27 memory

Claims (4)

[Claims] 1. A data transfer method for transferring data between computers or a peripheral device, wherein the transmitting side divides output data into a plurality of packets to which management information of the data is added, The respective packets are output via a plurality of channels by wireless communication, the receiving side receives the plurality of packets via the plurality of channels, and extracts data and management information from the received packets, A data transfer method, characterized in that the extracted data is assembled in the original order based on the management information. 2. A data transmission device for wirelessly transmitting data to a computer or a peripheral device, comprising: a data dividing means for dividing output data into packets to which management information of the data is added; An output that selects a channel, determines a plurality of output means for wirelessly outputting data using the channel, and the use statuses of the plurality of transmission means, and sequentially outputs the divided packets by the plurality of output means A data transmission device comprising a control means. 3. A data recovery device for recovering data wirelessly transmitted to a computer or a peripheral device, comprising: a plurality of receiving means for receiving a packet transmitted through one of a plurality of channels; A data decompression device comprising a data separating means for separating data and its management information from the packet, and a data assembling means for assembling the separated data into the original arrangement based on the management information. 4. The data transfer method according to claim 1, wherein the management information includes an error detection code or an error correction code, and the length of the data included in each packet includes an error occurrence frequency and the like. A data transfer method that varies depending on the status of packet transmission and reception.