JPH0749820A - Wireless printer buffer - Google Patents

Abstract

(57) [Summary] [Purpose] To ensure high reliability of transmission and to meet the demand for speeding up transmission processing. [Configuration] A printer buffer for temporarily storing print data supplied from the personal computers 10a and 10b in a memory inside the transmission side terminal 1 and then wirelessly transferring the print data to the printer 18 side.
Checks whether the received print data has an error. If an error is detected, if the error correction code is added to the print data and the error is within the correctable range, The print data is corrected, and in other cases, the sender terminal 1 is requested to retransmit the print data. The transmission side terminal 1 has a switch 8 for setting or canceling the error correction function, and when the user operates the switch 8 to set the error correction function, the transmission including the error correction code is performed. Send print data in the format. On the other hand, when the user cancels the setting of the error correction function, the print data is transmitted in the transmission format that does not include the error correction code.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing device such as a personal computer or a word processor (hereinafter referred to as a personal computer).
The present invention relates to a wireless printer buffer for wirelessly transferring print data created by the printer.

[0002]

2. Description of the Related Art With the progress of OA (office automation) and FA (factory automation), a device called a printer buffer has been developed. This printer buffer is placed between multiple personal computers and the printer, and after temporarily holding the print data output from each personal computer in the internal memory, it monitors the operating status of the printer and If you use this printer buffer, you can transfer print data from the personal computer to the memory inside the printer buffer at high speed, so the personal computer can move to the next process quickly without waiting for the end of printing. it can.

Some of the above printer buffers wirelessly connect a personal computer to a printer. This wireless printer buffer temporarily stores print data output from multiple PCs connected via a cable in the internal memory and then sends it as a radio wave to the sending side terminal and the print data that is a radio wave. Is received, detected and demodulated, and the demodulated print data is temporarily stored in an internal memory and then supplied to a printer connected via a cable.
By arranging many wireless printer buffers like this, it is possible to avoid the trouble of laying cables around, so it is not only very easy to add or move PCs and printers, but also multiple printers using multiple PCs. Since the printer can be shared, the printer in use can be avoided, the print data can be supplied to the printer in standby, and the device can be operated efficiently.

[0004]

By the way, there is a situation in which noise from other radio wave radiators is easily mixed in a radio line, and in addition, radio waves are difficult to reach in the case of remote communication or communication with poor visibility. Therefore, in the above-mentioned conventional wireless printer buffer, a function of checking whether or not an error due to circumstances on the wireless line has occurred in the received print data at the receiving side terminal (error detection function ), And if the error is minor, it self-repairs (error correction function), and if the error exceeds the self-repair capability, it has a function of requesting retransmission, which results from the inconvenience of the wireless line situation. , So-called garbled characters are prevented from occurring. Here, in order for the receiving side terminal to effectively exhibit the error detecting function, it is premised that the transmitting side terminal adds an error correction code such as a Hamming code to the print data to be transmitted. .

However, the inter-wireless transmission rate is irrelevant to the addition of the error correction code, and the bandwidth of the communication line and the signal /
The upper limit is determined by the noise ratio. In other words, if the error correction code is added to the print data as long as the wireless transmission rate is set to the upper limit of the permissible range, the print data per unit time is equal to the amount of the error correction code added per unit time. Will be eliminated. Therefore, adding an error correction function is
On the other hand, the reliability of data transmission is remarkably improved, but on the other hand, there is an unfavorable aspect that the effective transmission speed of print data is lowered and the communication time (traffic) is increased.

The present invention has been made under the background described above, and an object thereof is to provide a wireless printer terminal which can meet the demand for speeding up the transmission processing (shortening the communication time).

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 comprises a transmission side terminal to which a data processing device is connected and a reception side terminal to which a printer is connected, A wireless printer buffer for temporarily storing print data supplied from the data processing device in a memory inside the transmission side terminal and then wirelessly transferring it to the printer side, wherein the transmission side terminal has an error correction function. And an operating means for setting or canceling the setting, and when the user operates the operating means to set the error correction function, the print data is transmitted in the transmission format to which the error correction code is added. , When the user operates the above operating means to cancel the setting of the error correction function, the transmission format without adding the error correction code is used. Character transmitting means for transmitting character data, and the receiving terminal has an error checking means for checking whether the received print data has an error on the communication line, and the error checking means. When an error is detected by the inspection means, if the error correction code is added to the print data in which the error is detected and the error is within the range that can be corrected based on the error correction code, the print Correct the data, in other cases,
It is characterized in that it comprises a receiving side control means for requesting the transmission side terminal to retransmit the print data.

[0008]

According to the structure of the present invention, whether or not the print data is transmitted to the receiving side in the transmission format with the error correction code added can be arbitrarily selected by the user by operating the operating means. . Therefore, the user operates the above-mentioned operation means when there is almost no fear that a data error occurs on the wireless line because the communication distance is extremely short and there is no obstacle to noise. The correction function setting can be canceled. This reduces the effective transmission speed of print data and communication time (traffic).
Can be prevented from increasing. On the other hand, if there is a fear that a data error may occur due to telecommunications, poor visibility, or a large number of radio wave radiators in the vicinity,
The user can operate the operation means to set the error correction function. As a result, high reliability for transmission can be ensured.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an electrical configuration of a printing system using a wireless printer buffer according to an embodiment of the present invention. The wireless printer buffer includes one transmission side terminal 1 and one transmission side terminal 1. It is composed of the receiving side terminal 2 of the table. Further, FIG. 2 is a front view showing a mechanical appearance configuration of the transmission side terminal 1. The external appearance of the front surface of the reception-side terminal 2 is the same as that of the transmission-side terminal 1, and therefore its illustration is omitted.

In FIG. 1, the transmission side terminal 1
Is an interface circuit based on the Centronics specification3.
4, CPU (central processing unit) 5, memory 6, display 7,
It is composed of a switch 8 and a transmission circuit 9. A personal computer 1 is connected to the interface circuits 3 and 4 via a cable.
0a and 10b are connected and the print data output by the personal computers 10a and 10b are supplied to the CPU 5.

The CPU 5 controls each part of the apparatus by executing the processing program stored in the ROM constituting the memory 6 using the work RAM also constituting the memory 6. That is, the CPU 5 adds an identification code indicating the output source to the captured print data so that the print data supplied from the respective output sources via the interface circuits 3 and 4 are not mixed. Then, after the print data to which the identification code is added is once stored in the data RAM which also constitutes the memory 6, the print data stored in the data RAM is sequentially supplied to the transmission circuit 9 at a predetermined timing.

At this time, the CPU 5 looks at the error correction function presence / absence flag set in the EEPROM which also constitutes the memory 6, and when the content of this flag indicates [1], the error correction code ( In this example, print data is supplied to the transmission circuit 9 in a transmission format with a Hamming code) added. On the other hand, when the content of the flag indicates [0], the print data is supplied to the transmission circuit 9 in the normal transmission format without adding the error correction code. These operations are performed by multitask processing.

As described above, the memory 6 temporarily stores print data transferred from the personal computers 10a and 10b via the ROM storing the processing program, the work RAM in which the work area of the CPU 5 is set, and the interface circuits 3 and 4. Large-capacity data RAM (about 1MB) to be retained, and I
It is composed of a rewritable EEPROM or the like in which various setting contents such as D number, device number, presence or absence of error correction function are stored.

As shown in FIG. 2, the display 7 has four 7
It is composed of segment LED display elements, and displays various setting states and operating states of the transmitting side terminal 2. The switch 8 has a power switch 8a, as shown in FIG.
It is composed of a buffer switch 8b and a select switch 8c which are used respectively when switching various functions such as switching the presence or absence of an error correction function, and when changing setting contents and display contents.

Further, the transmission circuit 9 is controlled by the CPU 5 and applies modulation by print data to the transmission carrier of 1200 MHz band. Then, the transmission carrier modulated by the print data is transmitted to the reception-side terminal 2 of the transmission destination via the antenna 9a under the wireless data transmission rate condition of 32 Kbps.

On the other hand, the receiving side terminal 2 comprises interface circuits 11 and 12, a receiving circuit 13, a CPU 14, a memory 15, a display 16 and a switch 17. A personal computer 10c is connected to the interface circuit 11 similarly to the transmission side terminal 1, and a printer 18 is connected to the other interface circuit 12 via a cable. The reception circuit 13 receives the radio wave (transmission carrier modulated by print data) radiated from the antenna 9a of the transmission side terminal 1 by the antenna 13a.
It is received via a, detected, and demodulated into print data.
After digitizing the demodulated print data, C
Supply to PU14.

The CPU 14 is an RO that constitutes the memory 15.
By executing the processing program stored in M using the work RAM which also constitutes the memory 15, each unit of the apparatus is controlled. That is, the CPU 14 controls the receiving circuit 1
Personal computer 10 via the interface circuit 11 and the print data transmitted from the terminal 1 on the transmitting side via
The print data transferred from c is temporarily stored in the data RAM forming the memory 15, and the print data temporarily stored in the data RAM is monitored via the interface circuit 12 while monitoring the operating state of the printer 18. 18 is sequentially supplied to perform printing.

A more detailed data processing procedure of the CPU 14 will be described with reference to FIG. As shown in FIG.
Captures the received print data (step SP
1) The received print data is inspected by the method of cyclic redundancy check (CRC) to determine whether there is a data error on the wireless line (step SP2). If no data error is found as a result of this inspection, the fetched print data is temporarily stored in the data RAM (step SP
6). On the other hand, as a result of the inspection (step SP2), if a data error is detected, it is checked whether or not the error correction code is added to the print data in which the error is detected (step SP3), and the error correction code is added. If not, it requests the terminal 1 on the sending side to retransmit the print data (step SP7). On the other hand, if the error correction code is added (step SP3), it is determined whether or not the error is within the correctable range based on the error correction code (step SP4). If it is determined that the error is within the correctable range, Correction is performed based on the error correction code (step SP5), and the corrected print data is temporarily stored in the data RAM (step SP6). On the other hand, if it is determined that the error cannot be corrected, the transmission side terminal 1 is requested to retransmit the print data (step SP7). Note that C
The PU 14 not only executes the data processing shown in FIG. 3, but also monitors the operating state of the printer 18 for the print data temporarily stored in the data RAM, and the interface circuit 1
2 to the printer 18 sequentially. These operations are performed by multitask processing.

As described above, the memory 15 is supplied from the personal computers 10a, 10b, 10c via the ROM for storing the processing program, the work RAM in which the work area of the CPU 14 is set, the receiving circuit 13, and the interface circuit 11. It is composed of a large-capacity data RAM (about 1 MB) for temporarily holding print data, a rewritable EEPROM for storing various setting items such as an ID number and a device number, and the like.

Like the display 7 of the transmission side terminal 1, the display 16 is composed of four 7-segment LED display elements and displays various setting states and operating conditions of the reception side terminal 2. The switch 17, like the switch 8 of the transmission side terminal 1, includes a power switch, a buffer switch used for switching various functions, changing setting contents and display contents, and a select switch. Has been done.

Next, the procedure for setting the error correction function of this example will be described with reference to FIG. As a premise,
Currently, the error correction function presence / absence flag set in the EEPROM of the memory 6 is reset to [0] (indicating that the error correction function is canceled).

Change of operation mode When the power switch 8a is pressed while pressing the select switch 8c of the transmission side terminal 1, the setting mode is set. From this, the CPU 5 causes the setting items of page 1 (see FIG.
As shown in FIG. 5A, “PG-1” is displayed on the display 7 to notify that page 1 is selected.

Page selection When the buffer switch 8b is pressed once while "PG-1" is displayed on the display 7, the CPU 5 shifts to the setting item of page 2 (see FIG. 4) and The display in the display column at the bottom digit of the display 7 is changed to "2" to inform that the page 2 is selected. "PG
If the buffer switch 8b is pressed once again while "-2" is displayed, the setting item of the page 3 (the same figure) is set and the display column of the last digit of the display 7 is displayed. To indicate that page 3 is selected.

Item Selection Next, when the select switch 8c is pressed once in the state where "PG-3" is displayed on the display 7, the CPU 5 shifts to the setting of the presence or absence of the error correction function, and FIG. As shown in b), "3.E-0" is displayed on the display 7 to inform that the page 3 is selected by the display "3." in the display column of the highest digit, and the third digit and The display "E-" in the second digit display column indicates that the error correction function has been set or canceled, and the display "0" in the last digit display column indicates that the error correction function has been released. ,further,
By blinking the display in the display column at the bottom digit, it is informed that the number in this part can be changed. In addition,
In this example, when the display device 7 displays "3.E-0" and the select switch 8c is pressed once,
The process proceeds to the destination restriction setting (Fig. 4).

Setting of Error Correction Function Next, when the buffer switch 8b is pressed once while the display 7 displays "3.E-0", the CPU 5
The error correction function presence / absence flag set in the EEPROM is indicated (indicating that the error correction function is set).
While setting to [1], as shown in FIG.
Change the display in the last column of the display unit 7 to "1",
Notifies that the error correction function has been set. After that, when the power is turned off and only the power switch is pressed again, the operation is performed in the operation mode to which the error correction function is added.

The procedure for canceling the setting of the error correction function is also the same as the above. That is, when the buffer switch 8b is pressed once in the above-mentioned scene where "3.E-1" is displayed on the display 7, the CPU
Reference numeral 5 resets the error correction function presence / absence flag set in the EEPROM to [0] (indicating that the error correction function is canceled) and displays the display column in the last digit of the display unit 7. Is changed to "0" to notify that the error correction function has been canceled. After this, once turn off the power,
If only the power switch is pressed without pressing the select switch 8c again, the operation is performed in the operation mode in which the error correction function is canceled.

According to the above configuration, the user determines whether or not the print data is transmitted in the transmission format including the error correction code by the buffer switch 8b and the select switch 8.
It can be arbitrarily determined by operating c.
Therefore, the user has an extremely short communication distance and
If there is almost no fear of data error on the wireless line because other radio wave radiators are not nearby,
The buffer switch 8b and the select switch 8c can be operated to cancel the setting of the error correction function. As a result, it is possible to prevent the effective transmission speed of print data from decreasing and the communication time (traffic) from increasing.

On the other hand, if there is a fear that a data error may occur due to telecommunications, poor visibility, or a large number of radio wave radiators in the neighboring area, the user may select the buffer switch 8b and the select switch 8c. By operating
The error correction function can be set. Thereby, high transmission reliability can be ensured.

The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific structure is not limited to this embodiment, and the design change and the like without departing from the gist of the present invention. Even this is included in this invention. For example, the error detection method is not limited to the cyclic redundancy check (CRC), but may be another method, for example, an odd check, and the error correction code is not limited to the Hamming code, and may be another code, for example, a BCH code.

[0030]

As described above, according to the wireless printer buffer of the present invention, the user determines whether or not the print data is transmitted to the receiving side in the transmission format including the error correction code. It can be freely selected by operating the operating means. Therefore, the user operates the above-mentioned operation means when there is almost no fear that a data error occurs on the wireless line because the communication distance is extremely short and there is no obstacle to noise. The correction function setting can be canceled. This reduces the effective transmission speed of print data and communication time (traffic).
Can be prevented from increasing.

On the other hand, if there is a fear that a data error may occur due to remote communication, poor visibility, or a large number of radio wave radiators in the vicinity, the user operates the above operating means. The error correction function can be set. As a result, high reliability for transmission can be ensured.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a printing system using a wireless printer buffer according to an embodiment of the present invention.

FIG. 2 is a front view showing a mechanical external configuration of a transmission-side terminal that constitutes the wireless printer buffer.

FIG. 3 is a flowchart showing a processing procedure performed by a CPU of a receiving side terminal.

FIG. 4 is a diagram provided for explaining an error correction function setting procedure and a cancellation procedure of this example.

FIG. 5 is a diagram provided for explaining a setting procedure and a releasing procedure of the error correction function.

[Explanation of symbols]

 1 Sending Terminal 2 Receiving Terminal 3 Interface Circuit 5 CPU (Sending Side Control Means) 6 Memory 8 Switch (Operating Means) 8b Buffer Switch 8c Select Switch 9 Sending Circuits 10a, 10b Personal Computer (Data Processing Device) 13 Receiving Circuit 14 CPU (Error checking means, receiving side control means) 18 Printer

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Claims (1)

[Claims] 1. A transmission side terminal to which a data processing device is connected and a reception side terminal to which a printer is connected, and print data supplied from the data processing device is temporarily stored in a memory inside the transmission side terminal. A wireless printer buffer for wirelessly transferring to the printer side after storing, wherein the transmitting side terminal is an operating means for setting or canceling an error correction function, and a user operates the operating means. When the error correction function is set by operation, the print data is transmitted in the transmission format to which the error correction code is added, while the user operates the operation means to cancel the setting of the error correction function. And a transmission side control means for transmitting print data in a transmission format without adding an error correction code, and The receiving side terminal has an error checking means for checking whether or not there is an error on the communication line in the received print data, and when an error is detected by the error checking means, the print data in which the error is detected is If the error correction code is added and the error is within a range that can be corrected based on the error correction code, the print data is corrected. In other cases, the transmission side terminal is corrected. A wireless printer characterized by further comprising: a receiving side control means for requesting retransmission of the print data.
buffer.