JPH11129554A - Print data checking system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a print data checking system in which various processing including retransmission of print data can be performed actively on the print data receiving side based on the check results of received print data. SOLUTION: A printer 4 receives a print data through a print board 3 and operates the check sum of received print data which is then stored in a register 46. The print board 3 comprises an I/O control section 31 for receiving a print data from the transmitting side and delivering an internal state, a centrodata I/O section 34 performing bidirectional communication with the printer 4, a section 36 for operating the check sum of a received data, and a section 37 for comparing a check sum value stored in the register 46 with the check sum value at the operating section 36. According to the system, abnormal occurrence of a check sum value in the check storing register register 46 can be detected and notified to at least one of the printer or the print data transmitting side and a specified retry processing can be carried out actively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print data check method for checking when print data received by a printer device is received, and more particularly, to resend print data based on a check result of received print data. The present invention relates to a print data check method capable of performing various processes including a printing process.

[0002]

2. Description of the Related Art Conventionally, in this type of print data check system, there is a technology described in, for example, Japanese Patent Application Laid-Open No. 1-241478. This printing apparatus (printer apparatus) will be described with reference to FIGS.

[0003] As shown in FIG.
0 indicates that the host computer 10
The print data is received from 0 and stored. Printer device 20
The zero control unit 202 has a central processing unit (CPU), a read-only memory (ROM), and a random access memory (RAM), and controls the entire printer device 200.

A checksum storage unit 203 connected to the control unit 202 stores the total print data. Control unit 202
The pattern conversion unit 204 connected to the .converts the character code into a corresponding pattern. Frame buffer 205
Receives print data in which a pattern has been developed from the control unit 202, and the print data is printed out by the dot printer 206.

[0005] The printer display unit 207 is a printer
The control unit 202 receives and displays the data abnormality notification received by the control unit 202.

FIG. 6 shows an example in which the data transmitted from the host computer 1 shown in FIG. 1 is mixed with noise and added by 1 bit, so that the value of the checksum is different and an abnormality in the data is found. FIG. 6 shows a carriage return ([c
r]) and form feed ([ff]) are displayed, and the character control code A (hex data 41H) sent from the host computer 100 is replaced with the character control code C
(Hexa data 43H), the example shows that the checksum changes from "100" to "102".

In this example, the host computer 1
00 is transmitted from the form feed ([f
f]) The checksum correction value is always placed after the instruction code, and the lower two digits of this checksum are always corrected to “00”.

Next, the processing of the printer will be described with reference to the flowchart of FIG. Printer device 2
In 00, the CPU of the control unit 202 makes full use of the RAM in accordance with the control program stored in the ROM to advance the processing.

First, data sent from the host computer 100 is received and stored by the input buffer 201 (step S101). The control unit 202 reads the data stored in the input buffer 201 one by one (step S10).
2) It is checked whether the read data is a page break code (step S103).

If step S103 is "NO" and the page break code is not found, the control section 202 uses the pattern conversion section 204 to develop the code into a pattern on the frame buffer 205 (step S104) and checks the received data for a checksum. The data is added to the storage unit 203 (procedure S105), and the process returns to step S102 for reading the next one data.
This processing is repeated until a page break code is received at S ".

If the above step S103 is "YES" and the page break code is set, the control section 202 adds the received data to the checksum storage section 203 (step S111) and reads the checksum correction value of the next data (step S111). Step S112). Next, the control unit 202 obtains a checksum by adding the correction value data to the checksum storage unit 203 (step S113), and checks the checksum value (step S114).

If step S114 is "YES" and the checksum value is "00" (Null), the control unit 202 drives the dot printer 206 to perform printing output processing (step S115).

On the other hand, if the step S114 is “NO” and the checksum value is not “00” (Null), the control unit 202 displays an error on the printer display unit 207 (step S116) and does not perform the printing process. End the procedure.

[0014]

According to the above-described conventional print data check method, if the received data is abnormal, the printer device can detect this abnormality, display an error, and stop printing. Notifying the source of the data or requesting retransmission of normal data,
There is a problem that the active operation cannot be performed on the print data receiving side.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a print data receiving side capable of actively performing various processes including retransmission of the print data based on a check result of the received print data. It is to provide a check method.

[0016]

A print data check method according to the present invention is a print data check method for checking when print data received by a printer apparatus is received. The printer device receives the print data via the printer board, calculates and stores a checksum of the received print data, and stores the checksum value stored in response to a checksum request. While returning the print data to the printer board and printing out the print data received when receiving the print permission from the printer board, the printer board sends the received print data to the printer device and checksums the print data. At the time of printout, requesting the printer device to receive a checksum. And sending the print permission to the printer device by the compare match with the checksum value calculated with the checksum value this that received.

According to this configuration, various notices or requests can be sent not only to the printer device but also to the host computer that has sent the print data, by the printer board for sending the preset request code.

The printer board transmits / receives the internal state of the printer board to / from a print data transmission source by predetermined data. If the two checksum values do not match, the print data transmission source and the print data transmission source The printer device is automatically requested to perform a retry process.

By this means, print data can be retransmitted from the print data source or the printer board.

[0020]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a functional block diagram showing an embodiment of the present invention. In the print data check method shown in FIG. 1, a printer board 3 connected to a host computer 1 via a LAN (local area network) I / F (interface) 2 is connected to a printer device 4 and an IEEE.
It is assumed that they are connected by a bidirectional parallel peripheral device interface (hereinafter, Centro I / F) based on the standard of 1284.

The difference from the prior art is that the printer board 3 is provided on the print data sending side of the printer device 4 and the printer device 4 not only calculates the checksum but also calculates the checksum on the printer board 3. Are compared, and when they match, print data is printed out from the printer device 4. Also, the printer board 3
Means that the self status can be notified by the host computer 1 and LAN I / F of the data transmission source, or by the printer device 4 and the centro I / F of the print output.

The printer board 3 includes an input / output control unit 31,
It is assumed that a local memory 32, a CPU (central processing unit) 33, a centro data input / output unit 34, a data buffer 35, a calculation unit 36, and a comparison unit 37 are provided. Also,
The printer device 4 includes an input / output control unit 41, a print control unit 4,
2. It is provided with a frame buffer 43, a data buffer 44, a calculation unit 45, and a checksum storage register 46.

The input / output control unit 31 stores data received from the host computer 1 via the LAN I / F 2, including print data, in the local memory 32, while controlling the state in the printer board 3 under the control of the CPU 33. It shall be sent to the computer 1.

The local memory 32 stores data received from the host computer 1 together with the processing program of the CPU 33. The CPU 33 controls the entire printer board 3 by making full use of the processing program of the local memory 32. Further, the centro data input / output unit 34 controls input / output of data as a centro I / F exchanged with the printer device 4.

The data buffer 35 stores print data to be output to the Centro I / F. Arithmetic unit 36
Calculates the checksum from the data input to the data buffer 35. The comparing unit 37 compares the checksum values calculated by the printer board 3 and the printer device 4, respectively.

The input / output control unit 41 of the printer device 4 controls the input / output of data transmitted to and received from the printer board 3. The print control unit 42 controls the print output of the print data. Also, the frame buffer 4
Reference numeral 3 denotes a print control unit 42 which develops print data after being converted into a pattern corresponding to a character code for print output.

It is assumed that the data buffer 44 stores print data for checksum calculation. The arithmetic unit 45 calculates a checksum from the data stored in the data buffer 44. The checksum storage register 46 stores the checksum value calculated by the calculation unit 45.

Next, the transmission and reception data for printing will be described with reference to FIG. 1 and FIG.

The character control codes shown include a carriage return ([cr]) and a form feed ([f
f]) is included. FIG. 2 shows an example in which noise is mixed in the data sent from the printer board 3 and the data is increased by one bit. The first character control code A (hex data 41H) is replaced with the character control code C (hex data 43H) and input to the printer device 4, the hex data of the checksum value has changed from "D3" to "D5".

Next, the main operation procedure of the printer board 3 will be described with reference to FIG. 1 and FIG.

The printer board 3 operates when the CPU 33 performs processing according to a control program downloaded from the host computer 1 to the local memory 32.

First, the printer board 3 inputs data sent from the host computer 1 by the input / output control unit 31 and stores it in the local memory 32 (step S1).

Next, the CPU 33 reads the local memory 3
2 is read out and output to the printer device 4 via the centro data input / output unit 34 (procedure S
2) and read into the data buffer 35 (procedure S
3). Next, the CPU 33 checks whether the data read into the data buffer 35 is a page break code (step S4).

If this step S4 is "NO" and the read data is not a form feed code, the arithmetic unit 36 adds a checksum to the read data,
The checksum value of the operation result is stored in the comparing unit 37 (step S5). By this storage, the procedure returns to the above-described step S2 in which the CPU 33 reads out one piece of data stored in the local memory 32 and outputs the data to the printer device 4 via the centro data input / output unit 34.
Are repeated until the procedure S4 is "YES" and a page break code is input.

If the above step S4 is "YES" and the read data is a page break code, the CPU 33 calls the printer device 4 by the bidirectional centro function and reads the stored checksum value from the printer device 4 ( Procedure S
6) Send to comparison section 37. The comparing unit 37 compares the checksum value stored in step S5 with the checksum value read in step S6 (step S7), and checks for a match (step S8).

If the step S8 is "YES" and the checksum values match, the CPU 33 generates a print permission code in response to the check sum value, and outputs the code to the printer 4 via the Centro I / F.
The print permission code is output to the printer (step S9), and the procedure ends.

On the other hand, if the above step S8 is "NO" and the checksum values do not match, the CPU 33 performs a retry process on the print data for which transmission has failed (step S10).

In the retry process in this case, the initialization instruction code is output from the printer board 3 to the printer device 4 because the data transfer between the printer board 3 and the printer device 4 has failed.

Next, a main operation procedure of the printer device 4 will be described with reference to FIG. 1 and FIG.

The printer device 4 stores a control program in the print control section 42, and operates by performing processing according to the control program.

First, in the printer device 4, the input / output control unit 41 inputs data sent from the host computer 1 one by one through the printer board 3, and reads the data into the print control unit 42 and the data buffer 44 ( Procedure S2
1), together with a page break code (step S22), a print permission code (step S23), an initialization instruction code (step S24), and a checksum call code (step S23). Check.

If these steps S22 to S25 are "NO" and not these codes but print data,
On the one hand, the print data in the print control unit 42 is developed into a pattern on the frame buffer 43 (procedure S26). On the other hand, the arithmetic unit 45 adds the checksum to the print data in the data buffer 44 (procedure S27). ). The addition result of the operation unit 45 is stored in the checksum storage register 46 (step S28), and then returns to the first step S21 to wait for the next data input.

If the above step S22 is "YES" and the input data is a page feed code, the printer 4 executes the first step S22.
Return to step 21 and wait for the next data input.

If the determination in step S23 is "YES" and the input data is a print permission code, the print control unit 42 performs data print output processing (step S31).

If the above-mentioned step S24 is "YES" and the input data is the initialization instruction code, a retry process has occurred on the printer board 3, so the input / output control unit 41 controls the print control unit 42 and the printer device 4. The function is initialized (step S32).

If the above step S25 is "YES" and the input data is a checksum read code, the input / output control unit 41 reads the checksum value stored from the checksum storage register 46 and
(Step S33), and then returns to the first step S21 to wait for the next data input.

In the above description, only the operation for data input is performed. However, as described above, the input / output control unit 31 can notify the state of the printer board 3 to the host computer 1 of the connection destination. At the time of the retry processing, it is possible to request the host computer 1 to retransmit print data in a predetermined format as needed.

In the above description, the functional blocks and the operation procedure have been illustrated and described. However, a change in the block configuration due to the separation / merging of the functions or a change in the order of the procedures can be freely made as long as the above functions are satisfied. It does not limit the invention.

[0050]

As described above, according to the present invention, a printer board is provided on the print data input side of a printer, and input / output control of data transmitted and received between the printer and the printer board is performed. Enables input / output control of data transmitted to and received from the print data source.Printer board checks print data and stops print output processing of printer if any error occurs in print data. As a result, a print data check method capable of notifying the print data sending source of an abnormality is obtained.

With this configuration, the occurrence of an abnormality in data transferred from the printer board to the printer can be detected.
The print output can be stopped, a retry process of sending print data again from the printer board can be performed, and further, a retry process of requesting a print data sending source from the printer board and sending print data can be obtained. .

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of transfer data in which an abnormality has occurred in the present invention.

FIG. 3 is a flowchart showing an example of a main operation procedure of the printer board in FIG. 1;

FIG. 4 is a flowchart illustrating an example of a main operation procedure of the printer device in FIG. 1;

FIG. 5 is a functional block diagram showing an example of the related art.

FIG. 6 is an explanatory diagram showing an example of transfer data in which an abnormality has occurred in FIG. 5;

FIG. 7 is a flowchart illustrating an example of a main operation procedure of the printer device in FIG. 5;

[Explanation of symbols]

 Reference Signs List 3 printer board 4 printer device 31, 41 input / output control unit 32 local memory 33 CPU (central processing unit) 34 centro data input / output unit 35 data buffer 36, 45 calculation unit 37 comparison unit 42 print control unit 43 frame buffer 44 data buffer 46 Checksum storage register

Claims (4)

[Claims] In a print data check method for checking when print data is received by a printer device, the printer device includes a printer device having a two-way communication function and a printer board. Received via the printer board, calculates and stores the checksum of the received print data, returns the stored checksum value to the printer board in response to the checksum request, and permits printing from the printer board. While receiving the print data, the printer board prints out the received print data, while the printer board sends the received print data to the printer device and calculates a checksum of the print data. And receives the checksum, and the received checksum value and the calculated checksum value are A print permission is sent to the printer device in accordance with the comparison of the print data. 2. The print data check method according to claim 1, wherein the two-way communication function is a function based on a two-way parallel peripheral device interface (two-way centro I / F) defined by IEEE1284. 3. A print data check method according to claim 1, wherein said printer board transmits and receives internal states of said printer board by predetermined data to and from a print data transmission source. 4. The print data check according to claim 1, wherein the printer board requests a retry process from a print data sending source and the printer device when the two checksum values are not compared. method.