JP3225883B2 - Network adapter for printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printer net.
Work adapter.

[0002]

2. Description of the Related Art Conventionally, a printer network adapter shown in FIG. 4 has been known as this kind of technology. In FIG. 1, a printer network adapter 1 is mounted in a slot (not shown) of the printer pr, and is connected to a predetermined network via a network interface unit 2. Then, a connection request (print request) from the terminal on this network to the printer pr
Is transmitted, the connection request is sequentially input to the packet transmission / reception unit 3 and the packet determination unit 4.

The packet determining unit 4 registers a transmission source of a connection request in a predetermined management table to establish a connection, and causes the packet transmitting / receiving unit 3 to transmit a predetermined packet to a destination of the connection to transmit print data. Prompt (connection activation). Thereafter, reception of the print data is started from the establishment destination of the connection, and the print data is stored in a buffer memory (not shown) of the printer pr via the print data control unit 5 and the printer interface unit 6.
When the reception of all the print data is completed, the active connection is released, the next connection is activated, and the reception of the print data is started.

[0004] During reception of print data, the packet judging unit 4 monitors packets other than the print data, and when detecting a connection release request (print stop request) from the source of the print data, forcibly switches the active connection. And activates the next connection to start receiving print data.

A timer 7 for measuring a predetermined time is connected to the packet judging unit 4. A reset signal is sent to the timer 7 every time print data is received, and the print data is completely received. Then, the timer unit 7 terminates the time counting process. However, if the timer unit 7 measures a predetermined time before receiving the reset signal from the packet determination unit 4, the timer unit 7 notifies the forced connection release unit 8 of that fact.

Then, the connection forcible release unit 8 forcibly releases the active connection, selects the next connection to be activated, notifies the packet transmitting / receiving unit 3 and sends the packet to the establishment destination of the connection. Then, transmission of print data is urged, and reception of print data is started in the same manner.

[0007]

The conventional printer network adapter described above has the following problems. An active connection is released when a connection release request from a print data transmission source or a stop of communication due to a network failure or the like is detected.
However, since print data received through the released connection remains in the buffer memory of the printer pr, this print data may be printed abnormally.

The present invention has been made in view of the above problems, and provides a network adapter for a printer capable of preventing abnormal printing even when abnormal printing data is received.
With the goal.

[0009]

In order to achieve the above object, the present invention provides a method for storing received print data in a predetermined storage medium.
Memorize and respond to the specified print data discard command.
A printer that can be attached to or detached from a printer that discards stored print data.
A network adapter for a printer, the network adapter
Print data to receive print data in response to a print request via
Monitor the receiving status of the print data
Abnormal reception detecting means for detecting reception, and abnormal reception detection
When the means detects abnormal reception, the printer
Abnormal reception data discard control procedure that outputs print data discard command
And a step.

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

That is, a network detachable from a printer
Network adapter to receive print data and
The print data reception status is monitored to detect abnormalities and
When normal reception is detected, the print data is sent to the printer.
Output the discard instruction of the data.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a printer network adapter 10 and a printer PR according to an embodiment of the present invention.
Is shown in a block diagram. In FIG. 1, a printer network adapter 10 is mounted in a slot (not shown) of the printer PR, and is connected to a predetermined network via a network interface unit 20. Of course, an unspecified number of packets exist on the same network, and the packets detected by the network interface unit 20 are input to the packet determination unit 40 via the packet transmission / reception unit 30.
The packet determination unit 40 determines whether the packet is addressed to itself, and receives only the packet addressed to itself.

Further, the packet judging unit 40 analyzes the received packet and detects whether the received packet is a connection request (print request) packet, a print data packet, or a connection release (print interruption) packet. When the connection request packet is detected, the network address of the transmission source of the packet is registered in a management table (not shown) to establish a connection, and the print data control unit 50 is notified to determine whether the printer PR can receive the print data. Detect whether or not.

Here, when the reception is detected, the fact is notified to the transmission source of the connection request via the packet transmission / reception unit 30 to urge the transmission of the print data (connection activation), and the received print data is activated. Is output to the print data control unit 50. This print data control unit 50
The input print data is transferred to the printer interface unit 60.
Through a printer memory (not shown) of the printer PR. Therefore, the network interface unit 20
The printer interface unit 60 constitutes print data receiving means.

The packet judgment unit 40 includes a timer control unit 70
Is connected to the timer control unit 70, and a timer unit 71 that measures time for a predetermined time is connected to the timer control unit 70. Then, when the reception of the print data is started, the packet judging unit 40 notifies the timer control unit 70 to perform the timer check according to the flowchart shown in FIG. In the figure, in step S105, when the timer control unit 70 receives the notification from the packet determination unit 40, the timer unit 71 is reset. Of course, if the timer unit 71 is not operating, it is operated at this time. Then, in step S110, it is detected whether or not there is a notification from the packet determination unit 40, and if there is a notification from the packet determination unit 40, step S105
And reset the timer unit 71 again. Further, in step S115, the timer unit 71 measures a predetermined time to detect whether or not a timeout has occurred. If the timeout has occurred, the timer unit 71 notifies the forced connection release unit 80 in step S120. To release the active connection.

The packet judging unit 40 monitors whether the received print data is the last print data in one connection, and forcibly terminates the timer check when the last print data is received. With
Release an active connection. Thereafter, a predetermined print command is output to the print data control unit 50, and the print data control unit 50 causes the printer PR to execute a print process. That is, the timer check detects an abnormal reception such that the reception of the print data is interrupted before the print data is completely received due to a network failure or the like.

By the way, the packet judging unit 40 monitors other packets even while receiving print data.
When a connection request packet is received mixed with print data, a connection is established as described above. However, when print data is being received by one active connection, print data of another connection cannot be received, and such a connection is in a print data transmission waiting state. Packet determination unit 40
When the print data being received is completely received as described above, the management table is searched to detect the presence or absence of a connection in a print data transmission wait state. Activate the connection and start receiving print data.

On the other hand, when the packet judgment section 40 receives the connection release packet, it searches the management table and releases the corresponding connection. At this time, if the connection is active, the print data discard control unit 9
Notify 0. Thereafter, if there is a connection waiting for print data transmission, the connection is activated to start receiving the next print data. That is, the packet determination unit 40 not only detects abnormal reception due to a network failure or the like by using the timer control unit 70 and the timer unit 71, but also detects print data canceled halfway and received halfway as abnormal reception. I have. Therefore, the packet determination unit 40, the timer control unit 70, and the timer unit 71 constitute an abnormal reception detection unit.

Upon receiving the timeout notification from the timer control unit 70 as described above, the connection forcible release unit 80 searches the management table to forcibly release the active connection, and then releases the print data discard control unit 90. Notify. Thereafter, if there is a connection waiting for print data transmission, a packet for prompting the transmission of the print data is transmitted to the establishment destination of the connection via the packet transmission / reception unit 30 (connection activation) to start receiving the print data. I do.

When the print data discarding control unit 90 receives the notification from the packet judgment unit 40 or the forced connection release unit 80, it outputs a print data discarding command to discard the print data being received to the print data control unit 50. Then, the print data control unit 50 issues the print data discard instruction via the printer interface unit 60 to the printer PR.
Output to Then, the printer PR discards the corresponding print data according to this command.

Therefore, the connection forced release unit 80 is marked.
The printing data discarding control unit 90 and the abnormal reception data discarding unit
Constitute. As a result, the print data received abnormally is
It was surely discarded from the buffer memory of the printer PR
Therefore, abnormal printing does not occur.

Next, the operation of the present embodiment will be described with reference to the flowchart of the packet judging section 40 shown in FIG. In the figure, the packet determination unit 40 has received a packet addressed to itself via the network interface unit 20 and the packet transmission / reception unit 30, and if a connection request packet has been received in step S205, the process proceeds to step S2.
In step 10, the network address of the transmission source of the packet is registered in a management table (not shown) to establish a connection. In step S215, whether the printer PR can receive print data via the print data control unit 50 and the printer interface unit 60 is determined. Is detected. This step S2
If the reception is detected in step S15, the next step S22
At 0, this is notified to the establishment destination of the connection via the packet transmission / reception unit 30 to urge the transmission of the print data.

When the transmission of the print data is started and the packet judging unit 40 detects the print data packet in step S225, the received print data is returned in step S230 while responding to the transmission source of the print data packet. The print data is output to the control unit 50, and the print data
Is forwarded to Thereafter, in step S235, it is determined whether or not the received print data is the last print data. When the received print data is not the last print data, the timer control unit 70 is notified in step S240 to start the timer check.

In this timer check, the packet judging unit 40 monitors the reception of the print data packet, and uses the timer control unit 70 and the timer unit 71 to receive the print data for a predetermined time or more before completely receiving the print data. It is detected whether or not is interrupted. Then, when the reception of the print data is interrupted and a timeout is detected, the connection forced release unit 8
Notify 0. Then, the connection forced release unit 80
Releases the active connection and notifies the print data discard control unit 90 to forcibly discard the print data stored in the printer PR. Further, the connection forcible release unit 80 notifies the packet transmission / reception unit 30 to activate the next connection, and starts receiving print data from the connection.

On the other hand, when the packet judgment section 40 detects the last print data packet in step S235, the timer check is forcibly terminated in step S245.
After the connection is released in step S250, a print command is output to the print data control unit 50 in step S255. Then, the print data control unit 50 transfers the print command to the printer PR via the printer interface unit 60, and outputs the print data received by the printer PR. Thereafter, in step S260, it is detected whether or not there is a connection waiting for print data transmission. If there is, in step S265, the connection is activated to start receiving the next print data.

When the connection release packet is received in step S270, the connection is released in step S275, and in step S280, the print data discard control unit 90 is notified to discard the data being received. Thereafter, if there is a connection waiting to transmit print data in step S285, the connection is activated in step S290 to start receiving the next print data.

As described above, when print data is received in response to a print request via the network via the network interface unit 20 to the printer interface unit 60 and is stored in the buffer memory (not shown) of the printer PR, the packet determination unit 40 The timer control unit 70 and the timer unit 71 monitor the reception status of the print data, and when the abnormal reception is detected, the connection forcible release unit 80 and the print data discard control unit 90 store the received data in the buffer memory. Print data is discarded. Therefore, it is possible to provide a network printer and a printer network adapter that can prevent abnormal printing even when print data is abnormally received.

[0033]

As described above , according to the present invention , the program
Abnormal reception by adapter that can be attached to or detached from the linter
Since the print data is discarded, the printer and
According to the operating environment, as long as
To replace only the printer network adapter.
Both are possible and highly versatile.

[0034]

[Brief description of the drawings]

FIG. 1 is a block diagram showing a connection status between a printer network adapter and a printer according to an embodiment of the present invention.

FIG. 2 is a flowchart of a timer check.

FIG. 3 is a flowchart of a packet determining unit.

FIG. 4 is a block diagram showing a connection state between a printer network adapter and a printer according to a conventional example.

[Explanation of symbols]

 Reference Signs List 10 network adapter for printer 20 network interface unit 30 packet transmission / reception unit 40 packet determination unit 50 print data control unit 60 printer interface unit 70 timer control unit 71 timer unit 80 connection forced release unit 90 print data discard control unit

Claims (1)

(57) [Claims] 1. A printer network adapter which stores received print data in a predetermined storage medium and which is detachable from a printer which discards the stored print data in response to a predetermined print data destruction command. Print data receiving means for receiving print data in response to the print request, abnormal reception detection means for monitoring the reception status of the print data and detecting abnormal reception, and when the abnormal reception detection means detects abnormal reception. A network adapter for a printer, further comprising abnormal reception data discarding control means for outputting the print data discard command to the printer.