JPH0254328A - Time-over preventing system for printer - Google Patents

Abstract

PURPOSE:To actuate a page printer which can produce the beautiful forms of printed characters by starting a timer and forcibly sending the ready signals to a host device every fixed time when a reception buffer of the page printer is filled with data. CONSTITUTION:When a buffer full state detecting circuit 12 detects the full state of a buffer, a busy signal is turned on to control a switch 2. Thus the data received hereafter from a host device are applied to an auxiliary buffer 4 and a timer 13 is started. In this respect, the timer 13 has a monitor time shorter than the busy time that is monitored at the host side. Then the busy signal sent to the host device from an interface control circuit 1 is forcibly turned off, i.e., set ready when a time-up signal is outputted from the timer 13. When the ready signal is ready, the next data is applied to the buffer 4 from the host device. At the same time, the timer 13 is started again by a stroboscopic signal.

Description

[Detailed Description of the Invention] [Summary] A reception buffer is provided, and a data transmission signal (
Regarding the time-over prevention method in a page printer that operates under the monitoring control of a busy signal after receiving a flash (strobe), a page printer is connected in copy mode to a host device that controls a serial printer, and a busy signal is detected. The purpose of this method is to prevent the host from detecting a timeout even if the period becomes long, and is a means of detecting when the data stored in the receive buffer provided in the page printer is full. When it is detected that the receiving buffer is full, a timer is started and a ready signal is sent back to the host device at fixed time intervals (T,).

[Industrial application field]

The present invention relates to a time-over prevention method in a page printer that is equipped with a reception buffer and operates under the monitoring control of a busy signal after receiving a data sending signal (strobe) from a host device.

With the recent spread of office automation (OA), quiet non-impact printers such as thermal transfer printers and laser printers have come to be used in offices.

On the other hand, high-speed (20 pages/minute to 30 pages/minute) page printers have traditionally been used in medium-sized or larger computer systems, but because they are expensive, they have been used in computer systems, which are representative of the OA equipment mentioned above. was not used.

Therefore, in the personal computer, etc., a normal serial printer or the like is used, and the current situation is that the timeout monitoring for the printer is also set at a timeout time that matches the serial printer.

However, recently, 6 pages ~
Although it has a low speed of 8 pages per minute, a small and low-cost page printer has been developed based on a laser printer and has come to be used as office automation equipment.

This is because it has advantages such as clear printed characters, high resolution, and the ability to use plain paper1, making it suitable as the office automation equipment.

However, in the case of the page printer, when you set the copy mode, you can set the number of copies, so for example, you can set the number of copies to 1.
00 sheets, even with the above 8 pages/minute printer, 1
00 ÷ 8 = 12.5 minutes of busy time is required, and there is a problem of time over when monitoring with a conventional PC of about 30 seconds to 3 minutes, so connect the small page printer in copy mode. A time monitoring method is required that does not cause a timeout.

[Prior art and problems to be solved by the invention] FIG. 2 is a diagram explaining a time-over monitoring method in a conventional printer, in which (a) shows a schematic configuration of the printer side;
b) shows an operation time chart.

First, in Figure (a), when data is normally sent from a host such as a personal computer (not shown) to a printer, an abnormality in the printer causes the host to wait for data transfer and stop data processing. To prevent this, monitor the printer's busy time.

When this busy time exceeds a certain value, the host assumes that the printer is abnormal and operates to perform abnormality processing for a specific input/output device.

This busy monitoring is generally performed as follows.

In other words, one piece of data (for example, one piece of 8-bit data) is sent from the host.
) is sent to the printer along with a strobe signal ■ indicating the validity of the data ■.

When the printer receives the data (■) and the strobe signal (■) in the interface control circuit 1, it immediately sends a busy signal (■).
is returned to the host and the processing of the data (for example, transfer processing to the reception buffer 3) is completed, the busy signal
Set to °off” (ready).

Normally, if the receive buffer 3 is empty, the next data can be received by simply transferring the one data item to the receive buffer 3, so as shown in figure (b), , the busy signal (2) can be turned off in a short time T.

In parallel with the data transfer operation from the host, the data transferred to the reception buffer 3 is extracted one character at a time and decoded by the decoder 5. If it is character information, it is converted into dot data, for example, and sent to the print processing section. The data is stored in a line buffer (not shown) in 6.

Since the transfer process from the host is faster than this decoding and storage process in the line buffer, even if the receiving buffer 3 has a capacity of only a few lines, it will eventually become full (buffer full).

When this buffer full is detected, the decoder 5
For example, the characters decoded by
In the case of a serial printer, if the code is a code), it is recognized as a print instruction and performs printing and line feed processing, so when the printing and line feed processing are completed, one line of data is received. The next data cannot be transferred to the receive buffer 3 until it is cleared from the buffer 3. Therefore, T in figure (b)
As shown by , the busy time is longer than normal data reception (Tb described above).

If the printer is a page printer, per page,
For example, the busy state is not canceled until printing of 64 lines is completed. Even in this case, the busy time is about several seconds at most.

On the other hand, when the host sends out one data item, it starts a timer within its own device, and when it recognizes that the busy signal from the printer is off, that is, ready, it resets the timer. However, if the busy signal ■ turns off late (in figure (b),
(TO<TF), the timer outputs a timeout signal, and the host functions to assume that the printer is abnormal.

Typically, the time setting value for this timer is
Assuming a line printer etc., what is the capacity of the receive buffer 3 on the printer side? (Usually, it has a capacity of several lines or one page.) Depending on the print format (line by line, page by page, etc.), it takes, for example, about 30 seconds to 3 minutes.

However, recently, the previously used page printers (for example, laser printers) are increasingly being connected to personal computers, etc., instead of serial printers or line printers.

In this case, since the page printer has a copy function (copy mode) and the number of copies can be set, for example, if the number of copies is set to 100, even if the printer prints 8 pages per minute, As shown in the figure, a busy time of 12.5 minutes is required, and there is a problem in that a busy time of about 30 seconds to 3 minutes, which is monitored by a conventional personal computer, ends up being timed out.

If the timer setting time on the personal computer side was increased to, for example, about 30 minutes in accordance with the above-mentioned copy function, there was a problem that the timer would no longer be effective as an original timer monitoring mechanism.

In view of the above-mentioned conventional drawbacks, the present invention includes a receiving buffer,
In a page printer that operates under the monitoring control of a busy signal after receiving a data sending signal (strobe) from a host device, the page printer is set in copy mode to the host device that controls the serial printer, etc. It is an object of the present invention to provide a time-over prevention method that does not detect a time-out at the host even when a connection is made and the busy period becomes long.

[Means to solve the problem]

The above problem can be solved by a time-over prevention method in a printer configured as follows.

(1) In a printer equipped with a reception buffer and operated under the monitoring control of a busy signal after receiving a data transmission signal from a host device, detecting that the data stored in the reception buffer is full. When the means detects that the receiving buffer is full, it starts a timer and runs it for a certain period of time (T6).
The configuration is such that a ready signal is sent back to the host device each time.

(2) When the above reception buffer becomes full and the timer is activated, the data from the host device is stored in an auxiliary buffer different from the reception buffer, and when the reception buffer becomes empty. , the data stored in the auxiliary buffer is fed back to the reception buffer.

[Effect]

That is, according to the present invention, in a page printer that includes a reception buffer and operates under the monitoring control of a busy signal after receiving a data sending signal (strobe) from a host device, an auxiliary buffer and the above-mentioned reception buffer are provided. If a timer is added to monitor the busy time when the buffer becomes full (buffer full), and the monitoring time is T, then the Tm
< To.

When it is detected that the receive buffer is full (buffer full), the timer is started, and after the above monitoring time T, when the receive buffer becomes free and ready before time-up, the timer is started. However, if there is no free space in the reception buffer even after the time T1, the busy function is forced to be turned off after the time T11 after the time-up.

As mentioned above, since TI < TH, printer errors are not detected by busy check on the host side.

When the host detects the ready state, data is sent again, so it returns busy and, in the case of the present invention, inputs this data into the auxiliary buffer.

When this data transmission from the host is detected, the timer of the present invention is started again, and if there is no empty space in the reception buffer even after the time T11,
It is forcibly made ready, and the data is sent (and then inputted into the auxiliary buffer), which is repeated.

Inside the page printer, in parallel with the above operations,
As the data is being decoded and printed, if the receive buffer becomes empty, the data stored in the auxiliary buffer is filled into the receive buffer, and the auxiliary buffer becomes empty. Then it returns to normal reception status.

Because it operates in this way, even when a page printer is connected to a "personal computer" level host and printing is being performed in copy mode, it can be used without the need for a practical timer mechanism for ordinary serial printers, line printers, etc. This has the effect of allowing a page printer using a laser printer to be operated with clear printed characters without detecting a timeout.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention, in which (a) shows a schematic configuration of a page printer, (b) shows an operation time chart when the present invention is implemented, and (a) )
Timer 13. Auxiliary buffer 4, switch 2. A means necessary for the present invention is to forcibly turn off (ie, ready) the busy signal (2) in the interface control circuit 1 using the time-up signal (2) of the timer 13.

Note that the same reference numerals indicate the same objects throughout the figures.

Hereinafter, the time-over prevention method of the present invention will be explained with reference to FIG.

Even if the present invention is implemented, the basic operation between the host and the printer will not change, so it will be omitted here. The following description will focus on the operation after detection in step 12.

In the page printer shown in the figure, when the receiving buffer full detection circuit 12 detects that the receiving buffer is full, that is, "buffer full", it immediately turns on the busy signal (2) as in the conventional case, and at the same time, The switch 2 is controlled to transfer subsequent data from the host to the auxiliary buffer 4 of the present invention.
and the timer 13 of the present invention
Start.

In parallel with this operation, the decoder 5 decodes a single character, and the character is, for example, a page break code (FF
), the page printing operation begins.

If the print mode at this time is the above-mentioned copy mode provided in this page printer, for example, as mentioned above, it is necessary to print 100 copies, so printing of the 100 copies is completed. Until then, there will be no "vacancy" in the reception buffer 3.

Therefore, in the present invention, a timer 13 is provided which has a monitoring time T shorter than the busy time T0 monitored on the host side, and when the time amplifier signal ■ is output, it is sent from the interface control circuit 1 to the host. The busy signal (2) is forced to be turned off, that is, to be "ready."

When the busy signal ■ becomes "ready", the next data ■ is sent from the host along with the strobe signal ■, but as mentioned above, the switch 2 is gated to the auxiliary buffer 4, so the data is At the same time, the time 13 of the present invention is inputted to the auxiliary buffer 4, and the strobe signal
will be restarted. (Refer to the operation time chart in figure (b)) The above operation is performed after the above copy operation is completed.
This process is repeated until there is "empty space" in the reception buffer 3.

When the printing of the number of copies is completed and one page's worth of data is deleted from the reception buffer 3, there will be "empty space" in the reception buffer 3, so until then, the auxiliary buffer 4 is The accumulated data is packed into the reception buffer 3 via the switch 2, and when the auxiliary buffer 4 becomes empty, the normal reception state is returned.

The capacity of the auxiliary buffer 4 is determined by the host busy timer time TH and the maximum processing time of the page printer (for example,
(during copy mode).

As described above, the present invention provides a page printer that is equipped with a reception buffer and operates under the monitoring control of a busy signal after receiving a data transmission signal (strobe) from a host device, when operating in copy mode. To prevent time-overs, when it is detected that the receive buffer is full, a timer is started to monitor the busy state when the receive buffer is full, and the host's busy monitoring time (T1
1) The feature is that a ready signal is forcibly returned to the host by the time-up signal (2) that is output after a shorter fixed period of time (d), so that the host does not have to worry about busy monitoring.

〔Effect of the invention〕

As explained above in detail, the time-over prevention method in the printer of the present invention includes a reception buffer and operates under the monitoring control of a busy signal after receiving a data transmission signal (strobe) from a host device. In a page printer, it is a means for detecting when the data accumulated in the receiving buffer provided in the page printer is full, and starts a timer when it is detected that the receiving buffer is full. The system is designed to forcibly send a ready signal back to the host device at fixed intervals (T++), so a page printer is connected to a "personal computer" level host and printing is performed in copy mode. This has the effect of allowing a page printer using a laser printer with clear printed characters to be operated without detecting a timeout due to a practical timer mechanism for ordinary serial printers, line printers, etc.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention. FIG. 2 is a diagram illustrating a time oats 1' monitoring method in a conventional printer. It is. In the drawings, 1 is an interface control circuit 2 is a switch, and 3 is a receiver sofa. 4 is an auxiliary buffer; 5 is a decoder; 6 is a print processing unit. 12 is a reception buffer detection circuit. 13 is a timer. ■ is data, ■ is strobe signal. ■ is a busy signal or ready signal. ■ is the time-up signal of timer 13. T, is the busy monitoring time at the host. T is the busy monitoring time by timer 13. T, is the busy time when the receive buffer is not full.

Claims (2)

[Claims] (1) Equipped with a reception buffer (3), which receives a busy signal ([3]) after receiving the data transmission signal ([2]) from the host device.
]), the means (12) for detecting that the data stored in the receive buffer (3) is full;
) is full, the timer (13)
A time-over prevention method for a printer, characterized in that a ready signal ([3]) is sent back to a host device at fixed time intervals (T_B). (2) When the reception buffer (3) becomes full and the timer (13) is started, data from the host device is stored in an auxiliary buffer (4) different from the reception buffer (3); When the reception buffer (3) becomes 'empty', the data stored in the auxiliary buffer (4) is
2. The time-over prevention method in a printer according to claim 1, characterized in that feedback is sent back to the receiving buffer (3).