JPH0484315A - Printer controller - Google Patents

Abstract

PURPOSE:To unify the utilization of signal lines and to eliminate the need for considering the connection of signal lines as a host equipment even when the kinds of printer devices are different from each other by outputting the data input inhibiting cause, etc., of the printer device by using standard signal lines of a busy signal line, etc.. CONSTITUTION:When a test command, etc., for inquiring the details of the printing status of a printer is transmitted to the printer from host equipment while the 1st signal outputting means 1 transmits that the reception of printing data is impossible, the test command, etc., is discriminated by means of an output signal control means 3. Based on the discrimination, the transmission line of the signal outputted to the standard signal line of a 'Centronics(R)' interface is switched to the transmission line of the signal outputted from a 2nd signal outputting means 2. Then the means 2 transmits signals indicating the detailed status of the printer as serial signal of plural bits. Therefore, plural different kinds of printers can be controlled based on the same control circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer control device that outputs various printer status signals to a host computer via a standard signal line of a Centronics interface.

〔overview〕

In the Centronics interface, status signal lines are used to transmit and receive signals other than basic control signals, without using standard signal lines.

However, since the method of using the status signal line differs depending on the model, printers of different models cannot be controlled in the same manner.

The present invention converts printer status signals other than basic control signals, such as paper out signals and paper jam signals, into serial data, and provides signal switching means to the standard signal line of the Centronics interface, thereby achieving common specifications. This allows printer status signals converted into serial data to be transmitted via standard signal lines for basic control signals. This allows different models to be controlled in the same way.

[Prior Art] Printer devices such as LED printers, LCS printers, and laser printers usually exchange data with a host computer via a Centronics specification interface. Then, the host computer outputs character codes and print control commands as print data to the printer device, and the printer device outputs a busy signal instructing the output of data such as character codes to the host computer.

Conventionally, output control of character codes and the like of a host computer has been determined and controlled by detecting the output level of a busy signal ("H" or "L" signal potential). For example, if the busy signal is on (“H”), the printer is unable to receive print data; if it is off (“L”), it is possible to receive print data, and the host computer will print based on the busy signal. Controls data transmission. In addition, conventionally, when trying to find out in more detail the cause of the inability to receive print data, it is possible to use unused signal lines of the Centronics interface as status lines for transmitting and receiving various status signals of the printer device. It is configured such that when the printer is connected and a predetermined command is sent from the host computer to the printer, the printer sends an output signal in response to the command. For example, when a printer malfunctions such as out of paper or paper jam, the out of paper signal,
A printer status signal indicating a state in which the printer cannot receive a paper jam signal or the like can be transmitted via the previously connected unused signal line. Then, on the host computer side, by receiving the printer status signal, it determines the more detailed status of the printer in which reception is not possible, and performs processing corresponding to the status.

[Problems to be Solved by the Invention] As mentioned above, the output of the status signal of the conventional printer device is
This is done via the unused signal lines of the Centronics interface.

As mentioned above, when using an unused signal line as a status line, the method of using the signal line is inconsistent depending on the printer model or host computer model, so the signal line used may differ depending on the printer model. Different printer devices cannot be controlled by the same printer control circuit.

Further, in the conventional configuration as described above, one status line is required for each cause of unreceivable reception, and therefore, the number of status lines necessary to notify the host computer of the cause of unreceivable reception is required.

In this case, it would be better to use a standard signal line (for example, a busy signal line) that is uniformly controlled between the printer device and the host computer, and to be able to output various causes of unreceivable reception.

An object of the present invention is to enable the cause of reception failure to be output using a standard signal line without using a special status line.

[Means to solve the problem] The means of the present invention are as follows.

First signal output means 1 (see block diagram in Fig. 1,
(the same applies hereafter) notifies the presence or absence of a state in which data cannot be received from the host device to the printer device.

For example, among the signals indicating the print status, a standard signal such as a busy signal indicating that printing data such as a character code from a host device such as a host computer cannot be input is output.

The second signal output means 2 notifies the cause of the unreceivable state. For example, when the first signal output means indicates that printing data cannot be input, among the signals indicating the print status, a non-standard signal indicating a detailed print status such as no paper is converted into serial data and output. do.

For example, when the host device requests notification of the detailed status of the printer, the output signal control means 3 outputs the signal from the second signal output means instead of the signal output from the first signal output means. Output signal switching control is performed so that the signal outputted by the first signal output means is outputted to the same signal line to which the signal was outputted.

[For production] The operation of the means of the invention is as follows.

Now, if the output level of the busy signal is turned on by the first signal output means 1, and a message indicating that print data cannot be received is transmitted, the host device sends a test command or the like to inquire about the details of the print status to the printer. .

Then, the test command is discriminated by the output signal control means 3, and based on the discrimination, the switch element etc.
The signal transmission path outputted to the standard signal line of the Centronics interface by the first signal output means 1 is switched to the signal transmission path outputted by the second signal output means 2. Then, a signal indicating the detailed status of the printer is converted into a multi-bit serial signal (serial data) and transmitted to the switched signal transmission path by the second signal output means 2.

In this way, the status signals of all printers can be transmitted via the standard signal line, which is a common signal transmission path even for different models, so it is possible to control multiple different printer models based on the same control circuit. becomes possible.

Therefore, without using a special status line,
The cause of unreceivable reception, etc. can be output using a standard signal line.

[Example] An example will be described below with reference to FIGS. 2 to 4.

FIG. 2 is an internal configuration diagram of a printer control device according to an embodiment.

The printer control unit 0 outputs a strobe signal S via the Centronics interface 11 to notify the output of a data signal from a host computer (not shown).
and a data signal An consisting of character codes and control commands.
is input to the printing device 12 based on the data signal An.
control.

Further, the printer control unit 10 cannot read print information when the printer control unit 10 is importing data, when the printing device 12 is printing, feeding paper, out of paper, paper jam, or out of ribbon. When a busy signal is generated to notify that the print information is not readable, a parallel signal p is output to the output signal converter 13, and a parallel signal p is generated to notify the status that is the cause of the inability to read the print information.

The printing device 12 includes a paper feeding section, a printing section, a drive motor, etc., and converts dot pattern data (data obtained by converting the above-mentioned character code by a character generator (CG) not shown) output from the printer control section 10 into dot pattern data. Execute printing based on

The output signal converter 13 includes a serial data transmitter 13a,
Changeover switch 13b, busy signal output terminal 13c,
It consists of a serial data output terminal 13d, etc. The output signal converter 13 also outputs the busy signal p input from the printer controller IO to the busy signal output terminal 13c, and converts the parallel signal p input from the printer controller 10 into start-stop synchronization by the serial data transmitter 13a. It converts into serial data of the formula and outputs it to the serial data output terminal 13d.

The signals output to the busy signal output terminal 13C and the serial data output terminal 13d are output from the changeover switch 13.
b is output to the busy signal line of the Centronics interface.

One terminal of the changeover switch 13b is switched and connected to the busy signal output terminal 13C and the serial data output terminal 13d, and the other terminal is connected to the busy signal line of the Centronics interface. The switching of the output signals by the changeover switch 13b is performed by the output signal conversion section 13 based on a control signal from the printer control section 10.

Next, the control operation of the printer device configured as described above will be explained.

3 and 4 are time charts of the Centronics interface. In Figure 3, from tl to t2
This indicates that the printer is currently printing.

Print data AI and A2 are output from the host computer via data signal lines, and a strobe pulse signal S is output via a strobe signal line. If the printer runs out of paper at t2 and the printer stops printing,
The printer control unit 10 detects the paper out condition,
The busy signal is output to the busy signal output terminal 13c,
Switch 13 to switch to the busy signal output terminal 13C
Since b is normally connected, its selector switch 1
As shown in FIG. 3, a busy signal is output to the busy signal line via line 3b. When this busy signal is detected, the host computer issues a test command A requesting the printer to notify the printer in detail of the state in which it is unable to accept print data (busy state), as shown in FIG.

is output via the data signal line. In response to this output test command, the printer control section 10 outputs a parallel signal p consisting of status signals of each part of the printer to the output signal conversion section 13 in order to notify in detail the state in which print data cannot be accepted. . Then, it requests the output signal converter 13 to convert the output parallel signal p into serial data D and output it to the serial data output terminal 13d, and to connect the changeover switch 13b to the serial data output terminal 13d. The output signal converter 13 converts the parallel signal p input to the serial data transmitter 13 into serial data D according to a request from the printer controller IO, connects the changeover switch 13b to the serial data output terminal 13d, and As shown in FIG. 4, the converted serial data D is output to the busy signal line.

In this way, the host computer analyzes the serial data output via the busy signal line, determines the detailed status of the printer, and immediately performs processing (such as paper feeding or When a temporary busy state occurs, such as during a line feed, print data is sent to the output sofa or other time-sharing processing is performed, and when an abnormally busy state occurs, such as when a paper jam or ribbon runs out, an alarm notification is activated. (processing, etc.).

In this embodiment, various busy status signals are output, but printer setting status signals such as paper size, number of lines, number of characters, etc. may also be output, and the contents of the output signals can be set in various ways. .

Also, the signal line used is a busy signal line, but for example, ACK (acknowledge: data reading completion notification)
Other basic signal lines (standard signal lines) such as wires may also be used.

[Effects of the Invention] According to the present invention, it is possible to output the cause of data input prohibition of the printer device, etc. using a standard signal line such as a busy signal line.

Therefore, since the use of signal lines can be unified, there is no need to consider the connection of signal lines with the host device even if the printer models are different, and the printing process does not become complicated.

Furthermore, the reason for inhibiting data input can be output to the host device using one standard signal line, eliminating the need to use multiple status lines.

[Brief explanation of the drawing]

Figure 1 is a block diagram of the present invention, Figure 2 is an internal configuration diagram of the printer, Figure 3 is a diagram showing changes in the Centronics interface signal when paper runs out during printing, and Figure 4 is at the time of a test command. FIG. 3 is a diagram showing changes in the Centronics interface signal of FIG. 1... First signal output means, 2... Second signal output means, 3... Output signal control means.

Claims (1)

[Claims] a first signal output means for notifying whether there is an unreceivable state of data from the host device to the printer device; a second signal output means for notifying the cause of the unreceivable state;
Output signal control means for switching the signals output from the signal output means and the second signal output means and outputting the unreceivable state of the printer device and information about the cause of the unreceivable state to the host device via the same signal line. A printer control device comprising: