JPH0216076A - Printer - Google Patents

Abstract

PURPOSE:To improve the operability of a system without the need for changing the setting of a printer to an assigned interface every time when an operator uses the printer by independently masking a plurality of interface ports when one printer is shared among a plurality of host computers. CONSTITUTION:When a signal 12 for interrupting host computers 2, 3 other than a host computer 1 is generated, mask signals 16, 17 to the host computers 2, 3 are generated to apply an interrupt to interface gates 9, 10. Similarly, if a signal 13 for interrupting the ghost computers other than the host computer 2 is generated, mask signals 15, 17 are generated to apply an interrupt to a gate 8 and the gate 10. In this manner, a printer can receive only the data from the required host computer and cannot receive the other data.

Description

[Detailed description of the invention] Ru.

FIG. 1 shows an embodiment of the present invention.

In FIG. 1, 1, 2.3 are host computers, and interface cables 21, 22,
．． 23 to the three interface ports 5, 6.7 of the printer block 4, respectively.

8.9.10 for each interface port 5
, 6.7 input/output gates are shown, and these gates 8, 9 .
When data is input to each of the gates 8, 9 and 10, interlaced signals 1
2.13.14 notifies the interface controller 11 of such data input.

! 5.16.17 are mask signals, and these mask signals 15.16.17 are sent to input/output gates 8, 9.10,
When input, respectively, interface port 5,
6.7 becomes offline (0FF-LINE).

A data bus 18 connects each output gate 8, 9, 10 and an interface controller 11, and is connected to a system data bus 19 through the interface controller 11. This system data bus 19 is connected to the CPt 120 of this printer block 4.

In this embodiment, a case will be specifically described in which the interface includes, for example, three Centronics I/F ports. The host computers 1, 2.3 are
Turn on the power to the printer while it is connected to the Centronics boards -5, 6, and 7, respectively.

The ROM of the above-mentioned interface controller 11 stores a control procedure as shown in FIG. 2, for example.

This printer performs a predetermined startup operation, and in step Sl shown in the second figure, determines whether or not it is ready for printing and accepting data.When it becomes ready for printing and accepting data, a message appears on the operation panel (not shown). on·
The indicator indicating line J (ON-LINE) is lit to inform the controller 11 that data can be accepted. In step S1, if the data cannot be accepted even after a predetermined period of time has elapsed, the process advances to step S2 to perform error processing and the like.

If it is determined in step 51 that data can be accepted, the process proceeds to step S3, where the controller 11
is for each interface gate 8,9゜10,
In order to notify that reception is possible, reception mask signals 15, 16.
Turn off 17.

Furthermore, in the next step S4, each interface gate 8, 9, 10 notifies the host side that reception is possible using the Centronics protocol.

Next, sequential steps 55. S6. Proceeding to S7, the gate 8,
From 9.10, it is determined whether interlaced signals 12, 13.14 are issued. That is, in step S5, host computers 2.
It is determined whether or not the interlaced signal 12 for interlacing the mask signal 1 to the host computer 2.3 has occurred.
Generate 6.17 and apply interlaced to interface gate 9.10.

When the result in step S5 is negative, the process proceeds to step S6, and it is determined whether or not the interwoven signal 13 for interlapping the host computers 1 and 3 other than the host computer 2 has occurred, and when the result is affirmative, the process proceeds to step S9. Mask signal 15 for host computer 1.3.
17 and interface gate 8. Multiply IO by interloved.

When the result in step S6 is negative, the process proceeds to step S7, where it is determined whether or not the interwoven signal 14 for interlapping the host computer 1.2 other than the host computer 3 has occurred, and when the result is affirmative, the process proceeds to step 510. Mask signal 15 to host computer 1.2
．． 16 and applies an interlaced signal to the interface gate 8.9.

Through the above steps 55 to 510, only data from the necessary host computers is received, and data from other host computers is disabled, and then the process proceeds to step Sll, where normal printing processing begins. This printing process is controlled by the CPO 20 of the printer. When the printing process is completed, a message to that effect (: from PO20 to interface controller 1
1, and the process moves to the next step 512, where all mask signals for other host computers are reset.

Next, a specific example from step S5 onward will be described. For example, when data is transferred from the host computer 1, the interface gate 8 receives the interwoven signal 12 by receiving the data strobe.
is set (step S5), and the controller 11 is notified of the on-line status.

Next, the controller 11 sets the mask signal 18.17 to notify the interface gate 9.10 that reception is not possible (step S8).

Each interface gate 8,9. to makes the Centronics protocol unreceivable, such as by making the select signal negative.

After this, normal printing processing operation is performed (step 511).
), and finally, when the communication is completed, the other interfaces are unmasked (step 512).

(Other Embodiments) In the above embodiments, all Centronics interfaces are used, but the present invention can be similarly applied even if the interfaces are replaced with interfaces of other standards.Alternatively, when interfaces of various standards are mixed. Of course, the present invention can also be applied to.

〔Effect of the invention〕

As is clear from the above, according to the present invention, in a system in which one printer is shared by a plurality of host computers, each time an operator attached to each host computer uses the printer, it is possible to set the printer. Since there is no need to change the interface assigned to the operator's host computer, the operability of the system can be improved.

8.9.10...Interface gate, 11...
・Interface controller, 12, 13.14・
... Interwoven signal, Is, 16.17... Mask signal, 18... Data bus, 19... System data bus, 20... Printer CPU.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an interface portion of an embodiment of the present invention, and FIG. 2 is a flowchart showing an example of its control procedure. 1-3...Host computer, 4...Printer block,

Claims (1)

[Claims] In a printer having a plurality of interface ports for inputting print data, means capable of individually masking each of the interface ports, and means for masking each of the interface ports at all times. 2. A printer comprising: means for setting the interface port in a data-receiving state; and means for masking the remaining interface ports when data is input from one of the interface ports.