JPS63316537A - System for sharing output device - Google Patents

Abstract

PURPOSE:To simplify the control of the processing sequence of respective stacks and to execute the low price without storing the data for an output request stack awaited with the sequence control into an output device side by controlling an output device assignment sequence to the output request stack in accordance with a priority sequence included in the output request. CONSTITUTION:By a coaxial cable 21, plural transceivers TR22-1-22-3 are connected, a printer 25 is connected through a control part 26 to the TR22-3, tasks A'-C' are connected through computers 24-1 and 24-2 to other TR, and the printer 25 is shared by the tasks A'-C'. To the control part 26 of the system, a control table 27 to control the priority of a printing request from the tasks A'-C' is arranged. The request address provided at the table 27 and the priority, and the priority of the request from the tasks A'-C' sent onto the cable 21 by a task name are decided by the control part 26 and the action of the printer 25 is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an output device sharing method in which one output device is shared by a plurality of tasks on a network.

(Prior Art) Output devices, such as printers, are generally configured to print various input data in the order in which they are input (in the order in which they arrive). Figure 6 shows a network system in which this type of printer is connected to a network.
Reference numeral 1 denotes a transmission path configuring the network, for example, a coaxial cable 11.

This coaxial cable 11 includes a transceiver (TR) 12
A computer 13-1.13-2 is connected via -1.12-2, and a printer 14 is connected via a transceiver (TR) 12-3. In the system shown in Figure 6,
The printer 14 performs task A executed by the computer 13-1,
It is shared by task C executed by B and calculation 11113-2.

Assume that the printer 14 is now in a ready state, and in this state, task A requires an output operation of the printer 14. In this case, task A is printer 1
When the ready state of No. 4 is detected, the print data is transferred to the printer 14 via the coaxial cable 11. The printer 14 inputs data from task A as shown in FIG. 7, and prints out the input data. During the above data input/output period, the printer 14 is in a busy state. If the printer 14 is busy, other tasks B and C
Even if printer 14 requires output operation, printer 1
The output of print data (print output) is made to wait until the printer 4 becomes ready. Then, when the printer 14 becomes ready and, for example, task B secures the right to use the coaxial cable 11 first, the print data output from task C will be as follows.
As shown in FIG. 7, it is held until the input/output operation of the printer 14 for the print data from task B is completed.

As mentioned above, in a system in which a printer that prints out data in the order in which it arrives is directly connected to a network and shared by multiple tasks, print output requests from multiple tasks to the printer are processed according to the arrival class. There is a problem in that the processing order (print output order) cannot be controlled. Furthermore, tasks that are forced to wait for print output must constantly monitor the status of the printer.

On the other hand, a method is also known in which the spool function is implemented using a print server. However, this method is expensive, and furthermore, when a normal computer is used as a printer server, there is a problem in that a load is placed only on that computer.

(Problems to be Solved by the Invention) As mentioned above, conventionally, when building a low-cost system in which multiple tasks can share an existing output device such as a printer on a network, It was not possible to control the processing order.

This invention was made in view of the above circumstances, and its purpose is to provide a configuration in which multiple tasks can share an existing output device such as a printer on a network, while simplifying the processing order for output requests from each task. The purpose of this invention is to provide a controllable output device sharing method.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a priority system that indicates the priority of requests for output operation requests to the output device from each task that shares the output device on the network. An output request means for transmitting output request information including the information and the name of the requested task onto the network, and a registration means for receiving the output request information from the output request means and registering the output request of the corresponding task in a management table, Based on the output requests for each task registered in the management table, output devices are assigned in order of priority tasks, and output data is input from the assigned tasks and used for the output operation of the output device. It is something.

(Operation) According to the above configuration, the order in which output devices are assigned to output request tasks can be easily controlled according to the priority included in the output request, and moreover, the order in which output devices are assigned to output request tasks can be easily controlled according to the priority included in the output request. There is no need to store output data on the output device side.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of a network system to which the present invention is applied.

In the figure, 21 is a transmission line that constitutes a network;
For example, coaxial cables, 22-1 to 22-3 are transceivers (TR), and 23-1 to 23-3 are transceivers 22-
It is an input/output interface that is connected to the coaxial cable 21 via cables 1 to 22-3 and performs data input/output with the coaxial cable 21. 24-1 is, for example, task A'.

The calculation Ill, 24-2 with B' is, for example, a computer with task C'. The measuring line machine 24-1.24-2 is connected to the input/output interface 23-1.23-2.

Reference numeral 25 denotes an output device, such as a printer, which is shared by various tasks such as tasks A' to C' existing on the network in FIG. This is the control unit. The control unit 26 has a management table 27 that manages the priorities of print requests from various tasks. Each entry in this management table 27 is used to set print request information indicating print requests from various tasks. As shown in FIG. 2, the print request information set in each entry of this management table 27 includes the task name of the print request task,
It consists of the print request priority and the address of the computer that has the print request task (request source address).

Next, the operation of one embodiment of the present invention will be explained in FIGS. 3 and 4.
This will be explained with reference to the flowchart shown in the figure and the timing chart shown in FIG.

The control unit 26 controls the first entry (first entry) of the management table 27.
It is constantly checked whether print request information is set in the entry (step AI). Now, when the first entry of the management table 27 is empty (in this case, the entire management table 27 is empty as described later), as shown in FIG. It is assumed that print request information indicating a print request to the printer 25 is sent to the coaxial cable 21 via the input/output interface 23-1 and the transceiver 22-1 by calculation 11124-1. The print request information on this coaxial cable 21 is sent to the transceiver 22-3.
, are guided to the control unit 26 via the input/output interface 23-2. When the control unit 26 receives this print request information, it temporarily stores it in a memory (not shown) (step B1).
, checks whether the printout is in progress (step B2>). If the printout is not in progress as in this embodiment, the control unit 26 performs a process of registering the received print request information in the management table 27 ( Step B3) In this embodiment, where the management table 27 is in an empty state, the print request information received (from task A') is registered in the first entry of the management table 27 by the process of step B3. , if some pieces of print request information have already been registered in the management table 27, each priority in the registered print request information is compared with the priority in the newly accepted print request information, and the management table 27 The registered print request information is rearranged and newly accepted print request information is registered so that the order in 27 is in descending order of priority.

Now, when step B3 is executed, the determination in step A1 becomes YES. In this case, the control unit 26 extracts print request information (from task A') registered in the first entry of the management table 27 (step A2).

Next, the control unit 26 sends the computer (computer 24-1 in this case) indicated by the request source address in the print request information extracted in step A2 a request from the task (task A'') indicated by the task name in the same information. A request is made to transfer the print data (step A3). In response to the data transfer request from the control section 26, the computer 24-1 transfers the print data from task A' to the control section 26 as shown in FIG. When the control unit 26 inputs the data from task A' (step A5), it outputs the input data to the printer 25 as shown in FIG. A printout operation using print data is performed.

Now, during the printout requested by task A', the fifth
As shown in the figure, it is assumed that print request information from task B' is sent onto the coaxial cable 21 and accepted by the control section 26. In this case, after temporarily storing the received print request information, the control unit 26 turns on a flag (not shown) to accept the request since it is currently being printed (steps B1, B2, and B4), and returns to the original process. Return to Subsequently, during the above printout, the print request information from task C' is transferred to the coaxial cable 2 as shown in FIG.
1 and received by the control unit 26. In this case, the print request information from task C' is also temporarily stored in the control unit 26.

Eventually, when the printout operation requested by task A' is completed, the control unit 26 moves the contents of each entry after the second entry in the management table 27 to the previous entry (steps A6 and A7). . As a result, in this embodiment, where each entry after the second entry is empty, the contents of the first entry are also cleared, and the entire management table 27 becomes empty. After executing step A7, the v1m unit 26 checks whether the request acceptance flag is on (step A8). As in this embodiment, if the flag is on, the request reception proceeds to step A9 described below, and if the flag is off, the process returns to step A1.

In step 80, based on the priority in the print request information (from tasks B' and C') temporarily saved in step B1 of FIG. 4, the information is registered in the management table 27. will be carried out. Here, assuming that the priority of the print output request from task C' is higher than that from task B', if the management table 27 is in an empty state as in this embodiment, the above In step A9, the print request information from task C' is registered in the first entry of the management table 27, and the print request information from task B' (which was requested before task C') is registered in the second entry of the management table 27. registered in the entry. Note that if some pieces of print request information have already been registered in the management table 27, each priority in the registered print request information is compared with each priority in the temporarily stored print request information, The registered print request information is rearranged and the temporarily stored print request information is registered so that the management table 27 is arranged in descending order of priority.

When the control unit 26 executes step A9, the request acceptance flag is turned off and the process returns to step A10> and step A1.

In this case, since the print request information is registered in the management table 27 in step A9, the determination in step A1 is always YES. If the determination in step A1 is YES, the control unit 26 controls the transfer of print data from the task C' to the computer 24 based on the print request information from the task C' registered in the first entry of the management table 21. -1 (Step A2
, A3). As a result, as shown in FIG. 5, when the print data from task C' is transferred to the M8F 426, the control section 26 inputs the same data and outputs it to the printer 25 (steps A4 and A5). As a result, the print request for task C' issued after task B' is executed first.

When the print output operation requested by task C' is eventually completed, the print request information from task B' that was registered in the second entry of the management table 27 is moved to the first entry of the management table 27 (step A6,
A7). Then, after step A8 and AI, the process from step A2D is performed again, and this time task B'
A request is made to transfer the print data from task B', and the print data transferred from task B' in response to the request is passed to the printer 25 and printed out.

In the above embodiment, the priority was set in the print request information from each task.
This priority may be predetermined for each task, or may be changed as appropriate depending on the urgency of print output. Furthermore, instead of the priority itself, it is also possible to use information that indirectly indicates the priority. For example, it is also possible to set the size of print data in the print request information instead of the priority, and give priority to printing out large-sized data.

Further, in the above embodiment, a case has been described in which a plurality of tasks share a printer on a network, but the present invention can be similarly applied to a case where an output device other than a printer, such as a plotter for drawing, is shared.

[Effects of the Invention] As described in detail above, according to the present invention, the following effects can be achieved.

(2) Although the configuration allows multiple tasks to share an existing output device such as a printer on a network, the processing order of output requests from each task can be controlled easily and at low cost.

■ Since it is not necessary to store the output data of the output request task held for controlling the processing order on the output device side, the spool function is realized without preparing a disk device or large capacity memory on the output device side. can.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a network system to which the present invention is applied, FIG. 2 is a diagram showing the structure of the management table shown in FIG. 1, and FIGS. 3 and 4 explain the operation. 5 is a timing chart for explaining the operation, FIG. 6 is a block diagram showing a conventional example, and FIG. 7 is a timing chart for explaining the conventional operation. 21... Coaxial cable, 24-1.24-2... Computer, 25... Printer, 26... Control unit, 27.
...Management table. A'~C'...Tasks.

Claims (1)

[Claims] In a network system in which one output device is shared by multiple tasks on a network, a management table for managing the priority of output operation requests from each task to the output device, and an output operation request from the task to the output device. For this purpose, output request means sends output request information including priority information indicating the priority of the request and the requested task name onto the network, and output request means receives the output request information from the output request means and outputs the corresponding task. comprising a registration means for registering a request in the management table, and a control means for allocating the output device to the task in order of priority based on the output request for each task registered in the management table, An output device sharing system characterized in that the control means inputs output data from a task to which the output device is assigned and provides it for the output operation of the output device.