JP3327312B2 - Print server - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print server in a computer network system in which a plurality of host computers share a printer via a network.

[0002]

2. Description of the Related Art In general, there is known a computer network system in which a plurality of host computers and a printer are connected via a network, and the plurality of host computers can share and use the printer. Conventionally, this type of system is configured such that when a plurality of host computers generate print permission requests, print permission is given in the order of generation.

[0003]

By the way, in such a system, there are cases where a plurality of host computers should be used with higher priority than others due to the nature of the processing task. For example, among a plurality of host computers used in a certain business establishment, a host computer for a certain department (or a certain business) can preferentially use a printer over a host computer for another department (or another business). There are cases where it is preferable.

[0004] However, in the conventional system, when a plurality of host computers generate print requests, the print permission is given in the order in which the requests are generated. .

The present invention has been made in view of the above-mentioned conventional problems, and in a computer network system in which a plurality of host computers share a printer via a network, one host computer can preferentially use a printer over another host computer. It is an object to provide a print server convenient for a user.

Another object of the present invention is to provide a convenient print server capable of adaptively changing the priority for giving print permission according to the frequency of use.

[0007]

Means for Solving the Problems In order to achieve the above object, the present invention has a plurality of protocol units for identifying print requests having different communication protocols, and any one of the plurality of protocol units identifies a print request. And an arbitrator for permitting the print request based on the priority of each communication protocol when two or more of the protocol units identify the print request during the standby time.

[0008] The use time of the printer may be integrated for each communication protocol, and the priority of a communication protocol having a long integration time may be lowered. In this case, the weight for the integrated time for each communication protocol may be settable by the user.

The priority for each communication protocol may be fixedly set by the user.

[0010]

According to the present invention, when a print request is issued from two or more protocol units within a predetermined time, the print request is permitted based on the priority of each communication protocol. In a computer network system sharing a printer, it is possible to realize a print server that is convenient for a user who can use a printer preferentially over one host computer over another host computer.

[0011] Further, by accumulating the usage time of the printer and lowering the priority of the communication protocol having a long integration time, the priority for giving print permission can be adaptively changed according to the frequency of use. Therefore, it is possible to prevent a case where a specific protocol occupies the printer for a long time and another protocol cannot use the printer. In this case, a print server that is more convenient for the user can be realized by allowing the user to set the weight for the integrated time for each communication protocol.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a computer network system to which a print server according to the present invention is applied, FIG. 2 is a block diagram showing the configuration of the print server in FIG. 1 in detail, and FIG. FIG. 4 is a flowchart for explaining the operation of the protocol unit, and FIG. 4 is a flowchart for explaining the operation of the arbitrator of FIG.

In the system shown in FIG. 1, one printer 1, a plurality of personal computers (hereinafter, referred to as clients) 2 to 5 sharing the printer 1, and a first printer 1 for temporarily storing print data are provided. File server 6 and a network communication medium 7 such as Ethernet
Connected through.

The printer 1 has a print server 8. The print server 8 provides a communication interface between the printer 1 and the communication medium 7. As a basic function, the print server 8 receives print data from the clients 2 to 5 and the file server 6 according to a predetermined communication protocol.
It has a function of transferring this to the printer 1. It should be noted that the print server 8 may be either a built-in type or an external type in the printer 1.

In the present embodiment, the clients 2 to 5
Two different models, ie, clients 2 and 3 are models that use the first communication protocol, and client 4
Is a model that uses the second communication protocol, and the client 5 is a model that uses the third communication protocol.

In a practical example, the first communication protocol is SPX / IPX used by Novell NetWare, for example.
The second communication protocol is, for example, Maci of Apple Computer
This is AppleTalk of ntosh, and the third communication protocol is, for example, TCP / IP. This is merely an example, and other communication protocols may be used.

As described above, the clients 2 to 5 can be divided into a group of models using three different protocols. These protocols have the following features.

(1) In any of the protocols, the communication method is packet communication.

(2) Any protocol can recognize a print request from the contents of a packet.

(3) With any protocol, the type of protocol can be identified from the format or content of the packet.

(4) First protocol (for example, NetWare S
The print data from the clients 2 and 3 (PX / IPX) is first stored in the file server 6 and then read from the file server 6 to the print server 8. Print data from the clients 4 and 5 of the second and third protocols (for example, AppleTalk and TCP / IP) is directly received by the print server 8 without passing through the file server 6.

Next, the configuration of the print server 8 will be described in detail with reference to FIG. The packet transmitting / receiving unit 11 transmits packets of print data and various control data (for example, control data relating to reading of print data from the file server 6 and handshaking with the clients 4, 5 and the file server 6) through the network 7. It transmits and receives to and from the file server 6 and the clients 4 and 5. Packet transmission timing control and the like are also performed by the packet transmission / reception unit 11. The packet discriminating unit 12 transmits the packet received from the network 7 to the packet transmitting / receiving unit 1
1 to determine which protocol the received packet belongs to, and pass it to the corresponding one of the three protocol units 13, 14, and 15.

The protocol units 13, 14 and 15 perform packet communication operations on the network 7 in the first
Execute according to the protocol, the second protocol and the third protocol. Each of the protocol units 13, 14, and 15 can recognize the print request from the contents of the packet passed from the packet discrimination unit 12, and when recognizing the print request, first, the printer 1 determines whether the printer 1 is normal or not. After confirming that the inquiry is normal, a print permission request is issued to the arbitrator 16. Then, upon receiving a print permission from the arbitrator 16, the printer 1 subsequently sends the print data received via the network to the printer 1.

The arbitrator 16 has a protocol unit 13,
When the first print permission request is received from one of the printers 14 and 15, the printer 1 shifts to the arbitration mode for a fixed time without giving print permission even when the printer 1 is not printing. During this mode, the other protocol units 1
When a print permission request is received from 3, 14, and 15, the highest priority is given to all print permission requests received during the arbitration mode. One of them is given a print permission, and the others are rejected. Then, when the permitted printing is completed, one of the print non-permissions having the highest priority is selected and a print permission is issued, and a print permission request is received in the order of priority in this manner.

Here, the priority of each protocol may be fixedly set by the user. In this case, however, there are too many opportunities for a specific protocol to occupy the printer 1, and other protocols use the printer 1. It may not be possible to use it. Therefore, by automatically changing the priority of each protocol according to the frequency of use of each protocol, print requests of a plurality of protocols can be processed harmoniously. For example, the printer use time of each protocol is integrated, and the priority is calculated by the following equation: priority = integration time / weighting coefficient (1) based on the integrated time and the weighting coefficient of each protocol set in advance. In other words, as the weighting coefficient increases, the priority value decreases (= priority increases), and if the integration time of the past printer usage time increases,
The priority is automatically changed so that the value of the priority becomes large (= the priority is low).

The clock section 17 counts the time required for each printing process to calculate the equation (1), and the counted time is passed to the arbitrator 16. The arbitrator 16 accumulates the measured time for each protocol, and automatically changes the priority of each protocol based on equation (1).

Next, referring to FIG.
Operations 14 and 15 will be described. Protocol section 13, 1
Each of 4 and 15 monitors a print request on the network 7 with each protocol i (i = 0, 1,...) In step S1, and when a print request is detected, proceeds to step S2 and subsequent steps. In step S2, it is checked whether or not the printer 1 is normal. If YES, the process proceeds to step S3. On the other hand, if NO, the process branches to step S7 to send an error signal back to the transmission source. Error processing of the request is performed, and the process returns to step S1.

In step S3, a print permission request is sent to the arbitrator 16, and a response from the arbitrator 16 is waited.
If a response to print permission is received from step 6, step S
If the answer is NO, the process branches to step S8 to send a busy signal back to the transmission source to execute a busy process for the print request, and returns to step S1.

In step S5, the print data is sent to the printer 1. When the sending of all the print data is completed, in step S6, the end of printing is notified to the arbitrator 16, and the process returns to step S1.

Next, referring to FIG.
Will be described. First, if a print permission request is not received in step S11 and the arbitration mode is not currently in progress in step S16, the process stands by in a loop of steps S11 → S16 → S11. In this standby state, in step S11, the protocol unit 1
If a print permission request has been received from any of 3, 14, and 15, the process branches to step S12 and below, and if not, the process proceeds to step S16 and below.

When a print permission request is received, first, the print permission request is registered in the memory, and it is determined whether or not print permission has already been given to another protocol unit (step S12). If the print permission is given, the protocol section that has received the print permission request in step S11 is notified of print non-permission (step S13), and returns to step S11.

On the other hand, if the print permission is not given to the other protocol units in step S12,
It is determined whether or not the current mode is the arbitration mode (step S14). If YES, step S11 is performed.
Return to On the other hand, if NO in step S14, the mode shifts to the arbitration mode, starts measuring a predetermined waiting time (step S15), and returns to step S11. That is, when a print permission request is first received in the standby state, the printer shifts to the arbitration mode and maintains the arbitration mode for a predetermined waiting time.

Here, the predetermined waiting time in the arbitration mode refers to whether or not the next request comes after receiving the first print permission request, and permits one of the plurality of print permission requests. The arbitration time is set to an appropriate time that is long enough to accept a plurality of print permission requests that have occurred consecutively and that is not long enough to affect the operation of the entire system. Have been.

Once in the arbitration mode, if a subsequent print permission request is received in step S11, the request is registered and the process returns to step S11, and if no subsequent print permission request is received, the process proceeds to step S17. It is determined whether or not a predetermined waiting time in the advance arbitration mode has ended, and if NO, the process returns to step S11.

When the predetermined waiting time in the arbitration mode ends in step S17, the process proceeds to step S18, where the protocol unit i having the highest priority is selected from the protocol units that have received the print permission request during the arbitration mode (step S17). S18), and print permission is notified to the selected protocol unit i (step S18).
19), and then notify the other protocol units participating in the arbitration of the print rejection (step S).
20) Then, the clock unit 17 starts measuring the print time of the protocol unit i that has permitted the printing (step S21).

In the following step S22, the printing of the protocol section i is waited for, and when it is finished, the process proceeds to step S23. In step S23, the clock unit 17 terminates the counting of the print time of the protocol unit i, accumulates the counted time, and calculates and stores the priority (= integrated time / weighting coefficient) for each protocol. In the following step S24, if there is another protocol received during the arbitration mode, the flow returns to step S18 to give permission to the protocol having the next highest priority, while if NO, the flow returns to step S11.

As described above, when there are a plurality of clients using different protocols, the priority is determined for each protocol, and when the print requests of the plurality of clients compete within a fixed short time, the priority is determined. The print requests from those clients are accepted in descending order. Therefore, if you distinguish client protocols according to the importance of business at offices, etc.,
Print requests for important tasks will be accepted prior to other tasks. Further, the priority for giving print permission can be adaptively changed according to the frequency of use. As a result, it is possible to smoothly perform the business processing of the entire business establishment.

[0038]

As described above, according to the present invention, in a computer network system in which a plurality of host computers share a printer via a network, one host computer gives priority to a printer over another host computer. It is possible to realize a print server that is convenient for a user who can use the print server.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a computer network system to which a print server according to the present invention is applied.

FIG. 2 is a block diagram showing the configuration of the print server of FIG. 1 in detail.

FIG. 3 is a flowchart illustrating an operation of a protocol unit in FIG. 2;

FIG. 4 is a flowchart for explaining the operation of the arbitrator of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printer 2-5 Host computer (client) 7 Network 8 Print server 13-15 Protocol part 16 Arbitrator 17 Clock part

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-103186 (JP, A) JP-A-4-253222 (JP, A) JP-A-2-113327 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G06F 3/12

Claims (11)

(57) [Claims] A plurality of protocol units for identifying respective print requests having different communication protocols; and a wait for a predetermined time when any of the plurality of protocol units identifies the print request, and the protocol unit for the waiting time. And an arbitrator for permitting the print request based on the priority of each communication protocol when two or more of the print requests are identified. 2. The communication system according to claim 1, wherein said arbitrator is a communication protocol.
Change the priority of each communication protocol according to the usage frequency of the file
The print server according to claim 1, wherein 3. The communication system according to claim 1, further comprising: a timer for counting the usage time of the printer for each communication protocol, wherein the arbitrator integrates the usage time calculated by the timer for each communication protocol, and the communication protocol having a long integration time. 3. The print server according to claim 1, wherein the priority of the print server is reduced. 4. The print server according to claim 3, wherein the user can set a weight for the integrated time for each communication protocol. 5. The print server according to claim 1, wherein a priority for each communication protocol can be set by a user. 6. A protocol unit for identifying a print request from a host computer for each communication protocol, and a standby for a predetermined time when the protocol unit identifies a print request of a first communication protocol. An arbitrator for selecting a print request based on the priority of each communication protocol when the unit identifies a print request of the second communication protocol. 7. The print server according to claim 6, wherein the arbitrator changes the priority of each communication protocol according to the frequency of use of each communication protocol. 8. An arbitrator for counting the use time of the printer for each communication protocol, wherein the arbitrator integrates the use time calculated by the time counting means for each communication protocol, and the communication protocol having a long integration time. 8. The print server according to claim 6, wherein the priority of the print server is reduced. 9. The print server according to claim 8, wherein a weight of the integrated time for each communication protocol can be set by a user. 10. The print server according to claim 6, wherein a priority for each communication protocol can be set by a user. 11. A method of operating a print server connected to a network and providing a communication interface to a printer, comprising: an identification step of identifying each print request having a different communication protocol; and a wait for a predetermined time when the print request is identified. And a permitting step of permitting the print request based on the priority of each communication protocol when a print request having two or more different communication protocols is identified during the waiting time.