JP3754930B2 - Printer and printer system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printer including a USB interface and a printer system including the printer.
[0002]
[Prior art]
Due to advances in network technology and the need for higher processing speeds, a single printer system is built by interconnecting multiple printers, with the primary purpose of speeding up load distribution and parallel processing, and a specific host PC (personal computer) A printer system that is controlled from a server is used.
[0003]
On the other hand, the USB (Universal Serial BUS) standard is frequently used for an interface (hereinafter simply referred to as “I / F”) for connecting a host PC and peripheral devices. This USB is a standard established as a communication I / F between a personal computer and peripheral devices. In USB, data transfer is performed under the initiative of the host PC, and peripheral devices transmit and receive data in response to requests from the host PC.
[0004]
A printer system using a plurality of printers using USB is proposed in Japanese Patent Laid-Open No. 2001-075764.
[0005]
Japanese Patent Laid-Open No. 2000-155654 discloses a technique for causing a connected printer group to perform distributed printing when printing of a plurality of copies is instructed.
[0006]
[Problems to be solved by the invention]
However, when the host PC and printer are connected via the USB interface, it is possible to control each printer of the printer system and one host PC by connecting them via USB via a hub. In addition, the length of the USB cable that can be directly connected to the printer is limited, and the system configuration is complicated, which is not practical.
[0007]
Therefore, instead of transferring data from the host PC to each printer, it is desired to be able to transfer data directly between printers. However, in the technology disclosed in Japanese Patent Laid-Open No. 2001-075764, the host PC takes the lead in data transfer. There is a problem that it is necessary to control and is not suitable for transferring data between printers.
[0008]
In addition, the technique disclosed in Japanese Patent Laid-Open No. 2000-155654 has a problem that each printer cannot be controlled as a USB printer from a host computer.
[0009]
An object of the present invention is to provide a simple system configuration for performing print control from a host computer as a USB printer for a plurality of printers having no USB function even if not all printers in the printer system have a USB function. This is realized by simple control on the host computer side.
[0010]
Another object of the present invention is to dynamically reconfigure the configuration of a plurality of printers so that a flexible printer system can be used.
[0011]
[Means for Solving the Problems]
The invention described in claim 1 is a printer having a USB (Universal Serial BUS) interface that can be communicably connected to a host computer, and addresses on the USB system for other printers connected to the printer. And a first table that registers the actual address in association with each other, and a reception unit that receives a request output from the host computer to the other printer by designating an address on the USB system And when there is a print request by designating an address on the USB system to the other printer from the host computer, the address on the USB system is referred to by referring to the first table. Is converted into an actual address, and the other printer indicated by the address is made to execute the print request. A printer characterized in that it comprises a printing means.
[0012]
Therefore, when a printer system is constructed in which this printer is connected to another printer and a host computer is connected to this printer, this printer replaces the other printer even if the other printer does not have a USB function. The printer responds to the host computer, and even if a print request is made from the host computer to another printer with an address on the USB system, the printer determines the actual address of the other printer and makes a print request. Printing control from a host computer as a USB printer can be realized by a simple system configuration and simple control on the host computer side.
[0013]
According to a second aspect of the present invention, in the printer according to the first aspect, instead of the first table, an address on the USB system and a plurality of other devices connected to the printer and not equipped with a USB interface are provided. A second table in which printers are grouped and printer groups that identify the groups are associated and registered, and the other printers belonging to the groups identified by the printer groups and the printer groups A third table that registers and associates actual addresses with the printer, and the printing means designates addresses on the USB system from the host computer to the other printers. When there is a print request, refer to the second and third tables, and on the USB system. Thereby executing the print request to the other printers in the group that corresponds to the address, characterized by.
[0014]
Therefore, since each printer can be grouped and the printers belonging to each group can be operated from the host computer side as if they were each a single USB device, a flexible printer system can be used.
[0015]
According to a third aspect of the present invention, in the printer according to the second aspect, the printing unit makes a print request by designating an address on the USB system from the host computer to the other printer. When the second and third tables are referred, an inquiry is made as to whether other printers belonging to the group corresponding to the address on the USB system can execute printing, and printing is possible. The print request is executed to another printer.
[0016]
Therefore, a flexible printer system can be used by causing a printable printer among the printers belonging to the specified group to execute printing.
[0017]
According to a fourth aspect of the present invention, in the printer according to the third aspect, when the print request is executed with respect to the other printable printer, it is determined which printer has actually executed the print request. It has a notification means for notifying the host computer.
[0018]
Accordingly, the user who has requested printing can know from which printer the print output is made.
[0019]
According to a fifth aspect of the present invention, in the printer according to the second or third aspect, the group configuration change request is received from the host computer and the second and third tables are registered in accordance with the request. It is characterized by comprising changing means for changing the contents.
[0020]
Therefore, the registration of the group configuration can be dynamically reorganized, so that a flexible printer system can be used.
[0021]
According to a sixth aspect of the present invention, in a printer system configured by connecting a plurality of printers connected to each other and a host computer, at least one of the plurality of printers is any one of the first to fifth aspects. A printer system according to claim 1.
[0022]
Therefore, there exists an effect | action similar to the invention as described in any one of Claims 1-5, and an effect.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described.
[0024]
[About USB]
First, the USB standard will be described.
[0025]
Revision 1.1 of the USB standard defines two communication speeds, LS (Low-Speed 1.5 Mbps) and FS (Full-Speed 12 Mbps), and Revision 2.0 newly defines HS (High-Speed 480 Mbps). It was done.
[0026]
As for the transfer mode, information on peripheral devices is notified to the host PC or “control transfer” for receiving a configuration change, “isochronous transfer” that does not perform transfer error control but guarantees the transfer bandwidth, transfer band There are four types: “bulk transfer” that does not guarantee the width but performs error control, and “interrupt transfer” that transfers a small amount of data at a low speed at regular intervals.
[0027]
In USB, a plurality of peripheral devices bus-connected to a host PC via a hub are given a USB address to each including the hub by the host PC. In the USB specification, addresses from 0 to 127 can be recognized, and address 0 is a special address in the initial state at the time of activation.
[0028]
Each peripheral device has a plurality of communication endpoints in the USB system called “end points”. Of these, the endpoint 0 is a special endpoint for notifying the host PC of device information (called “descriptor”) or receiving a descriptor change from the host PC (for control transfer). Always have. Other endpoint configurations differ depending on the device. For example, in the case of a USB printer, an end point for receiving print data from the host PC and an end point for returning a status are separately provided. In USB, an endpoint configuration and descriptor contents corresponding to a device type called “device class” are defined, and consideration is given so that the host PC can handle the same device type uniformly.
[0029]
An outline of USB operation will be described with reference to the communication sequence diagram of FIG. In FIG. 1, detailed handshaking (ACK / NAK etc.) is omitted, and only an outline of transfer is shown. The process in which the host PC recognizes a device connected via USB, assigns an address, and puts the device into an operating state is called “enumeration”. When the host PC detects the connection of the device based on the signal state of the bus, the host PC resets the bus and notifies the device of the start of enumeration. Subsequently, control transfer for obtaining device information starts. Specifically, a “Get_Descriptor” request is transmitted to the device, and the device returns the specified descriptor to the host PC. As a result, the host PC knows the identity of the connected device, so that the corresponding device driver can be activated. The host PC gives a free address to this device by “Set_Address”, and will communicate with this device through this address in the future.
[0030]
In addition, the device is actually put into operation by a command from the host PC such as “Set_Descriptor” or “Set_Configuration”.
[0031]
Regarding the expansion of the number of USB devices, the USB is characterized in that the bus is expanded in a tree shape via a hub. The hub broadcasts a packet from the host PC side to a plurality of devices connected to the device side port, and notifies the host PC of the packet from the device via the host PC side port.
[0032]
Next, a flow of recognizing a hub and devices connected to the hub will be described with reference to the communication sequence diagram of FIG.
[0033]
The hub is also treated as one of the USB devices when viewed from the host PC. In a system in which a plurality of devices are connected to a hub, enumeration for the hub is first executed, and enumeration of the connected devices is sequentially executed after the function as the hub is enabled. Specifically, for each device-side port of the hub, the port status is changed when the device is connected, and this port status is returned in response to a status request periodically issued from the host PC. The transfer speed is determined at the time of connection between the hub and the device. The host PC detects that the port status has changed, and performs new enumeration if the device is newly connected, and invalidates the device if the device is removed. After enumeration, data between the device connected to the hub and the host PC passes through the hub.
[0034]
Embodiment 1 of the Invention
One embodiment will be described as a first embodiment of the invention.
[0035]
FIG. 3 is a block diagram showing the overall configuration of the printer system 1. As shown in FIG. 3, in the printer system 1, a plurality of printers 2 are connected by an inter-printer I / F bus 4 via an inter-printer interface (I / F) 3. One printer 2 in the printer 2 group is connected to a host PC 6 which is a host computer via a USB cable 7 via a USB I / F 5. Each printer 2 connected by the inter-printer I / F 3 has a unique address, and communication between the printers 2 is based on the premise that data can be transferred to a predetermined destination using this address.
[0036]
As shown in FIG. 4, each printer 2 includes various I / Fs 11 such as an inter-printer I / F 3, and controls the various I / Fs 5 and the image data from the controller 12. And a plotter 13 for printing out.
[0037]
FIG. 5 is a block diagram showing electrical connections inside the controller 12. The controller 12 performs I / F control and image processing functions by software and hardware. The controller 12 includes a processor 21 that performs various calculations and centrally controls each unit of the printer 2, a ROM 22, and a RAM 23. Further, in order to control various I / Fs 11, I / F controllers 24 corresponding to the respective I / Fs 11 are provided, and a DMA controller (DMAC) 25 is used to transfer data from the I / Fs to the RAM 23 without going through the processor 21. It has.
[0038]
The image processing unit 26 processes image data in RAM-to-RAM and performs processing such as encoding and expansion processing. The processor 21 side, the RAM 23 side, and the plotter 13 (its plotter I / F 26) side are also provided with I / F controllers 27 to 29 for controlling respective I / Fs, and internal registers of the I / F controller 24 and the DMAC 25 by software. A PIO controller 30 is provided at the tip of the processor bus controller 27. Various I / Fs 11 may or may not be necessary depending on the user, so that each module can be attached and detached as an option.
[0039]
As a flow of printing by the printer 2, print data received from various I / Fs 11 is written to the RAM 23 via the DMAC 25, subjected to RAM-to-RAM image processing, etc., and then again to the plotter I / F 26 by the DMAC 25. And print it out. It is also possible to exchange commands and status between the printers 2 and transfer print data via the inter-printer I / F 3.
[0040]
FIG. 6 is a block diagram showing an electrical connection of the USB I / F controller 31 that controls the USB I / F 5 as the I / F controller 24.
[0041]
The USB data line is a D + / D− serial differential signal. The USB physical layer 32 converts this signal from serial data to parallel when receiving, and conversely converts parallel data from serial to output when transmitting. To do. Processing related to the connection speed is also performed by the USB physical layer 32. The protocol processing unit 33 connected to the USB physical layer 32 performs USB protocol handshaking (for example, ACK handshaking or NAK handshaking for a request, or retransmission of data). The transfer address and end point from the host PC 6 are also detected by the protocol processing unit 33, responding only to a request addressed to its own USB address, and sending or receiving the data of the corresponding end point. The protocol processing unit 33 is connected to internal buffers 34 and 35 for transmission and reception. In response to a request from the host PC 6, data from the host PC 6 is stored in the internal buffer 34 for reception and sent to the host PC 6. Are stored in the internal buffer 35 for transmission.
[0042]
These internal buffers 34 and 35 are connected to an inter-printer I / F control unit 36, a DMACI / F control unit 37, and a processor I / F control unit 38, and distribute data to other printers 2 and other printers. Data reception from 2 is performed via these buffer internals 34 and 35. Further, the software on the other printer 2 side receives the internal buffers 34 and 35 via the DMACI / F 39 that is an I / F with the DMAC 25 and the processor I / F 40 that is an I / F with the processor 21. It is also possible to access. A control status register 45 that stores a control status is connected to the processor I / F control unit 38.
[0043]
The first table, the USB address printer address conversion table 41, stores the address of each printer 2 on the USB system in association with the address of the actual printer system 1 of each printer 2, and stores the USB system. It is a table composed of a RAM or the like that converts the address of the printer 2 above into an address in the actual printer system 1 of the printer 2. Since address assignment on the USB system is not uniquely determined every time due to a device connected to the host PC 6 other than the printer 2 being involved, it is necessary to associate the USB address with the address of each printer 2 every time the system is activated. is there.
[0044]
The initial state of the printer system 1 is a state in which the printer 2 having the USB I / F 5 (hereinafter, the printer 2 having the USB I / F 5 is referred to as another printer 2 and is referred to as a printer 2a) is not connected to the host PC 6. It is. First, the flow from connecting the printer 2a in the printer system 1 to which power is turned on to the host PC 6 to execute enumeration and recognizing it as a device is shown in the communication sequence diagram of FIG. 7 and the block of FIG. This will be described with reference to the drawings. The outline from speed determination to enumeration is as described above with reference to FIG.
[0045]
First, on the host PC 6 side, the cable connection is detected based on the electrical characteristics defined by the USB specification. Thereafter, the transfer rate (LS / FS / HS) is determined by negotiation with the device side.
[0046]
Subsequently, the host PC 6 requests the printer 2a to output a device descriptor describing the features of the USB device.
[0047]
In response to this, the printer 2a returns a descriptor as a printer device to the host PC 6 (the USB I / F controller 31 sends the descriptor to the internal buffer 34 for transmission via the DMACI / F 39 or the processor I / F 40). By recording, when the host PC 6 makes a request, the protocol processing unit 33 reads the data from the internal buffer 34 in response to this, passes it to the USB physical layer 32, and outputs it to the USB cable 7). In order to make the other printers 2 group of the printer system 1 appear as USB devices, the printer 2a responsible for the connection of the printer returns a descriptor as a USB hub prior to the descriptor of the printer device.
[0048]
This processing is automatically executed by the protocol processing unit 33. First, after the host PC 6 is recognized as a USB hub, the protocol processing unit 33 notifies the host PC 6 of the status that the device is connected as a function of the hub so that the host PC 6 can be seen as if the printer device is connected. To do.
[0049]
The flow of device connection notification is as described above with reference to FIG. The host PC 6 interprets that a new device is connected to the hub, attempts to enumerate this device, and requests a descriptor. In response to this request, the printer 2a responds with a descriptor as a printer device, which is recognized by the host PC 6 as a hub and a printer device connected thereto. In this state, since there is only one USB printer, when the host PC 6 performs printing, only the printer 2a connected via USB receives print data and executes printing.
[0050]
In the following, the flow from when the other printer 2 of the printer system 1 is shown to the host PC 6 like a USB device and printed by this printer 2 will be described.
[0051]
That is, the printer 2a connected to the host PC 6 by USB notifies the host PC 6 of the status that a new device has been connected by the operation as the hub following the above-described operation, and responds to the descriptor request from the host PC 6. Then, the operation of returning the descriptor as the printer device is repeated for the number of other printers 2 in the printer system 1 (the communication exchange between the host PC 6 and the printer 2a is as shown in FIG. 7). The other printer 2 is recognized by being assigned a USB device address from the host PC 6 as a printer connected by USB.
[0052]
In the USB I / F controller, every time a new USB address is assigned to the printer 2 including the printer 2a, the association in the USB address printer address conversion table 41 is updated (for example, the printer 2a has the USB address 2 and other printers). One of the two has a USB address 5, etc.).
[0053]
At the time of printing, print data is transmitted from the host PC 6 to the printer 2a connected by USB. The printer 2a accepts it with the internal buffer 35. The printer 2a determines which printer 2 in the printer system 1 is the data addressed to the USB device address of the print data by looking up the USB address printer address conversion table 41, and uses the data addressed to the printer 2a. If not, the data is transferred to the predetermined printer address via the inter-printer I / F 3. The printer 2 that has received the print data via the inter-printer I / F 3 executes printing. With this process, a receiving unit and a printing unit are realized.
[0054]
Before transferring the print data, the printer 2a inquires whether the destination printer 2 can print. If printing is possible, the print data is transferred to the destination printer 2 as described above. However, if printing is already being performed or printing is not possible due to a trouble, the data is transferred to another printable printer 2. Then, transfer printing is executed.
[0055]
In the printing operation, normally, after the print data is transferred, a status is returned from the printer 2a side to the host PC 6 side. The printer 2 that has actually performed printing returns a print execution result to the printer 2a via the inter-printer I / F 3 regardless of whether the printing is normal or abnormal. During this time, the host PC 6 urges the printer 2a to return a status on the USB (specifically, an IN transfer request). However, until the status is returned from the printer 2 that has executed printing, the printer 2a does not return to the host PC 6a. A NAK response (indicating that transfer is not ready yet) is made, and when the status is returned, status data is returned to the host PC 6 via the USB. If the printer 2 requested by the host PC 6 cannot perform printing and transfer printing is performed as described above, the status information includes the information of the printer 2 that actually performed the printing operation, so that the printer of the host PC 6 The application can notify the result to the user.
[0056]
The printer 2a separates the internal buffers 34 and 35 for transmission / reception (configured by a RAM or the like) for each printer 2 in order to correctly process print data and status requests addressed to a plurality of printers 2 that come and go. Used for.
[0057]
The USB address printer address conversion table 41 can be rewritten via the processor I / F 40 (excluding the USB address portion), and the printer 2 corresponding to the already assigned USB address is switched to another printer 2. (For example, the printer 2 with the USB address 5 is switched to another printer 2).
[0058]
[Embodiment 2 of the Invention]
Another embodiment will be described as a second embodiment of the invention.
[0059]
In the following, the description will focus on the differences from the case of the first embodiment, the same reference numerals are used for the circuit elements and the like similar to those of the first embodiment of the invention, and the detailed description is omitted.
[0060]
In the first embodiment, there is a one-to-one correspondence between the USB address and the actual printer 2, but in this second embodiment, a plurality of printers 2 are shown to the host PC 6 as if they were one printer. Causes a printing operation to be performed.
[0061]
FIG. 8 is a block diagram showing an electrical connection of the USB I / F controller 31 used in the printer 2a of the second embodiment.
[0062]
The USB I / F controller 31 includes a printer group table 42 as a second table in addition to the configuration of the USB I / F controller 31 in the first embodiment. In the printer group table 42, a group number and an address group of each printer 2 are registered in association with each other. Actually, a list in which a group number and a list of addresses of the printer 2 are enumerated using a RAM or the like (for example, the group 1 is the printer 2 of the address 2 and the address 3, the group 2 is the printer 2 a and the printer 2 of the address 2 is used The embedded software on the printer 2 side can be set via the processor I / F 40. Instead of the USB address printer address conversion table 41, a USB address printer group conversion table 43, which is a third table in which USB addresses and printer group numbers are registered in association with each other, is prepared.
[0063]
First, the flow of causing the host PC 6 to recognize the printer system 1 is basically the same as that in the first embodiment. However, as a USB device, connection notification is made to the host PC 6 by the number of groups instead of the number of printers 2. To do.
[0064]
Accordingly, since the print data from the host PC 6 becomes print data addressed to the printer group, the USB I / F controller 31 converts the USB address into the printer group by the USB address printer group conversion table 43, and each printer in the printer group. 2 is inquired through the inter-printer I / F 3 whether or not printing is possible, and print data is transferred to the printable printer 2. This implements a printing means.
[0065]
Information indicating which printer 2 is actually output is added to the status so that the printer application of the host PC 6 can notify the user of the printer 2 that has been printed out. This realizes the notification means.
[0066]
Embodiment 3 of the Invention
Another embodiment will be described as a third embodiment of the invention.
[0067]
In the following description, differences from the case of the second embodiment will be mainly described, and the same reference numerals will be used for circuit elements and the like similar to those of the first embodiment of the invention, and detailed description thereof will be omitted.
[0068]
In contrast to the USB I / F controller 31 that allows a plurality of printers 2 in the printer system 1 of the second embodiment to be viewed as one USB device on the USB system, in this third embodiment, a printer group configuration is dynamically configured from the host PC 6 side. Can be changed.
[0069]
FIG. 9 is a block diagram showing an electrical connection of the USB I / F controller 31 used in the printer 2a of the second embodiment.
[0070]
Also in the third embodiment, the flow until the host PC 6 recognizes the initial state of the printer system 1 and the printing operation are the same as those of the printer system 1 of the second embodiment. The USB I / F controller 31 of FIG. 9 includes an internal buffer 44 for changing the group configuration in addition to the configuration of the USB I / F controller 31 of FIG. On the USB system, a new endpoint is defined for receiving data from the host PC 6, and data for the new endpoint is received by the internal buffer 44. The USB address for accepting the request is assumed to be the address assigned as the USB hub that is given first. The protocol processing unit 33 distinguishes between the print data and the newly received data.
[0071]
The printer application of the host PC 6 sends an inquiry request for the current printer group configuration or a new group configuration definition (including deletion and addition) request to the printer 2a via this endpoint. These requests are stored in the internal buffer 44 for reception described above, an interrupt is generated via the processor I / F control unit 38 for the processor 21 on the printer 2a side, and the request contents are interpreted by software on the printer 2a side. And execute the process according to the request.
[0072]
FIG. 10 shows a flowchart of processing executed in this case. That is, as described above, the request from the host PC 6 is stored in the reception internal buffer 44, and when an interrupt is generated (step S1), the processor 21 reads the reception internal buffer 44 (step S2). The command is analyzed (step S3), and the following processing is performed.
[0073]
That is, if it is an inquiry about the current group configuration (N in step S4), a list of printer groups and printer addresses is written in the internal buffer 34 for transmission (step S5), and the contents are received by an IN transfer request from the host PC 6 (Step S6) so that the group application information can be acquired in the printer application on the host PC 6 side.
[0074]
If a new group is to be added (Y in step S4, Y in S7), the new group and printer address are read from the internal buffer 44 (step S8), and the printer group table 42 and USB address printer group conversion table 43 are read. It adds (step S9). If necessary, the status (success or error) is notified to the host PC 6 via the transmission buffer.
[0075]
If the number of groups increases or decreases due to a change in the group configuration, the printer 2a acts as a USB hub to the host PC 6 so that the device can be added or deleted on the USB system. The status is notified (step S10). Thereafter, enumeration is executed from the host PC 6 to the new printer 2 group, and the protocol processing unit 33 automatically responds. Then, the group of the new printer 2 is recognized as a new USB printer from the host PC 6.
[0076]
In the case of an existing group deletion request (Y in step S4, N in S7), the entry of the group is deleted from the printer group table 42 (step S11), and the same processing as in step S10 is performed (step S12). . The changing means is realized by steps S7 to S12. Thereafter, the host PC 6 detects the deletion of the device and invalidates the device (group).
[0077]
【The invention's effect】
According to the first aspect of the present invention, when a printer system is constructed in which the present printer is connected to another printer and a host computer is connected to the printer, the other printer is controlled as a USB printer from the host computer. It can be realized by a simple system configuration and simple control on the host computer side.
[0078]
According to the second aspect of the present invention, in the printer according to the first aspect, the printers can be grouped so that a flexible printer system can be used.
[0079]
According to a third aspect of the present invention, in the printer according to the second aspect, the printer capable of printing among the printers belonging to the specified group can execute printing, thereby enabling a flexible printer system to be used. it can.
[0080]
According to a fourth aspect of the present invention, in the printer according to the third aspect, the user who has requested printing can know from which printer the print output is made.
[0081]
According to the fifth aspect of the present invention, in the printer according to the second or third aspect, the registration of the group configuration can be dynamically reorganized, and a flexible printer system can be used.
[0082]
The invention according to claim 6 has the same effect as the invention according to any one of claims 1 to 5.
[Brief description of the drawings]
FIG. 1 is a communication sequence diagram illustrating processing performed by a USB system.
FIG. 2 is a communication sequence diagram illustrating processing performed by a USB system.
FIG. 3 is a block diagram illustrating an overall configuration of a printer system according to a first embodiment.
FIG. 4 is a block diagram illustrating an overall configuration of a printer of the printer system.
FIG. 5 is a block diagram showing electrical connections of a printer controller.
FIG. 6 is a block diagram illustrating an electrical connection of a USB I / F controller of a printer.
FIG. 7 is a communication sequence diagram between the printer and the host PC.
FIG. 8 is a block diagram illustrating electrical connection of a USB I / F controller of a printer according to a second embodiment.
FIG. 9 is a block diagram illustrating electrical connection of a USB I / F controller of a printer according to a third embodiment.
FIG. 10 is a flowchart of processing performed by a USB I / F controller of a printer.
[Explanation of symbols]
1 Printer system
2,2a printer
5 USB I / F
6 Host computer

Claims (6)

In a printer that has a USB (Universal Serial BUS) interface and can be connected to a host computer,
A first table in which addresses on the USB system and actual addresses are registered in association with other printers connected to the printer;
Accepting means for accepting a print request made by designating an address on the USB system from the host computer to the other printer;
When there is a print request, a printing unit that refers to the first table, converts an address on the USB system into an actual address, and causes the other printer indicated by the address to execute the print request When,
A printer characterized by comprising: Instead of the first table,
A second table in which addresses on the USB system and a plurality of other printers that are connected to the printer and do not have a USB interface are grouped and a printer group that identifies each group is associated and registered. When,
A third table in which each printer group is registered in association with an actual address in the other printer belonging to each group identified by the printer group;
With
When there is a print request from the host computer to the other printer by specifying an address on the USB system, the printing unit refers to the second and third tables, and The printer according to claim 1, wherein the other printer belonging to a group corresponding to an address on a USB system is caused to execute the print request. When there is a print request from the host computer to the other printer by specifying an address on the USB system, the printing unit refers to the second and third tables, and Inquiring whether other printers belonging to the group corresponding to the address on the USB system can execute printing, and causing the other printers capable of printing to execute the print request;
The printer according to claim 2. A notification means for notifying the host computer which printer has actually executed the print request when the print request is executed for the other printer capable of printing;
The printer according to claim 3. Receiving a group configuration change request from the host computer, and changing means for changing the registration contents of the second and third tables according to the request;
The printer according to claim 2 or 3, characterized by the above. In a printer system configured by connecting a plurality of printers connected to each other and a host computer,
At least one of the plurality of printers is the printer according to any one of claims 1 to 5,
A printer system characterized by this.

Images