JPH11282641A - Electronic instrument, its controlling method and multi-function system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply switch between a case for driving a device connected to an IEEE1394 network as an individual device and a case for driving the device as a combined multi-function system. SOLUTION: Whether a printer 103 connected to an IEEE1394 bus is connected to a scanner 102 through an interface 222 or not is decided, and when the printer 103 is connected, the printer 103 carries out a copying function or the like as a composite machine cooperated with the scanner 102. In this case, the printer 103 declares the composite machine to the bus. When the printer 103 is not connected, the printer 103 carries out the function of an individual printer. In this case, the printer 103 declares the individual printer to the bus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to, for example, IEEE 1
The present invention relates to an electronic device such as a multifunction system connected by a 394 I / F and a control method thereof.

[0002]

2. Description of the Related Art The IEEE 1394 I / F has a mechanism for knowing the function of each device connected to a bus, for example, the function of a device such as a printer or a scanner.

There are also devices that can be used as a multifunction system by combining devices having different functions, such as using a scanner and a printer in combination as a copier.

[0004]

SUMMARY OF THE INVENTION However, the IEEE
For multiple devices connected to the E1394 bus,
When they are used as an integrated multi-function system having a composite function, these devices cannot be used properly as a multi-function system or as a single device. That is, there is a case where it is desired to operate each device as, for example, a single scanner or a printer, or a case where these devices are combined to operate as a multifunction system. In the current IEEE 1394 I / F, there is no mechanism for selectively using devices connected to the bus in such a manner.

[0005] The present invention has been made in view of the above conventional example, in which each operates as a single device,
It is an object of the present invention to provide a network device and a control method for a network device that can be configured to have a desired configuration by switching the configuration when a combination is desired to operate as a multifunction system.

[0006]

To achieve the above object, the present invention has the following arrangement. That is, each connected device declares its own function, and is an electronic device connected to an interface that uses the device based on the declaration, and is connected to a predetermined device connected to the interface. A determining means for determining whether or not a predetermined condition is satisfied, and
If it is determined that the condition is satisfied, control the device to cooperate with the device, declare that it cooperates, and if it is determined that the condition is not satisfied, Comprises control means for declaring that the device does not cooperate with the device.

Alternatively, each connected device declares its own function, and based on the declaration, in an electronic device connected to an interface that uses the device, the electronic device is connected to a predetermined device connected to the interface. A determination step of determining whether a predetermined condition is satisfied between the two, and if the determination step determines that the condition is satisfied, declares that the device cooperates with the predetermined device. A declaration step for declaring that the device does not cooperate with the device if it is determined that the condition is not satisfied; and cooperating with the device if it is determined that the condition is satisfied. And a control step of controlling the device to perform the control.

Alternatively, each connected device declares its function, and a computer connected to an interface that uses the device based on the declaration declares a function between the device and a predetermined device connected to the interface. A determining step of determining whether a predetermined condition is satisfied, and, if the determining step determines that the condition is satisfied, declares that the device cooperates with the device, and When it is determined that the condition is not satisfied, a declaration step of declaring that the device does not cooperate with the device, and when it is determined that the condition is satisfied, the device is configured to cooperate with the device. A computer-readable storage medium storing a program for executing a control step of controlling a device.

Alternatively, a multi-function system in which each connected device declares its own function and is connected to an interface such that the device is used based on the declaration, wherein the multi-function system is connected to the interface, A scanner unit that reads an image as image data, a printer unit that is connected to the interface and prints out the image, a connection unit that detachably connects the scanner unit and the printer unit, the scanner unit and the printer unit And whether or not is connected,
If it is determined that the scanner unit is connected, the scanner unit and the printer unit declare that they are a single unit that cooperates, and if it is determined that they are not connected, the scanner unit and the printer unit The printer unit includes a control unit that declares that the printer unit operates as a single unit.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, this embodiment is based on IEEE
Since it relates to a system in which devices are connected by a 1394 interface,
The serial bus will be described in advance.

<Overview of IEEE 1394 Technology> With the advent of home digital VTRs and DVDs, it is necessary to support real-time and high-information-volume data transfer of video data and audio data. In order to transfer such video and audio data in real time, and to transfer it to a personal computer (PC) or other digital devices, an interface capable of high-speed data transfer with the necessary transfer functions is required. The interface developed from such a viewpoint is IEEE 1394-1995 (High Pe
rformance Serial Bus) (hereinafter 1394 serial bus)
It is.

FIG. 23 shows an example of a network system configured using a 1394 serial bus. This system is provided with devices A, B, C, D, E, F, G, and H. A-B, A-C, B-D, D-E, C-F
, CG, and CH are connected by a twisted pair cable of a 1394 serial bus.
The devices A to H are, for example, PC, digital VTR, DV
D, digital camera, hard disk, monitor, etc.

The connection method between the devices is such that the daisy chain method and the node branch method can coexist.
A highly flexible connection is possible. Also, each device has its own unique ID, and by recognizing each other, 1
One network is configured in a range connected by the 394 serial bus. Just by sequentially connecting each digital device with a single 1394 serial bus cable, each device plays a role of relay and constitutes one network as a whole. Also one
Plug & Pla which is also a feature of 394 serial bus
It has a function of automatically recognizing the device and the connection status when the cable is connected to the device with the y function. In addition, in a system such as that shown in FIG. 23, when a device is deleted from the network or newly added, the bus reset is performed automatically, and the network configuration up to that point is reset. Rebuild the network. With this function, the configuration of the network at that time can be constantly set and recognized. The data transfer speed is 100/200 / 400M
bps, the device having the higher transfer rate supports the lower transfer rate and is compatible. As a data transfer mode, asynchronous data such as control signals (Asynchronous data: hereinafter referred to as Async)
Asynchronous transfer mode for transferring data) and I for transferring synchronous data (Isochronous data: Iso data) such as real-time video data and audio data.
There is a sochronous transfer mode. The Async data and Iso data are stored in each cycle (usually 125 μ
In S), following the transfer of the cycle start packet (CSP) indicating the start of the cycle, the transfer of the iso data is prioritized and transferred in a cycle.
Next, FIG. 24 shows the components of the 1394 serial bus. 1394 serial bus as a whole layer
It has a structure.

[0014] As shown in FIG. 24, the most hardware type is a 1394 serial bus cable, and there is a connector port to which a connector of the cable is connected.
There are layers. The hardware part is a substantial part of an interface chip, of which the physical layer performs coding and control related to connectors, and the link layer performs packet transfer and cycle time control.
The transaction layer of the firmware section manages the data to be transferred (transacted),
Issue an instruction such as ad or Write. Serial bus management is based on the connection status of each connected
D manages the network configuration.

The software application
The layer differs depending on the software used, and is a part that defines how data is placed on the interface.
It is specified by a protocol such as the V protocol. The above is the configuration of the 1394 serial bus.

Next, FIG. 25 shows a diagram of the address space in the 1394 serial bus.

Each device (node) connected to the 1394 serial bus always has a 64-bit address unique to each node. By storing this address in the ROM, it is possible to always recognize the node address of oneself and the other party, and perform communication specifying the other party. The addressing of the 1394 serial bus is based on the IEEE 1212 standard, and the address setting is performed in the first 10 bits.
Are used for specifying a bus number, and the next 6 bits are used for specifying a node ID number. The remaining 48 bits become the address width given to the device, and can be used as a unique address space. The last 28 bits store information such as identification of each device and designation of use conditions as an area of unique data. The above is the outline of the technology of the 1394 serial bus.

Next, the technology that can be said to be a feature of the 1394 serial bus will be described in more detail. << Electrical Specifications of 1394 Serial Bus >> FIG.
4 shows a sectional view of a serial bus cable. In the 1394 serial bus, a power supply line is provided in a connection cable in addition to two twisted pair signal lines. As a result, power can be supplied to a device having no power supply, a device whose voltage has dropped due to a failure, and the like.

The voltage of the power supply flowing in the power supply line is 8 to 40.
V and the current are specified as the maximum current DC 1.5A. << DS-Link encoding >> DS-Link of data transfer format adopted in 1394 serial bus
FIG. 11 is a diagram for explaining the encoding method. 139
4 In the serial bus, DS-Link (Data / Strobe Lin
k) An encoding method is adopted. This DS-Link coding method is suitable for high-speed serial data communication.
The configuration requires two signal lines. The main data is sent to one of the twisted pairs, and the strobe signal is sent to the other twisted pair. On the receiving side, the clock can be reproduced by taking the exclusive OR of this communicated data and the strobe. This DS-L
Advantages of using the ink encoding method include higher transfer efficiency compared to other serial data transfer methods, and PLL.
Since the circuit is not required, the circuit size of the controller LSI can be reduced. Further, since there is no need to send information indicating that the apparatus is in an idle state when there is no data to be transferred, the transceiver circuit of each device is set to a sleep state. The power consumption can be reduced. << Bus Reset Sequence >> In the 1394 serial bus, each connected device (node) is given a node ID and recognized as a network configuration. When there is a change in the network configuration, for example, a change occurs due to an increase or decrease in the number of nodes due to insertion / removal of a node or turning on / off of a power supply, etc. The node sends a bus reset signal on the bus to enter a mode to recognize the new network configuration. The method of detecting the change at this time is performed by detecting a change in the bias voltage on the 1394 port board. When a bus reset signal is transmitted from a certain node, the physical layer of each node transmits the bus reset signal to the link layer at the same time as receiving the bus reset signal, and transmits the bus reset signal to another node. After all the nodes finally detect the bus reset signal, the bus reset is activated. The bus reset is also started by the above-described start of the cable insertion / removal, the detection by hardware detection due to a network abnormality or the like, and also by directly issuing an instruction to the physical layer by host control from a protocol. Further, when the bus reset is activated, the data transfer is suspended, the data transfer during this period is waited, and after the end, the data transfer is resumed under a new network configuration. The above is the bus reset sequence. << Node ID Determination Sequence >> After the bus reset, each node starts an operation of giving an ID to each node in order to construct a new network configuration. The general sequence from the bus reset to the determination of the node ID at this time will be described with reference to the flowcharts of FIGS. 19, 20, and 21. The flowchart of FIG. 19 shows a series of bus operations from the occurrence of a bus reset to the determination of the node ID and the start of data transfer.

First, in step S101, the occurrence of a bus reset in the network is constantly monitored, and if a bus reset occurs due to power ON / OFF of a node, the process proceeds to step S102.

In step S102, from the reset state of the network, a parent-child relationship is declared between the directly connected nodes in order to know the connection status of the new network. As step S103,
When the parent-child relationship is determined between all nodes, step S
One route is determined as 104. Until the parent-child relationship is determined between all nodes, the parent-child relationship is declared in step S102, and the route is not determined. After the route is determined in step S104, the operation of setting a node ID for giving an ID to each node is performed in step S105. Node IDs in a given node order
Is repeatedly set until IDs are given to all the nodes.
When the IDs have been set to all the nodes as 6, the new network configuration has been recognized by all the nodes, so that data transfer between the nodes can be performed at step S107, and the data transfer is started. In the state of step S107, a mode for monitoring the occurrence of a bus reset is again entered, and when the bus reset occurs, the setting operations from step S101 to step S106 are repeatedly performed.

The above is the description of the flowchart of FIG. 19. The flowchart from FIG. 19 shows the part from the bus reset to the route determination and the procedure from the route determination to the end of the ID setting in a more detailed flowchart. Are shown in FIGS. 20 and 21, respectively. First, the flowchart of FIG. 20 will be described.

When a bus reset occurs in step S201, the network configuration is reset once. The occurrence of a bus reset is constantly monitored in step S201. Next, as a first step of re-recognizing the network connection status reset in step S202, a flag indicating a leaf (node) is set for each device. Further, step S203
Each device checks how many ports it has are connected to other nodes. In accordance with the result of the number of ports in step S204, the number of undefined (undetermined parent-child) ports is checked in order to start the declaration of the parent-child relationship.

Immediately after the bus reset, the number of ports is equal to the number of undefined ports. However, as the parent-child relationship is determined, the number of undefined ports detected in step S204 changes. First, immediately after a bus reset, only a leaf can declare a parent-child relationship. A leaf can be known by checking the number of ports in step S203. Leaf is Step S2
05, for the node connected to
Declare "I am a child, opponent is a parent" and end the operation. The node which has a plurality of ports in step S203 and is recognized as a branch has the number of undefined ports> 1 in step S204 immediately after the bus reset.
First, a flag of branch is set, and in step S207, the process waits for reception of "parent" in the parent-child relationship declaration from the leaf. Leaf declares parenthood,
In step S207, the branch receiving the information appropriately checks the number of undefined ports in step S204. If the number of undefined ports is 1, the branch connected to the remaining port is checked in step S205. "I am a child"
Can be declared. After the second time, even if the number of undefined ports is confirmed in step S204, for a branch having two or more ports, the process waits again in step S207 to accept a "parent" from a leaf or another branch. Eventually, if any one branch, or exceptionally a leaf (because it did not operate quickly to allow child declaration), becomes zero as a result of the number of undefined ports in step S204, then the entire network The only node for which the declaration of the parent-child relationship has been completed and the number of undefined ports has become zero (determined as all ports) is step S
The flag of the route is set as 208, and step S2
As 09, weaving as a root is performed. Thus, the process from the bus reset shown in FIG. 20 to the declaration of the parent-child relationship between all the nodes in the network is completed.

Next, the flowchart of FIG. 21 will be described. First, in the sequence up to FIG. 20, flag information of each node such as a leaf, a branch, and a route is set. Based on the information, classification is performed in step S301. As an operation of giving an ID to each node,
It is from the leaf that the ID can be set first. The IDs are set in ascending order of leaf → branch → route (node number = 0). In step S302, the number N (N is a natural number) of leaves existing in the network is set. Thereafter, step S30
As 3, each leaf requests the root to give an ID. If there are a plurality of such requests, the route performs arbitration (operation of arbitrating one) in step S304, assigns an ID number to one winning node in step S305, and notifies the losing node of a failure result. Do. In step S306, the leaf whose ID acquisition has failed fails issues an ID request again, and repeats the same operation. Step S3 from the leaf whose ID has been obtained
As 07, the ID information of the node is transferred to all nodes by broadcast. When the broadcasting of the one-node ID information ends, the number of remaining leaves is reduced by one in step S308. Here, in step S309, when the number of remaining leaves is one or more, the operation from the ID request in step S303 is repeated, and finally, when all the leaves broadcast ID information, step S309 sets N = 0. Then, the process proceeds to the branch ID setting. The branch ID setting is performed in the same manner as in the leaf setting. First, as step S310, the number M of branches existing in the network (M is a natural number) is set. Thereafter, in step S311, each branch requests the root to give an ID. On the other hand, the root performs arbitration as step S312, and gives the roots in order from the winning branch to the next younger issue that has been given to the leaf. In step S313, the root notifies the branch that issued the request of ID information or a failure result, and in step S314, the branch whose ID acquisition has failed fails issues an ID request again and repeats the same operation. In step S315, the ID information of the node is broadcast and transferred to all the nodes from the branch where the ID has been obtained. When the broadcast of the one node ID information ends, the number of remaining branches is reduced by one in step S316. Here, step S
If the number of the remaining branches is 1 or more as 317, the operation from the ID request in step S311 is repeated.
The process is performed until all the branches finally broadcast the ID information. When all the branches have acquired the node IDs, M = 0 in step S317, and the branch ID acquisition mode ends.

At this point, since only the root node has not acquired the ID information at the end, step S
318 is set as the own ID number among the unassigned numbers, and the root I
Broadcast D information. Thus, as shown in FIG. 21, the procedure from the determination of the parent-child relationship to the setting of the IDs of all the nodes is completed.

Next, the operation in the actual network shown in FIG. 12 will be described as an example with reference to FIG.

Referring to FIG. 12, (root) node B
Are directly connected to node A and node C,
Further, a node D is directly connected below the node C, and a node E and a node F are directly connected below the node D in a hierarchical structure. The procedure for determining the hierarchical structure, the root node, and the node ID will be described below. After the bus reset, first, in order to recognize the connection status of each node, a parent-child relationship is declared between the directly connected ports of each node. The parent and child can be said to be such that the parent is higher in the hierarchical structure and the child is lower. In FIG. 12, it is the node A that first declared the parent-child relationship after the bus reset. Basically, a node (called a leaf) having a connection to only one port of the node can declare a parent-child relationship. Since the user can first know that only one port is connected, it recognizes that this is the edge of the network, and the parent-child relationship is determined from the node that operates earlier in the network. In this manner, the port on the side that has declared the parent-child relationship (node A between AB) is set as a child, and the port on the other side (node B) is set as a parent. Thus, between node AB, child-parent, node E-
The child-parent is determined between D and the child-parent is determined between the nodes FD.
Further up in the hierarchy, among nodes having a plurality of connection ports (referred to as branches), the parent-child relationship is declared further higher in order from the one that has received the parent-child relationship declaration from another node. In FIG. 12, node D first
After the parent-child relationship between E and DF is determined, the parent-child relationship is declared for node C. As a result, node D-
A child-parent is determined between C. The node C, which has received the declaration of the parent-child relationship from the node D, has declared the parent-child relationship to the node B connected to another port. As a result, a child-parent is determined between the nodes C and B. In this way, a hierarchical structure as shown in FIG. 12 is formed, and the parent node B in all finally connected ports is determined as the root node. There is only one route in one network configuration.

In FIG. 12, node B is determined to be the root node. Node B, which has received a parent-child relationship declaration from node A, makes a parent-child relationship declaration to other nodes at an early timing. If so, the root node may have moved to another node. That is, any node may become a root node depending on the transmission timing, and the root node is not always constant even in the same network configuration.

After the root node has been determined, the process enters a mode for determining each node ID. Here, all nodes notify their determined node IDs to all other nodes (broadcast function).

The self ID information includes its own node number, information on the connected position, the number of ports it has, the number of connected ports, information on the parent-child relationship of each port, and the like. As a procedure for assigning a node ID number, first, it is possible to start from a node (leaf) having a connection to only one port.
1, 2, and so on. The node that has obtained the node ID broadcasts information including the node number to each node. As a result, it is recognized that the ID number is “assigned”. When all the leaves have acquired their own node IDs, the next step is to move to a branch, and the node ID number following the leaf is assigned to each node. Similarly to the leaf, the node ID information is broadcast sequentially from the branch to which the node ID number is assigned, and finally, the root node broadcasts its own ID information. That is, the root is always the largest node I
It owns the D number.

As described above, the assignment of the node IDs of the entire hierarchical structure is completed, the network configuration is reconstructed, and the bus initialization is completed. << Arbitration >> In the 1394 serial bus, arbitration (arbitration) of the right to use the bus is always performed prior to data transfer. Since the 1394 serial bus is a logical bus-type network in which each device connected individually relays the transferred signal to transmit the same signal to all devices in the network, packet collision occurs. Arbitration is necessary to prevent This allows only one node to transfer at a given time. As a diagram for explaining arbitration, FIG. 13A shows a diagram of a bus use request and FIG.

When arbitration starts, one or more nodes issue a bus use right request to the parent node. Nodes C and F in FIG. 13A are nodes that have issued a bus use right request. The parent node (node A in FIG. 13) which has received the request further issues (relays) a bus use request toward the parent node. This request is finally delivered to the arbitration route.

The root node that has received the bus use request determines which node uses the bus. This arbitration work can be performed only by the root node, and the node that has won the arbitration is given permission to use the bus.

FIG. 13B is a diagram in which use permission is given to the node C and use of the node F is rejected. For nodes that lose arbitration, DP (data pref
ix) Send a packet to indicate that it was rejected.

The rejected node's bus use request waits until the next arbitration.

As described above, the node that has won the arbitration and obtained the permission to use the bus can start transferring data thereafter. Here, a series of arbitration flows will be described with reference to a flowchart shown in FIG. In order for a node to be able to start data transfer, the bus must be idle. In order to recognize that the data transfer that has been performed earlier is completed and that the bus is currently idle, a predetermined idle time gap length (eg, sub-action. Each node determines that its own transfer can be started by passing the gap. As step S401, As
It is determined whether or not a predetermined gap length corresponding to the data to be transferred, such as SYNC data and Iso data, is obtained. Unless the predetermined gap length is obtained, the request for the right to use the bus required to start the transfer cannot be made, so the process waits until the predetermined gap length is obtained. If a predetermined gap length is obtained in step S401, it is determined in step S402 whether there is data to be transferred.
A request for the right to use the bus is issued to the route so as to secure the bus for transfer as 3. At this time, the transmission of the signal indicating the request for the right to use the bus is finally delivered to the route while relaying each device in the network, as shown in FIG.

If there is no data to be transferred in step S402, the process stands by. Next, at step S404, when the route receives one or more bus use requests at step S403, the route checks at step S405 the number of nodes that have issued use requests. If the selection value in step S405 is the number of nodes = 1 (the number of nodes that issued the use right request is one), the immediately subsequent bus use permission is given to that node. If the selection value in step S405 is the number of nodes> 1 (the number of nodes that have issued use requests), the root performs arbitration work in step S406 to determine one node to which use permission is given. This arbitration work is fair, and the same node is not granted permission every time, and rights are given equally. As step S407, step S4
At step 06, a selection is made to divide the route into one node whose route has been arbitrated and the use of which has been permitted, and another node which has lost the route. Here, for one node that has been arbitrated and has obtained use permission, or for a node that has obtained use permission without arbitration based on the selection value of step S405 and the number of use request nodes = 1, the root is set to the node at step S408. Send a permission signal to The node that has received the permission signal should transfer the data (packet) immediately after receiving it.
To start the transfer. Further, the nodes that have been defeated in the arbitration in step S406 and have not been permitted to use the bus are given step S406.
At step 409, a DP (data prefix) packet indicating an arbitration failure is sent from the root, and the node that has received the packet returns to step S401 to issue a bus use request for performing transfer again, until the predetermined gap length is obtained. stand by.

The flow of arbitration has been described above with reference to the flowchart of FIG. << Asynchronous transfer >> The asynchronous transfer is an asynchronous transfer. FIG. 14 shows a temporal transition state in the asynchronous transfer. The first sub-action gap in FIG. 14 indicates the idle state of the bus. When the idle time reaches a certain value, the node desiring transfer determines that the bus can be used and executes arbitration for acquiring the bus. When the bus use is granted by arbitration, data transfer is then performed in packet format. After the data transfer, the receiving node determines the reception result a for the transferred data.
After a short gap of ack (acknowledgement return code) ack gap, the transfer is completed by returning a response or sending a response packet. The ack is composed of 4-bit information and a 4-bit checksum, and includes information such as success, busy status, and pending status, and is immediately returned to the source node. Next, FIG.
The following shows an example of a packet format for asynchronous transfer.

The packet has a header part in addition to the data part and the data CRC for error correction, and the header part has the destination node ID, the source node ID, the transfer data length and the like as shown in FIG. Various codes and the like are written and transferred. Asynchronous transfer is one-to-one communication from a self-node to a partner node. The packet transferred from the transfer source node is distributed to each node in the network, but the address other than the address for itself is ignored, so that only one destination node reads the packet.

The above is the description of the asynchronous transfer. << Isochronous (Synchronous) Transfer >> Isochronous transfer is synchronous transfer. This isochronous transfer, which can be said to be the greatest feature of the 1394 serial bus, is
This transfer mode is suitable for transferring data that requires real-time transfer, such as multimedia data such as O video data and audio data. While the asynchronous transfer (asynchronous transfer) is a one-to-one transfer, the isochronous transfer is uniformly transferred from one transfer source node to all other nodes by a broadcast function. FIG. 16 is a diagram showing a temporal transition state in the isochronous transfer. The isochronous transfer is executed at regular intervals on the bus. This time interval is called an isochronous cycle. The isochronous cycle time is 125 μS. A cycle start packet indicates the start time of each cycle, and plays a role of adjusting the time of each node. A node called a cycle master transmits a cycle start packet, and after a transfer in a previous cycle is completed, a predetermined idle period (subaction gap) is passed, and then the start of this cycle is announced. Send a cycle start packet. The time interval at which this cycle start packet is transmitted is 125 μS.

FIG. 16 shows channel A, channel B,
As indicated by the channel C, a plurality of types of packets can be separately transferred by being given channel IDs in one cycle. This allows real-time transfer between a plurality of nodes at the same time, and the receiving node fetches only the data of the channel ID desired by itself. The channel ID does not represent the address of the transmission destination, but merely gives a logical number for the data. Therefore, the transmission of a certain packet is 1
From one source node to all other nodes,
It will be transferred by broadcast.

Prior to the packet transmission in the isochronous transfer, arbitration is performed as in the asynchronous transfer. However, since it is not one-to-one communication as in the asynchronous transfer, there is no ack (reception confirmation reply code) in the isochronous transfer. Further, the iso gap (isochronous gap) shown in FIG.
This indicates an idle period necessary for recognizing that the bus is empty before performing the isochronous transfer. After the predetermined idle period has elapsed, a node that wishes to perform isochronous transfer determines that the bus is free, and can perform arbitration before transfer.

Next, FIG. 17 shows an example of the packet format of the isochronous transfer, which will be described.

Each packet divided into each channel has a header portion in addition to a data portion and data CRC for error correction, and the header portion has a transfer data length and a channel length as shown in FIG. NO and other various codes and a header CRC for error correction are written and transferred.

The above is the description of the isochronous transfer. << Bus Cycle >> In actual transfer on the 1394 serial bus, isochronous transfer and asynchronous transfer can coexist.

FIG. 18 is a diagram showing a temporal transition of the transfer state on the bus in which the isochronous transfer and the asynchronous transfer are mixed at that time. The isochronous transfer is executed prior to the asynchronous transfer. The reason is that, after the cycle start packet, the isochronous transfer can be started with a gap length (isochronous gap) shorter than the gap length (subaction gap) of the idle period required to start the asynchronous transfer. Therefore, the isochronous transfer is executed with priority over the asynchronous transfer. In the general bus cycle shown in FIG.
Packets are transferred from the cycle master to each node. As a result, each node adjusts the time, and after waiting for a predetermined idle period (isochronous gap), the node that should perform isochronous transfer performs arbitration and starts packet transfer. In FIG. 18, the channel e, the channel s, and the channel k are sequentially and isochronously transferred.

After the operations from the arbitration to the packet transfer are repeated for the given channel, after all the isochronous transfers in the cycle #m are completed, the asynchronous transfer can be performed. When the idle time reaches the subaction gap where asynchronous transfer is possible, it is determined that the node that wants to perform asynchronous transfer can shift to execution of arbitration. However, the period during which asynchronous transfer can be performed is the time during which the next cycle start packet should be transferred (cyc
le synch) only when a sub-action gap to activate asynchronous transfer is obtained. In the cycle #m of FIG. 18, isochronous transfer for three channels, and then asynchronous transfer (including a
ck) are transferred by two packets (packet 1 and packet 2). After the asynchronous packet 2, it is time to start the cycle m + 1 (cycle synch), and the transfer in cycle #m ends here. However, if the time to transmit the next cycle start packet (cycle synch) has been reached during asynchronous or synchronous transfer operation, do not forcibly interrupt, wait for the idle period after the transfer is completed, and then Send a cycle start packet for the cycle. That is, when one cycle continues for 125 μS or more, it is assumed that the next cycle is shortened by that much from the reference 125 μS. As described above, the isochronous cycle can be exceeded or shortened on the basis of 125 μS. However, the isochronous transfer is always performed if necessary every cycle to maintain the real-time transfer, and the asynchronous transfer may be transferred to the next and subsequent cycles due to the shortened cycle time. The information including such delay information is managed by the cycle master.

The above is the description of the IEEE 1394 serial bus.

<Network System Using IEEE1394> FIG. 1 shows an example of a network system according to the present embodiment. FIG. 1 is a diagram showing a system in which a personal computer (PC) 101, a scanner 102, a printer 103, a digital camera 104, and a hard disk 105 are connected via an IEEE 1394 I / F. FIG. 2 is a block diagram of the printer 103, and FIG. 3 is a block diagram of the scanner 102.

In FIG. 1, the scanner 102 and the printer 103 have a function of constituting a multifunction system by being mutually connected by a bus 222.

As shown in FIG. 2, the printer 103
IEEE 1394 I / F unit 201 allows IEEE 1394
The entire apparatus is controlled by being connected to a bus and executing a program stored in the ROM 205 by the CPU 204. The RAM 202 stores print data received from the PC 101 or the like, bitmap image data for printing, and the like. The printing unit interface 207
The bit image data developed in the RAM 202 is read out in synchronization with the horizontal and vertical synchronization signals, and the printing unit 208
It has a function to send to. The printing unit 208 prints an image on a sheet according to the video data transmitted through the printing unit I / F unit 207. The operation panel 203 includes various switches and a display panel for operation by an operator.

The system bus connection I / F 221 has a function of connecting to an external device through the bus 222. In the case of the present embodiment, the printer 103 is connected to the scanner 102 via the bus 222 and forms a multifunction system.

As shown in FIG. 3, the scanner 102
The IEEE 1394 I / F unit 301 controls the IEEE 1394
The entire apparatus is controlled by being connected to the bus and executing a program stored in the ROM 304 by the CPU 302. A RAM 303 is a RAM for storing the read image data. The image data read by an image reading unit 306 including a scanning optical system, a CCD, and the like, and converted into a digital signal is transmitted via a reading unit I / F unit 305. And stored in the RAM 303. Also, the system bus connection I
/ F307 has a function of connecting to an external device via the bus 222. In the present embodiment, the scanner 102
Is connected to the printer 103.

<Operation of Scanner and Printer> Next, the operation of the scanner 102 and the printer 103 will be described with reference to FIGS. 1, 2 and 3.

When the scanner 102 and the printer 103 are not connected to each other by the bus 222, they operate as independent devices, that is, a scanner and a printer, and also independently connect to the IEEE 1394 bus. On the other hand, when connected to each other by the bus 222, both devices operate as a single multi-function system (MFS), and are declared to be MFSs combined with the devices connected to the bus. At this time, the connection to the IEEE 1394 bus is performed by, for example, the IEEE 1394 I / F unit 201 of the printer 103 as a representative, and the IEEE 1394 I / F unit 3 on the scanner side is used.
01 is connected to the bus, but only passes the signal and does not perform other operations.

The reason for declaring both devices as a single MFS is as follows.

The MFS has a copy function in addition to a printer function and a scanner function. While the printer and scanner functions can be processed independently by each device,
The copy function requires that the scanner and printer operate in synchronism, and it is generally desirable to process as quickly as possible because the operator comes to the machine and operates it. For this purpose, when used as MFS,
It is necessary to manage the scanner and the printer as one.
In addition, it is desirable that a user of the MFS (hereinafter, referred to as a host) be informed that the MFS is operating not as an individual device but as an MFS, since this is in accordance with the actual situation. For example, when performing copying, the host recognizes that both the scanner and the printer are busy, but since the copying is being performed as MFS, it is more user-friendly to answer busy. Further, in the system according to the present embodiment, during a copy operation, image data read by the scanner 102 is not output to the IEEE 1394 bus, but is output to the bus 222.
Is sent directly to the printer 103 through the
A quick copy operation that is not affected at all by the congestion of the 1394 bus is performed, and the traffic on the IEEE 1394 bus is not increased.

Based on the above idea, first, the printer 1
The operation of 03 will be described with reference to the flowcharts of FIG.

<Operation of Printer> First, the CPU 204 of the printer 103 starts the procedure of FIG. 4 by turning on the power or resetting the switch. In FIG.
It is checked whether the scanner 102 is connected via the bus 222 (step S101). This means that, for example, the printer makes an inquiry about the connection to the scanner via the bus 222, and if a response is returned, it is understood that the connection is established.

If connected, then the IEEE
It is checked whether the 1394 bus has been declared as MFS (step S102). If the MFS has not been declared, the bus is reset for the IEEE 1394 bus, and the MFS is re-declared (step S103).

If the printer is not connected to the scanner, it is checked whether the printer is declared to the IEEE 1394 bus as a printer (step S104).
If not declared as a printer, IEEE1
A bus reset is applied to the 394 bus to re-declare it as a printer (step S105). After being declared as a printer, the printer itself operates as a printer. The operation in this case will be described later with reference to FIG.
(Operation as Copying) Next, a case where the printer and the scanner are connected to each other through the bus 222 and the MFP is declared to operate on the IEEE1394 bus and operates will be described. In this case, C
The PU mainly controls the operation as the MFP. The operation program is stored in the ROM 205 as in the case of operating as a printer.

First, the CPU 204 checks whether data or a command has been input from the host (step S106). If it has been input, it is next checked whether it is data or a command (step S107). If it is data, since a job start command must be input before data is input, it is checked whether a job start flag is set (step S108). this is,
In the MFS, in addition to the above-described print operation, it is necessary to switch between a copy operation and a print operation at a break between JOBs. Therefore, a JOB start command is always added before the JOB data, and a JOB start command is issued. This is because a job end command must be added at the end. Therefore, any data input before the JOB start command is received is invalidated. If the job start command has been input and the job start flag has been set, the input data is stored in the RAM 202 (step S109).

On the other hand, if it is determined in step S107 that a command has been input, it is determined whether the command is a copy command (step S110). If so, the operation proceeds to the same operation as when the copy key is pressed, and it is checked whether the printer or scanner is in use (step S1).
11, S112), if both are not in use, the copying operation starts. That is, a scan start command is sent to the scanner 102 via the bus 222, and the image data read by activating the scanner is input to the printer 103 via the bus 222, temporarily stored in the RAM 202, and then sent to the printing unit 208 for printing ( Step S11
3). During this time, no image data flows on the IEEE 1394 bus, so there is no need to affect the communication of other devices connected to the IEEE 1394, and there is no need to affect the IEEE 1394 bus.
Because it is not affected at all by the crowded condition of the 394 bus,
There is an advantage that a quick copy operation can be performed.

If it is determined in step S110 that the command is not a copy command, it is determined whether the command is a print job end command (step S114). If so, this means that the input of the data of the job has been completed, so the CPU 204 resets the job start flag and starts the printing operation (step S11).
4). That is, the print data stored in the RAM 202 is analyzed and converted into bit image data.
The print data is sent to the print unit 208 via the / F 207 and printed. At this time, if the printer is in use for a copy operation or the like, the printer waits until the use of the printer is completed before starting the print operation.

If it is determined in step S114 that the command is not a print job end command, it is determined whether the command is a scan start command (step S11).
6). If so, a scan start command is sent to the scanner 102 via the bus 222, the scanner is activated, image data read by the scanner is input to the printer 103 via the bus 222, and the image data is sent to the host via the IEEE 1394 bus (step S11
7).

If it is determined in step S116 that the command is not a scan start command, a print job
It is determined whether the command is a start command (FIG. 7, step S1).
18). If so, the job start flag is set (FIG. 7, step S119). If it is not any command checked in the above procedure, it is processed as another command. In the present embodiment, other commands are regarded as status inquiry commands, and a status corresponding to the content of the inquiry is returned to the host (step S7, S
120).

On the other hand, if no data or command has been input from the host in step S106, it is checked whether a key on the operation panel 203 has been pressed (step S121). If there is a key input, it is determined whether the copy key 3022 has been pressed (step S122). If so, the process branches to step S111 to perform the same control as that for the copy command.

If the key input is not the copy key, it is determined whether the stop key 3023 has been pressed (step S).
123). When the stop key is pressed, if the copy operation is being performed, the operation of the scanner and the printer is stopped after the copy operation is completed (step S124).

In step S125, the ONLINE key 30
If it is determined that the button 24 has been pressed, it is determined whether the current state is the online state (step S126), and if so, the ONLINE LED is turned off and the state is shifted to the offline state (step S127). ON if offline
The LINE LED is turned on to shift to the online state (step S128).

If the key is not the ONLINE key, it is determined whether or not the pressed key is the numeric keypad 3027 (step S129). If so, it is determined whether any mode is currently being set (step S13).
0). If the mode is being set, the pressed numeric keypad indicates the selection of the mode, so the mode is set according to the selection (step S131). If the mode is not being set, the pressed value is regarded as the number of copies, and the number is set (step S132).

If a key other than the numeric keypad is pressed, it is determined whether the keypad is online (step S133). If the keypad is online, the input key is discarded. If the keypad is offline, control according to the key input is performed. Is performed (step S133). (Operation as a Printer) If the printer 103 operates as a single printer, step S1 in FIG.
04 or step S105 to step S1 in FIG.
Branch to 51.

Here, it is first checked whether data has been input from the host (step S151). If so, it is checked whether it is data or a command (step S152). If it is data, a JOB start command must be input before data is input.
It is checked whether a JOB start flag indicating that the B start command has been input is set (step S153). This is because, in the IEEE 1394, a printer can be shared and used by a plurality of hosts, as in a network environment. Therefore, in order to distinguish print jobs between hosts, a JOB start command must always be added before print job data. This is for adding a job end command after the job data. Therefore, J
All data input before the input of the OB start command, that is, in the state where the JOB start flag is not pressed due to the setting, is invalidated. If the job start command has been input and the job start flag has been set, the input data is stored in the RAM 202 (step S154).

On the other hand, if a command has been input, it is determined whether or not the command is a print job end command (step S155). Since this command means that the input of the data of the print job has been completed, the CPU 2 resets the job start flag, and
04 enters a print operation. That is, the print data stored in the RAM 202 is analyzed and converted into bit image data, which is converted via the printing unit I / F 207 into the printing unit 208.
To print (step S156). At this time, if the printer is in use for a copy operation or the like, the printer waits until the use of the printer is completed before starting the print operation.

When the input command is a print JO
It is determined whether the command is a B start command (step S15).
7) If so, the job start flag is set (step S158).

If the input command is a copy command or a scan start command, it is ignored (steps S159-Y and S160-Y).

If it is another command, it operates according to the command. In the present embodiment, the other commands are regarded as status inquiry commands, and a status corresponding to the content of the inquiry specified by the command is returned to the host (step S161).

On the other hand, if it is not an input from the host, it is determined whether or not a key input has been made (step S162).
If they are 023, they are ignored (step S163)
-Y, step S164-Y). With respect to the other keys, an operation such as setting of an operation mode is performed according to the content of the pressed key (step S165). However, since this part is not related to the present invention, the description is omitted.

As described above, if the printer 103 is connected to the scanner, it is declared as a multifunction system to each device connected to the IEEE 1394 bus, and if it is not connected to the scanner, it is declared as a single printer. I do. (Operation of Scanner) Finally, the operation of the scanner 102 will be described. 8 and 9 are started when the power of the scanner is turned on or the reset switch is turned on.

In FIG. 8, first, the CP
The U302 checks whether the printer 103 is connected via the bus 222 (step S80).
1). As described as the operation of the printer, the printer makes some inquiry from the printer to the scanner via the bus 222 to confirm the presence or absence of the connection. From the viewpoint of the scanner, if there is a connection inquiry from the printer when the power is turned on, it is understood that the printer is connected via the bus 222. In that case, the scanner 102 replies to the printer 103 that it is connected. Thus, the scanner recognizes that the printer is connected to the printer via the bus 222.

If the connection is established, the subsequent operation basically waits for a command sent from the CPU on the printer side via the bus 222 (FIG. 9, step S802).

A command is waited, and if the transmitted command is a scan start command (step S803)
-Y), the image reading unit is activated, image data is input, and sent to the printer 103 via the bus 222 (step S804). In the case of another command, it operates according to the command (step S805). As other commands, there are a mode setting command and a status inquiry command, but they are not related to the gist of the present invention, and thus description thereof is omitted.

On the other hand, if the printer is not connected to the printer, it is checked whether or not the IEEE 1394 bus is declared as a scanner (step S80).
6). If you have not declared as a scanner,
A bus reset is performed on the EE1394 bus, and the EE1394 bus is re-declared as a scanner (step S807).

After being declared as a scanner, the scanner naturally operates as a scanner after that. That is, first, it is checked whether the copy / start key has been pressed (step S808). If pressed, this is the scanner 102
This means that the original has been placed on the upper platen and a scan input instruction has been given. The scan input operation is performed when the copy / start key is pressed and a scan start command is input from the host. Therefore, when the copy / start key is pressed, it is checked whether a scan start command has been input next (step S80).
9, S810), if input, scans the platen to input an image and sends it to the host (step S811). If a command other than the scan start command is entered,
It operates according to the command (step S81
2).

On the other hand, if a cancel start command is input before the copy / start button (steps S813-Y, S814-Y), it is checked whether the copy / start key has been pressed (step S815).
If it is pressed, the original is similarly scanned to input an image and send it to the host (step S811).

Further, even when the scanner and the printer are connected to each other via the bus 222, if an instruction to use each device is given by a command or a switch, the MFS is transmitted to the IEEE 1394. (That is, they are declared as a printer and a scanner, respectively). In this case, in step S101 in FIG. 4, not only is the scanner connected to the system bus, but if the scanner is connected,
It is also determined that an instruction to use as MFS has been given. This is the same in step S801 in FIG. 8 in the scanner. In this case, a scanner and a printer can be accessed from outside.

If the user wants to operate as an MFS such as a copy operation and perform a copy operation without being affected by the status of the IEEE 1394 bus, an instruction to use the MFS is given by a command or a switch, and then a bus reset is performed. And declare it as MFS.

As a method of such switching, for example, a printer and a scanner may be usually declared, and when the copy key is pressed, the MFS may be declared or a command may be sent from the host.

As described above, the printer and the scanner connected to the IEEE 1394 bus can be used as individual devices, or can be used for copying or the like.
Switching to use as FS or the like can be easily performed. When used as an MFS, the user who uses it can use the scanner without being aware of the connection and synchronization between the scanner and the printer, and does not affect the IEEE1394 bus due to data transfer between the scanner and the printer. .

In the present embodiment, IEEE1394
Is described. However, if the network interface is such that the function of the connected device is registered to the bus manager by declaring the individual device, the interface is not limited to IEEE1394, and other interfaces can be similarly used. It can be switched between MFS and the device here.

Also, the scanner and the printer have been described.
The digital camera 104 and the hard disk 105 as shown in FIG. 1 can be controlled to be declared and function as MFS in the above procedure. For example, you can print images from a digital camera with a printer,
By declaring and operating a function of storing image data of a scanner or a digital camera on a hard disk as an MFS, a large amount of image data can be exchanged without using the IEEE 1394 bus.

[0092]

Another embodiment of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or apparatus, and to provide a computer (or CPU or MPU) of the system or apparatus. Is also achieved by reading and executing the program code stored in the storage medium.

In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

Examples of a storage medium for supplying the program code include a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, and CD.
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) Performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, The case where the CPU of the function expansion board or the function expansion unit performs part or all of the actual processing, and the function of the above-described embodiment is realized by the processing.

In the present embodiment, the printer and the scanner have been described as an example of a separate system. However, in a multifunction printer in which the printer and the scanner are one device, they are recognized as one device when copying. , And at other times, the printer and scanner can be declared as separate devices.

[0098]

As described above, according to the present invention, the configuration can be switched between a case where each operates as a single device and a case where it is desired to operate in combination as a multi-function system, to obtain a desired configuration. When used as a multi-function system, the communication traffic between the devices constituting the multi-function system does not affect the communication traffic connecting the multi-function system and the host device.

[0099]

[Brief description of the drawings]

FIG. 1 is a diagram illustrating devices connected to an IEEE 1394 I / F bus.

FIG. 2 is a block diagram showing the inside of a printer 103.

FIG. 3 is a block diagram of a scanner 102.

FIG. 4 is a flowchart of the printer.

FIG. 5 is a flowchart of the printer.

FIG. 6 is a flowchart of the printer.

FIG. 7 is a flowchart of a scanner.

FIG. 8 is a flowchart of the printer.

FIG. 9 is a flowchart of the scanner.

FIG. 10 is a diagram of an operation panel.

FIG. 11 is a diagram for explaining a DS-Link coding scheme.

FIG. 12 is a diagram illustrating a topology setting for determining an ID of each node on a 1394 serial bus.

FIG. 13 is a diagram for explaining arbitration on a 1394 serial bus.

FIG. 14 is a basic configuration diagram illustrating temporal state transition of asynchronous transfer.

FIG. 15 is a diagram illustrating an example of a format of an asynchronous transfer packet.

FIG. 16 is a basic configuration diagram illustrating a temporal state transition of isochronous transfer.

FIG. 17 is a diagram showing an example of a format of a packet for isochronous transfer.

FIG. 18 is a diagram of an example of a bus cycle showing a state of a packet transferred on an actual bus on the 11394 serial bus.

FIG. 19 is a flowchart showing a flow from a bus reset to a determination of a node ID.

FIG. 20 is a flowchart illustrating a flow of determining a parent-child relationship in a bus reset.

FIG. 21 is a diagram showing a state after a parent-child relationship is determined in a bus reset
It is a flowchart figure which shows the flow until a node ID is determined.

FIG. 22 is a flowchart for explaining arbitration.

FIG. 23 is a diagram illustrating an example of a network configuration connected using a 1394 serial bus.

FIG. 24 is a diagram illustrating components of a 1394 serial bus.

FIG. 25 is a diagram showing an address map of a 1394 serial bus.

FIG. 26 is a sectional view of a 1394 serial bus cable.

Claims (30)

[Claims] An electronic device connected to an interface such that each connected device declares its own function and uses the device based on the declaration, and a predetermined device connected to the interface. Determining means for determining whether or not a predetermined condition is satisfied, and controlling the device so as to cooperate with the device when the determining means determines that the condition is satisfied. An electronic apparatus, further comprising: control means for declaring that the device cooperates and, when it is determined that the condition is not satisfied, declaring that the device does not cooperate with the device. 2. The electronic apparatus according to claim 1, wherein the condition includes that the device is connected to the device by a predetermined connection unit. 3. The electronic apparatus according to claim 2, wherein the condition further includes a designation that cooperates with the device. 4. The electronic apparatus according to claim 3, wherein the designation of cooperating with the device is given via the interface. 5. The electronic apparatus according to claim 2, further comprising a designation unit for designating cooperation with the device. 6. The electronic apparatus according to claim 1, wherein the connection unit exchanges data with the device using a communication path different from the interface. 7. The predetermined device is a scanner that reads an image as image data, and the control unit makes a declaration to cooperate with the scanner when the condition is satisfied. The electronic device according to claim 1, wherein the electronic device is controlled to output the read data by the connection unit. 8. The predetermined device is a printer that prints out an image, and when the condition is satisfied, the control unit issues a declaration to cooperate with the printer and reads image data. 2. The electronic apparatus according to claim 1, wherein the connection unit controls transmission to the printer. 9. The interface is an IEEE 139
2. The electronic device according to claim 1, wherein the electronic device is a serial bus conforming to four standards. 10. An electronic device connected to an interface that uses each of the connected devices to declare its own function based on the declaration, and a predetermined device connected to the interface. A determination step of determining whether a predetermined condition is satisfied between the above, and, in the determination step, when it is determined that the condition is satisfied, declare that the device cooperates with the predetermined device. A declaration step of declaring that the device does not cooperate with the device if it is determined that the condition is not satisfied; and cooperating with the device if it is determined that the condition is satisfied. A control step of controlling the device to perform the control. 11. The method according to claim 10, wherein the condition includes that the device is connected to the device by a predetermined connection unit. 12. The control method for an electronic device according to claim 11, wherein the condition further includes an instruction to cooperate with the device. 13. The method according to claim 10, wherein the connection unit exchanges data with the device using a communication path different from the interface. 14. The device according to claim 1, wherein the predetermined device is a scanner that reads an image as image data, and the control step causes the connection unit to output the data read by the scanner when the condition is satisfied. The control method of an electronic device according to claim 10, wherein the control is performed. 15. The method according to claim 15, wherein the predetermined device is a printer that prints out an image, and the control step reads the image data and transmits the image data to the printer by the connection unit when the condition is satisfied. The control method of an electronic device according to claim 10, wherein the control is performed. 16. The interface is an IEEE 13
The method according to claim 10, wherein the serial bus is a serial bus conforming to the 94 standard. 17. A computer connected to an interface that uses each of the connected devices to declare its own function based on the declaration and communicates with a predetermined device connected to the interface. In a determination step of determining whether a predetermined condition is satisfied, and by the determination step, if it is determined that the condition is satisfied, declare that cooperates with the device,
A declaring step of declaring that the device does not cooperate if it is determined that the condition is not satisfied, and cooperating with the device if it is determined that the condition is satisfied A computer-readable storage medium storing a program for executing a control step of controlling the device. 18. The storage medium according to claim 17, wherein the condition includes that the device is connected to the device by a predetermined connection unit. 19. The storage medium according to claim 18, wherein the condition further includes a designation that cooperates with the device. 20. The storage medium according to claim 17, wherein said connection means exchanges data with said device using a communication path different from said interface. 21. The device, wherein the device is a scanner for reading an image as image data, and the control step controls, when the condition is satisfied, to output the data read by the scanner by the connection means. 18. The storage medium according to claim 17, wherein: 22. The device, wherein the device is a printer that prints out an image, and the control step controls, when the condition is satisfied, reading image data and transmitting the image data to the printer by the connection unit. 18. The storage medium according to claim 17, wherein: 23. The interface is an IEEE 13
18. The storage medium according to claim 17, wherein the storage medium is a serial bus conforming to the 94 standard. 24. The electronic device according to claim 7, further comprising a printing unit that prints out an image. 25. The electronic apparatus according to claim 8, further comprising reading means for reading an image as image data. 26. A multi-function system in which each connected device declares its own function and is connected to an interface such that the device is used based on the declaration, wherein the multi-function system is connected to the interface. A scanner unit that reads an image as image data, a printer unit that is connected to the interface and prints out the image, a connection unit that detachably connects the scanner unit and the printer unit, the scanner unit and the printer unit It is determined whether or not is connected, and if it is determined that it is connected,
The scanner unit and the printer unit declare that they are a single unit that cooperates with each other, and if it is determined that they are not connected, the scanner unit and the printer unit each operate as a single unit. A multi-function system comprising: a control unit for declaring. 27. The controller further determines whether or not the scanner and the printer are specified to cooperate, in addition to whether or not the scanner and the printer are connected. 27. The multi-function system according to claim 26, wherein: 28. The multifunction system according to claim 26, wherein the designation that the scanner and the printer cooperate is given via the interface. 29. The multifunction system according to claim 26, further comprising designating means for designating that the scanner and the printer cooperate. 30. The interface is an IEEE 13
The multi-function system according to claim 26, wherein the multi-function system is a serial bus conforming to the 94 standard.