JPH07325513A - Communication management apparatus of image forming network - Google Patents

Abstract

PURPOSE:To realize efficient communication management of an image forming network. CONSTITUTION:This communication management apparatus is a communication management apparatus of the image forming network having plural copying machines 2, a host computer 1 and public wirings 3 for connecting these copying machines 2 to a host computer 1. Time slots allotted to one or each of the plural copying machines 2 are prepd. as the time zones for making access to the host computer 1. The time slots are set in duration in accordance with the max. errors predicted in the internal clocks of the allotted copying machines 2, the max. connecting time predicted to be required for circuit connection, the max. communication time predicted to be required for communication and the number of units of the allotted copying machines. The copying machines 2 execute the access to the host computer 1 within the allotted time slots.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication management device for an image forming network, and more particularly to an image forming network provided with a plurality of image forming devices, a managing device, and a communication line connecting the image forming device and the managing device. Communication management device.

[0002]

2. Description of the Related Art An image forming network system for managing a plurality of copying machines (an example of an image forming apparatus) using a public line is used for collectively managing operation data of the copying machines. There, the operation data of each copying machine is transmitted to the host computer of the center via a public line and managed by the host computer. There are two types of transmission methods: a center calling method that calls each copying machine from the center host computer side and a terminal calling method that calls the host computer from each copying machine side.

In the case of the center calling system, it is possible for the host computer side to sequentially call each copying machine to efficiently collect data. However, in this case, there is a problem that it is necessary to equip each copying machine with a dedicated line. That is, there is a problem that the line cannot be used together with the other communication device (for example, facsimile) and the copying machine.

In the case of the terminal call system, even if a dedicated line is not provided for the copying machine (for example, even if a line is used together with a communication device such as a facsimile machine), the connection between the host computer and the copying machine is not required. It is possible to communicate with. However, there is a problem that the line cannot be interrupted while another copier or another terminal is communicating with the host computer.

Therefore, in the case of the terminal calling method, the transmission time is assigned to each copying machine side in advance so that the communication time with the host computer does not overlap between the copying machines. In the terminal calling method, it is common to send the operating data of each copying machine to the host computer at regular intervals during a limited time period at night when it is not necessary to handle the abnormalities that occur when the copying machine is operating. is there. In order to efficiently manage the operation data of a large number of image forming apparatuses within this limited time zone, the processing time of the host computer is divided into time slots, and each copying machine is assigned to this time slot. There is.

Each copier preferably communicates with the host computer within its assigned time slot. However, in actuality, there is an error in the internal clock of each image forming apparatus, and since the connection time required for line connection is not constant, communication may not end within the set time slot. Further, interrupt communication by another communication device may make communication in the allocated time slot impossible.

When communication is impossible, the copying machine redials, so that the transmission time may go into the next time slot assigned to another copying machine. In this case, even if the copying machine assigned to the next time slot calls the host computer, the host computer is communicating with the preceding copying machine, and communication cannot be performed. The phenomenon that the communication by the copying machine assigned to the time slot later in time is obstructed by the delay in the communication of the preceding copying machine spreads to the succeeding copying machines one after another, and the terminal line is extended for a long time by each copying machine. Will result in being occupied.

Moreover, the shorter the redial interval, the higher the possibility of line connection, but according to the JATE standard, only redials up to 3 times within 3 minutes are permitted. Therefore, if another copying machine accesses the host computer during the period in which redialing is impossible, the copying machine will repeat redialing for a long time.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to realize efficient communication management in an image forming network. Another object of the present invention is to eliminate the need for a dedicated line and reduce the initial cost.

[0010]

A communication management apparatus according to the present invention includes a plurality of image forming apparatuses, a management apparatus and a communication line for connecting the image forming apparatus and the management apparatus to each other. It is a device. This communication management device comprises slot allocation means and access means.

The slot allocation means predicts the maximum error in the internal clock of the allocated image forming apparatus, the maximum connection time expected to be required for line connection, the maximum communication time expected to be required for communication, and the image to be allocated. One time slot whose length is set based on the number of forming devices
Alternatively, it is assigned to each of a plurality of image forming apparatuses as a time zone in which the management apparatus is accessed. The access means causes the image forming apparatus to access the management apparatus within the time slot assigned by the slot assigning means.

Here, there is further provided redial time management means for managing the next access time when the image forming apparatus detects that the management apparatus is busy during access to the management apparatus.
The access unit may be configured to re-execute the access from the image forming apparatus to the management apparatus based on the next access time. Further, when the slot allocation means further prepares a spare slot to which the image forming apparatus is not allocated and the image forming apparatus cannot access in the allocated time slot, the image forming apparatus transfers from the image forming apparatus to the management apparatus in the spare slot. Can also be configured to perform the access of.

The communication management apparatus according to the present invention comprises a slot allocation means, a redial time management means, and an access means. Here, the slot allocation means is
A time slot in which the time slot for accessing the management apparatus is assigned to the image forming apparatus, and a spare slot which is not assigned are prepared. The redial time management means manages the next access time when the image forming apparatus accesses the management apparatus and detects that the management apparatus is busy, within the allocated time slot and the spare slot prepared after this time slot. To do. The access means causes the image forming apparatus to access the management apparatus within the time slot assigned by the slot assignment means, and when it is detected that the management apparatus is busy, the image forming apparatus is accessed based on the next access time. To access the management device.

[0014]

According to the present invention, the slot allocation means allocates a time slot as a time zone in which the management device is accessed for each one or a plurality of image forming devices. This time slot is the maximum error expected in the internal clock of the assigned image forming apparatus, the maximum connection time expected to be required for line connection, the maximum communication time expected to be required for communication, and the assigned image forming apparatus. The length is set based on the number of units. The access unit causes the image forming apparatus to access the management apparatus within a time slot assigned to each image forming apparatus. As a result, each image forming apparatus will access the management apparatus within the assigned time slot. The time slot is the maximum error of the internal clock,
The length is set based on the maximum connection time required for line connection, the maximum communication time, and the number of image forming apparatuses to be allocated, which enables efficient communication management.
It is possible to satisfy the specified condition of the number of redials such as ATE.

When the image forming apparatus is configured so that the redial time managing means manages the next access time when it detects that the managing apparatus is busy during the access to the managing apparatus, a plurality of image forming apparatuses are provided in the time slot. It is possible to efficiently perform communication management even when is assigned. When a spare slot that is not assigned to image formation by the slot assigning means is further prepared,
If the image forming apparatus cannot be accessed within the assigned time slot, the spare slot can be used to communicate with the management apparatus. There is no obstruction, and the monopolization of the terminal line by each image forming apparatus is reduced.

The slot allocation means prepares a time slot allocated to each image forming apparatus and a spare slot which is not allocated to the management apparatus, and the redial time management means causes the image forming apparatus to manage the management apparatus. When the next access time when the communication is detected is managed in the allocated time slot and the spare slot prepared after this time slot, the image forming apparatus is allocated in the allocated time slot. Even if the management device cannot be accessed in step 2, the spare slot can be used to communicate with the management device, and the exclusive use of the terminal line is reduced without hindering access to other image forming devices.

[0017]

1 shows an image forming network to which an embodiment of the present invention is applied, a host computer 1 and a plurality of copying machines 2 are connected in a network form via a public line 3. The host computer 1 inputs / outputs operation data of each copying machine 2 via the public line 3. The host computer 1 has a central processing unit (CPU) 4 as shown in FIG. A RAM 5 for temporarily storing various data and a ROM 6 for storing a processing program and various parameters are connected to the CPU 4. Further, an input / output unit 7 for inputting / outputting data is connected to the CPU 4. In addition, the CPU4
A CRT 8 for display, a keyboard 9 for input, an external storage device 10, etc. are connected. Input / output unit 7 is RS232C
Etc., and is connected to the public line 3 (FIG. 1) via a modem (not shown).

In the RAM 5 of the host computer 1,
A time slot table in which the host computer 1 and each copying machine 2 regularly communicate with each other is stored as a time slot table. This time slot table is constructed, for example, as shown in FIG. In this example, the first to the first time periods when each copying machine 2 accesses the host computer 1 in the evening time period during which regular communication is performed.
The sixth time slot is assigned, and the spare slot is assigned after the sixth time slot.

Two copying machines 2 are assigned to each of the first to sixth time slots. The first to sixth time slots are (maximum error expected in internal clock of copying machine 2) + (maximum connection time expected to be required for line connection + maximum communication time expected to be required for communication) * It is set to the length of (number of allocated copiers 2) + (maximum connection time expected to be required for line connection). Here, it is assumed that the error of the internal clock of each copying machine 2 is less than 15 seconds, the line connection time when each copying machine 2 communicates with the host computer 1 is less than 10 seconds, and the line occupation time during communication is 20 seconds. Thus, the length of each time slot is set to 85 seconds.

When the copying machine 2 assigned to the sixth slot has the largest internal clock error and the host computer 1 is successfully accessed at the time of the third dialing, the time at which the communication ends is the start time of the spare slot. 20 seconds later. In order for the copying machine 2 which cannot be accessed within the allocated time slot to reliably access the host computer 1 within this spare slot, it is necessary to dial 20 seconds after the spare slot start time. is there. Considering the maximum error expected in the internal clock of the copying machine 2 that could not be accessed within the allocated time slot, the length of the spare slot is (time from the start time of the spare slot to the start of access). Interval) + (maximum error expected in internal clock of copy machine 2) + (maximum connection time expected to be connected to the line) + (maximum communication time expected to be required for communication), and set to 65 seconds can do.

The processing program stored in the ROM 6 of the host computer 1 includes processing for collecting operation data of the copying machine 2 as shown in FIG. Here, first, in the evening time zone in which regular communication is performed, the processing time of the host computer 1 is divided into predetermined times to set time slots (step S1).
Next, the copying machine 2 for executing the access is assigned to each time slot, and at the same time, when the copying machine 2 cannot access the allocated time slot, the time slot for executing the access is assigned to the copying machine 2. It is set as an empty spare slot (step S2). further,
The time slots of the time slots and the spare slots assigned to each copying machine 2 are transmitted to each copying machine 2 via the public line 3 (step S3).

The redial interval when a line busy is detected when accessing the host computer 1 is set as shown in FIG. 6 according to the time slot assigned to the copying machine and the number of dials. When each copying machine 2 detects the line busy of the host computer 1 at the first and second dials, the next redial is possible within the same time slot. Therefore, it is considered that the line busy is caused by the copying machine 2 assigned to the same time slot, and the redial is set after 20 seconds when this communication is predicted to end. If line busy is detected during the third access, the next redial must be performed beyond the assigned time slot. At this time, the redial is set to be executed within the closest spare slot. Therefore, when the copying machine 2 assigned to the first slot cannot access the host computer 1 by dialing three times,
Redialing is executed in the spare slot prepared 510 seconds after the time slot start time.
However, since the maximum access time by the copying machine 2 assigned to the sixth slot is offset by 20 seconds in the spare slot, 53 seconds from the time slot start time in consideration of this.
It is set to redial after 0 seconds. Similarly, when the copying machine assigned to the second slot cannot access the host computer 1 by dialing three times, it is set to redial after 445 seconds from the slot start time. Similarly, if the copying machines assigned to the third slot, the fourth slot, and the fifth slot cannot access the host computer 1 by dialing three times, after 360 seconds,
It is set to perform redialing after 270 seconds and 190 seconds. If the copying machine 2 assigned to the sixth slot cannot access the host computer 1 by dialing three times, redialing is performed in the spare slot prepared immediately after the sixth slot. , JA
It becomes impossible to meet the TE standard. Therefore,
Further, it is set to redial in the next spare slot. That is, the copying machine assigned to the sixth slot is dialed three times and the host computer 1
If the access to the access point is not possible, the redial is set 680 seconds after the time slot start time.

Further, when the host computer 1 cannot be accessed by redialing in the spare slot, redialing is performed in the next spare slot prepared after 575 seconds. Therefore, when the copying machine 2 assigned to each slot cannot access the host computer 1 by dialing four times or more, the redialing is performed 575 seconds after the last dialing. Thereafter, the access from the copying machine 2 is accepted during the relevant time zone (step S4).

As shown in FIG. 3, the copying machine 2 is provided with a control unit 11. The control unit 11 includes a CPU and RA
It is composed of a microcomputer system including M, ROM, various drivers, and various IOs. The control unit 11 includes an input key unit 12 provided on the operation panel of the copying machine 2.
And the display unit 13 is connected. Further, the storage unit 14 of the control unit 11 stores a time slot number assigned by the host computer 1, a time interval for redialing, and the like. Further, the control unit 11 is provided with RS232.
An input / output unit 115 including an interface such as C is connected. The input / output unit 15 is connected to the public line 3 (FIG. 1) via a modem (not shown).

The processing program stored in the control section 11 of the copying machine 2 includes the processing shown in FIG. 7 for collecting the operation data of the copying machine 2. Step S12
At, it is determined whether or not the time of the internal clock of the copying machine 2 has reached the allocated time slot start time. If it is determined that the time slot start time has come, step S
Move to 13. In step S13, the redial counter in the RAM is reset. Further, step S14
At, the copying machine 2 gives a command to the connected modem to dial the host computer 1.

In step S15, it is determined whether the connection to the host computer 1 is possible. Host computer 1
Then, the copying machine 2 transmits the operation data stored in the storage unit 14 to the host computer 1 (step S16). When the line busy is detected and the host computer 1 cannot be connected in step S15, the process proceeds to step S17 and "1" is added to the redial counter. In step S18, the storage unit 1
The time interval for redialing stored in 4 is read according to the value of the redial counter. In step S19, it is determined whether or not the current time is the time for redialing based on the redialing time interval read out in step S18. When it is time to redial, the process proceeds to step S14, and the host computer 1
Dial again.

Next, a specific example of the operation of the above embodiment will be described. The pair of copying machines 2 assigned to one time slot access the host computer 1 when the assigned time of the set time slot is reached (step S14). When there is no error in the internal clocks of the two copying machines 2, the host computer 1 is accessed at the same time. When one copying machine 2 is connected to the host computer 1, the other copying machine 2 detects line busy and redials after 20 seconds, which is the line occupation time during communication of one copying machine 2 (step S14). Therefore, assuming that there is no error in the internal clocks of both copying machines 2 and the line connection time is 10 seconds, the predetermined communication ends 30 seconds after one copying machine 2 accesses the host computer 1, and then the other communication is completed. If the copying machine 2 is connected to the host computer 1 and the communication is completed within 20 seconds, it takes 60 seconds until both copying machines 2 assigned to one slot complete the predetermined communication.

Assuming that the error of the internal clock of the copying machine 2 is 15 seconds, one copying machine 2 will have one copying machine 2 15 seconds after the start time of the assigned time slot.
Access is started (step S14). At this time,
If the line connection time is 10 seconds and the communication time is 20 seconds, it will take 45 seconds until one of the copying machines 2 finishes the communication. In the meantime, the other copying machine 2 detects the line busy by the first dial and redials after 30 seconds (step S14). If the line connection time of the other copying machine 2 is 10 seconds and the communication time is 20 seconds, it takes 75 seconds for the two copying machines to finish predetermined communication. Therefore, if the host computer 1 does not have interrupt communication, it takes at least 60 seconds and at most 75 seconds for the copying machine 2 assigned to one time slot to perform predetermined regular communication. Becomes Since one time slot is set to 85 seconds, for example,
If the host computer 1 does not have interrupt communication,
The copying machine 2 assigned to each time slot can complete communication with the host computer 1 within the time slot.

When the copying machine 2 dials the host computer 1 in one time slot and the line busy is detected by interrupt communication or the like, the two copying machines 2 decide to redial after 30 seconds. (Step S14). If one of the copying machines 2 can access the host computer 1, the one copying machine 2 completes the communication after 20 seconds (step S16).
The other copying machine 2 also detects the line busy during the second dialing, and therefore redials after 20 seconds (step S14). At this time, since the communication of one of the copying machines 2 has been completed, it is possible to change from the first dialing time to 9 seconds.
Communication will be completed after 0 seconds. This is when there is no error in the internal clock of each copying machine 2 and the line connection time is considered to be 10 seconds. Assuming that the internal clock of each copying machine 2 has an error of 15 seconds, each copying machine 2 that detects busy due to interrupt communication at the first dialing performs redialing 45 seconds after the start time of the assigned time slot ( Step S14). At this time, one copy machine 2
If the host computer 1 can access the host computer 1, the copying machine 2 completes the communication 75 seconds after the start time of the time slot. The other copier 2
Indicates that the line busy by one of the copying machines 2 is detected at the time of the second dial and the time of the third dial is 75 seconds after the start time of the time slot. It is assumed here that the maximum connection time required for line connection is 10 seconds, so 3
The time when the line is connected to the host computer 1 by the second dial is within 85 seconds from the time slot start time, and the line connection is made before the copying machine 2 assigned to the next time slot accesses the host computer 1. Is possible.

In this case, the copying machine 2 assigned to one time slot needs 10 times to complete the regular communication.
It will take 5 seconds and will dig into the next time slot for 20 seconds. Therefore, when the copying machine 2 assigned to the next time slot dials the host computer 1 (step S14), the line busy is detected at the first dialing. The copying machine 2 assigned to this time slot redials 30 seconds after the busy detection (step S14), and one of them is connected to the host computer 1. Therefore, also in this case,
The time required for one copying machine 2 to complete the communication is 75 seconds after the start time of the time slot. The time required for the other copying machine 2 to complete the communication is 105 seconds after the start time of the time slot.

In this way, the copying machine 2 assigned to each time slot completes the access to the host computer 1 by a maximum of 20 seconds, which is 6 seconds.
This offset time is absorbed by the spare slot prepared next to the first time slot. Therefore, if there is interrupt communication with the host computer 1, each copying machine 2 can reliably access the host computer 1 by dialing within 3 times if the interrupt communication is within 20 seconds. Will also be satisfied.

When the interrupt communication to the host computer 1 is for 20 seconds or more, the copying machine 2 assigned to one time slot has 3 times in that time slot.
The host computer 1 may not be accessible even after dialing twice. In such a case, the copying machine 2 that was unable to access the host computer 1 is set to automatically perform communication in the spare slot time zone.

When the time slot as shown in FIG. 4 is set, when the copying machine 2 assigned to the first slot cannot access the host computer 1 by dialing three times, the first time slot starts. 51 from time
The host computer 1 is accessed using the time slot of the spare slot existing after 0 second. At this time, 5 seconds from the start time of the first time slot in consideration of the shift time of 20 seconds by the copying machine 2 assigned to the sixth time slot.
It is set to redial after 30 seconds. Similarly, when the copying machine 2 assigned to the second time slot, the third time slot, the fourth time slot, and the fifth time slot is unable to access the host computer 1 by dialing three times, each is 445. Seconds later,
Redialing will be performed after 360 seconds, 275 seconds, and 190 seconds.

When the copying machine 2 assigned to the sixth time slot cannot access the host computer 1 by dialing three times, if dialing is performed in the time slot of the next spare slot, it will take 3 minutes within 3 minutes. Dialing will be performed more than once, which does not meet the JATE standard.
Therefore, in this case, redialing is performed using the time of the next spare slot. At this time, the copying machine 2 assigned to the sixth time slot dials the fourth time after 680 seconds.

In this embodiment, the dial tone detection time and the dial time at the time of communication are fixed values and are ignored. Further, although it takes a certain time to detect the line busy, the redial interval is set to 30 seconds, and the line busy detection time is shorter than the redial time, so it can be ignored. In this embodiment, the length of the time slot to which the two copying machines 2 are allocated is (the maximum error predicted by the internal clock of the copying machine 2) +
(Maximum connection time expected to be required for line connection + maximum communication time expected to be required for communication) * (number of allocated copying machines 2) + (maximum connection time required for line connection) Since the setting is made, the two allocated copying machines 2 can efficiently access the host computer 1 within the time slot. Further, even if the interrupt communication to the host computer 1 occurs within the assigned time slot, each copying machine 2 can access the host computer 1 by dialing within 3 times, and the host computer 1 can be accessed in the shortest time. The communication with the computer 1 can be completed. Furthermore, even if the access cannot be made within the assigned time slot, the spare slot can be used to communicate with the host computer 1 and the host computer 1 of the copying machine 2 assigned to the next time slot can be used. Will not hinder access. Moreover, it is possible to meet the JATE standard without dialing more than three times within 3 minutes.

When a public line is used as the communication line, the initial cost can be reduced as compared with the case where a dedicated line is laid, and a long construction period is not required. Further, by assigning two or more copying machines 2 to one time slot, even if there is an error in the internal clock of each copying machine 2, the blank time for access within the time slot is reduced, It is possible to avoid a decrease in communication efficiency.

[Other Embodiments] (a) In the above embodiments, the dial tone detection time and the dial time during communication are fixed values and are ignored. In consideration of the dial tone detection time and dial time unique to each copying machine 2, it is possible to set the time when dialing to the host computer 1 is advanced by these times for dialing. (B) The time slot configuration of the host computer 1 can be a table as shown in FIG.

Here, three copying machines are respectively assigned to the first to sixth time slots. When the copying machine assigned to each time slot sequentially accesses the host computer 1 and completes the communication, assuming that the line connection time is less than 10 seconds and the maximum communication time required for the communication is 20 seconds, (10 + 20) * 3 = 90 seconds. If the maximum error predicted for the internal clock of the copying machine 2 is 15 seconds, the communication between the three copying machines will be completed in 105 seconds. Finally here is the host computer 1
The copier 2 that communicates with the device dials three times within the assigned time slot. If the host computer 1 cannot be accessed even after dialing three times due to factors such as interrupt communication to the host computer 1, redialing after another 20 seconds will be performed.
It becomes impossible to meet the TE standard. Therefore,
When the host computer 1 cannot be accessed by dialing these three times, the spare computer provided after the sixth slot is set to access the host computer 1. Therefore, the first to sixth time slots are set to 105 seconds, respectively. In this case, since there is no deviation in the communication time by the copying machine 2 assigned to the sixth slot, the spare slot has the maximum error predicted by the internal clock of the copying machine 2 and the maximum connection predicted by the line connection. It can be set to 45 seconds considering only the time and the maximum communication time expected to be required for communication.

When the copying machine 2 assigned to the first to sixth time slots detects a line busy at the time of accessing the host computer 1, the copying machine 2 returns to the host computer 1 again at a redial interval as shown in FIG. It will be accessed. That is, the first and second redial intervals are common to each time slot, and redial is performed 20 seconds after the line busy is detected. Host computer 1 in the spare slot for the third redial
The redial intervals of the copying machines 2 assigned to the first to fifth slots are 630 seconds after the time slot start time and 525 seconds, respectively.
Seconds, 420 seconds, 315 seconds, 210 seconds later. However, if the copying machine assigned to the sixth slot redials in the spare slot prepared immediately after, JAT
It becomes impossible to meet the E standard. Therefore, the host computer 1 is accessed in the next spare slot. Therefore, the time interval in which the copying machine 2 assigned in the sixth slot makes the third redial is 780 seconds after the time slot start time.

When redialing four times or more, each copying machine 2 cannot access the host computer 1 in the spare slot, and the host computer 1 is further accessed in the next spare slot. Access will be made, in this case 6 from the last redial time
Redialing will be done after 75 seconds. (C) The data of the assigned time slot and the spare slot may be directly input from the operation panel of the copying machine 2 or may be stored in the RAM or the ROM in advance.

[0041]

According to the present invention, the length of the time slot to which the image forming apparatus is assigned is such that the maximum error expected in the internal clock of the image forming apparatus, the maximum connection time expected to be required for line connection, and the communication. Since it is set based on the maximum communication time expected to take and the number of assigned image forming devices, the assigned image forming devices can efficiently access the management device within the time slot. Becomes Further, even if the interrupt communication to the management apparatus is input within the assigned time slot, each image forming apparatus can access the management apparatus by dialing within a predetermined number of times, and can communicate with the management apparatus in the shortest time. Communication can be completed. Further, even when the access cannot be made within the assigned time slot, the spare slot can be used to communicate with the management apparatus, and the image forming apparatus assigned to the next time slot can send the image forming apparatus to the image forming apparatus. It will not hinder access. Moreover, since the length of the time slot is set based on the error of the internal clock, the maximum connection time, the maximum communication time, etc.
It can meet the TE standard.

Further, by allocating two or more image forming apparatuses to one time slot, even if there is an error in the internal clock of each image forming apparatus, the blank time for access within the time slot is set. It is possible to avoid a decrease in communication efficiency.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an image forming network in which the present invention is adopted.

FIG. 2 is a control block diagram of a host computer.

FIG. 3 is a control block diagram of the copying machine.

FIG. 4 is an explanatory diagram of a time slot table used in an embodiment of the present invention.

FIG. 5 is a control flowchart of the host computer.

FIG. 6 is an explanatory diagram of a redial interval management table used in an embodiment of the present invention.

FIG. 7 is a control flowchart of the copying machine.

FIG. 8 is an explanatory diagram of a time slot table used in another embodiment.

FIG. 9 is an explanatory diagram of a redial interval management table used in another embodiment.

[Explanation of symbols]

 1 Host computer 2 Copy machine 3 Public line 4 CPU 11 Control unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H04N 1/32 Z (72) Inventor Hiroyuki Inanaka 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Kogyo Co., Ltd. (72) Inventor Katsunori Masai 1-22 Tamatsukuri, Chuo-ku, Osaka Mita Kogyo Co., Ltd.

Claims (4)

[Claims] 1. A plurality of image forming apparatuses, a management apparatus, and a communication line connecting the image forming apparatus and the management apparatus, wherein the maximum error expected in the internal clock of the assigned image forming apparatus, the line. Maximum connection time expected to be connected,
A time slot for accessing the management device for each one or a plurality of image forming devices in a time slot whose length is set based on the maximum communication time expected to be required for communication and the number of allocated image forming devices. A communication management apparatus for an image forming network, comprising: a slot allocation unit that performs allocation as described above; and an access unit that causes the image forming apparatus to access the management apparatus within the time slot allocated by the slot allocation unit. 2. The image forming apparatus further comprises redial time management means for managing the next access time when the management apparatus detects that the management apparatus is busy during access to the management apparatus, the access means accessing the next time. The communication management device of the image forming network according to claim 1, wherein the access from the image forming device to the management device is re-executed based on time. 3. The slot allocating means further prepares a spare slot to which the image forming apparatus is not allocated, and if the image forming apparatus cannot access in the allocated time slot, the spare slot is stored in the spare slot. The communication management apparatus of the image forming network according to claim 1, wherein the image forming apparatus accesses the management apparatus by means of. 4. A plurality of image forming apparatuses, a management apparatus, and a communication line connecting the image forming apparatus and the management apparatus, wherein a time zone for accessing the management apparatus is assigned to each of the image forming apparatuses. Slot allocating means for preparing a reserved time slot and a spare slot that has not been allocated, and the allocation of the next access time when the image forming apparatus detects that the management apparatus is busy during access to the management apparatus. A redial time management unit that manages the reserved slot and a spare slot prepared after this time slot, and access from the image forming apparatus to the management apparatus within the time slot allocated by the slot allocation unit. And when it is detected that the management device is busy, based on the next access time. And access means for the serial image forming apparatus to execute the access to the management device, the communication management apparatus for an image forming network with.