JP3322756B2 - Communication management device for image forming network - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication management apparatus for an image forming network, and more particularly to an image forming network having a plurality of image forming apparatuses, a managing apparatus, and a communication line connecting the image forming apparatus and the managing apparatus. A 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. Here, 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 for calling each copying machine from the host computer of the center and a terminal calling method for calling the host computer from each copying machine.

In the case of the center calling system, the host computer can sequentially call each copying machine to collect data efficiently. However, in this case, there is a problem that each copier needs to have a dedicated line. That is, there is a problem that a line cannot be used in combination with another communication device (for example, a facsimile) and a copying machine.

In the case of a terminal calling system, even if a dedicated line is not provided for a copying machine (for example, when a communication device such as a facsimile machine is used in combination with a line), the communication between the host computer and the copying machine can be performed. It is possible to carry out communication. However, there is a problem that the line cannot be interrupted while another copier or another terminal is communicating with the host computer.

For this reason, in the case of the terminal calling system, a transmission time is allocated in advance to each copying machine 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 periodically transmit the operation data of each copying machine to the host computer during a limited time period during the night when it is not necessary to process abnormalities that occur when the copying machine operates. 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. I have.

Preferably, each copier communicates with the host computer within the assigned time slot. However, actually, there is an error in the internal clock of each image forming apparatus, and the connection time required for the line connection is not constant, so that the communication may not be completed within the set time slot. Further, there are cases where communication within the assigned time slot becomes impossible due to interrupt communication by another communication device.

[0007] When communication is not possible, the copying machine redials, so that the transmission time may enter the next time slot allocated 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 in communication with the preceding copying machine, so that communication becomes impossible. The phenomenon that the communication by the copying machine assigned to the later time slot is hindered by the communication delay of the preceding copying machine spreads to the following copying machine one after another, and the terminal line is extended by each copying machine for a long time. The result is occupancy.

Further, the shorter the interval between redials, the higher the possibility of line connection. However, according to the JATE standard, only up to three redials per 3 minutes are permitted. Therefore, if another copier accesses the host computer during the period in which redialing is not possible, the copier 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 is a communication management apparatus for an image forming network comprising a plurality of image forming apparatuses, a management apparatus, and a communication line connecting the image forming apparatuses and the management apparatus. Device. This communication management device includes a slot assignment unit and an access unit.

The slot allocating means includes a maximum error predicted in the internal clock of the allocated image forming apparatus, a maximum connection time predicted to be required for line connection, a maximum communication time predicted to be required for communication, and an image to be allocated. A time slot whose length is set based on the number of forming devices is 1
Alternatively, allocation is performed as a time zone for accessing the management apparatus for each of the plurality of image forming apparatuses. The access means causes the image forming apparatus to access the management apparatus within the time slot assigned by the slot assignment means.

Here, there is further provided a redial time management means for managing a next access time when the image forming apparatus detects a busy state of the management apparatus when accessing the management apparatus,
The access unit may be configured to re-execute access from the image forming apparatus to the management apparatus based on the next access time. Further, the slot allocating means further prepares a spare slot to which the image forming apparatus is not allocated, and when the image forming apparatus cannot be accessed in the allocated time slot, the image forming apparatus transmits the spare slot to the management apparatus in the spare slot. May be configured to execute the access.

Further, the communication management device according to the present invention includes a slot allocating means, a redial time managing means, and an access means. Here, the slot allocating means is
A time slot in which a time zone for accessing the management apparatus is allocated to the image forming apparatus and a spare slot to which no time slot is allocated are prepared. The redial time management means manages the next access time when the image forming apparatus accesses the management apparatus when it detects that the management apparatus is busy, within the assigned time slot and over the spare slot prepared after this time slot. I do. The access means causes the image forming apparatus to access the management apparatus within the time slot allocated by the slot allocating means. To access the management device from the server.

[0014]

In the present invention, the slot allocating means allocates a time slot as a time zone for accessing the management apparatus for each of one or a plurality of image forming apparatuses. The time slot includes the maximum error estimated in the internal clock of the assigned image forming apparatus, the maximum connection time estimated to be required for line connection, the maximum communication time estimated to be required for communication, and the assigned time of the image forming apparatus. The length is set based on the number. The access means causes the image forming apparatus to access the management apparatus within the assigned time slot of each image forming apparatus. As a result, each image forming apparatus accesses 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, so that efficient communication management can be performed.
It is possible to satisfy the prescribed condition of the number of redials such as ATE.

If the image forming apparatus is configured to manage the next access time when the management apparatus detects that the management apparatus is busy during access to the management apparatus by the redial time management means, a plurality of image forming apparatuses may be stored in a time slot. , The communication management can be performed efficiently. When a spare slot to which no image formation is allocated is further prepared by the slot allocating means,
If the image forming apparatus cannot access within the allocated time slot, it is possible to communicate with the management apparatus using this spare slot. Without blocking, the occupation of the terminal line by each image forming apparatus is reduced.

The slot allocating means prepares a time slot in which a time zone for accessing the management apparatus is allocated to each image forming apparatus and a spare slot not allocated, and the redial time managing means prepares the image forming apparatus by the management apparatus. If the configuration is such that the next access time when communication is detected is managed within the assigned time slot and over the spare slot prepared after this time slot, the image forming apparatus will manage the next access time within the assigned time slot. Therefore, even if access to the management apparatus is not possible, communication with the management apparatus can be performed using the spare slot, and the occupation of the terminal line is reduced without obstructing access to other image forming apparatuses.

[0017]

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

In the RAM 5 of the host computer 1,
A time zone table in which the host computer 1 and each copying machine 2 periodically communicate is stored as a time slot table. This time slot table is configured, for example, as shown in FIG. In this example, in the night time zone in which the regular communication is performed, the first to first time zones in which each copying machine 2 accesses the host computer 1 are set.
A sixth time slot is allocated, and a spare slot is allocated after the sixth time slot.

Two copiers 2 are assigned to the first to sixth time slots, respectively. The first to sixth time slots are (maximum error estimated in the internal clock of the copying machine 2) + (maximum connection time estimated to be required for line connection + maximum communication time estimated to be required for communication) * (The number of copiers 2 to be allocated) + (maximum connection time estimated 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 exclusive time during communication is 20 seconds. The length of each time slot is set to 85 seconds.

When the copying machine 2 assigned to the sixth slot has the largest error in the internal clock and successfully accesses the host computer 1 at the time of the third dialing, the communication ends at the start time of the spare slot. 20 seconds after To ensure that the copier 2 that cannot access within the assigned time slot accesses the host computer 1 within this spare slot, it is necessary to dial 20 seconds after the start of the spare slot. is there. Considering the maximum error expected in the internal clock of the copying machine 2 in which access was not possible within the assigned time slot, the length of the spare slot is expressed as (the time from the start time of the spare slot until the start of access). (Interval) + (maximum error estimated for the internal clock of the copying machine 2) + (maximum connection time estimated to be required for line connection) + (maximum communication time estimated to be required for communication), which is set to 65 seconds can do.

The processing program stored in the ROM 6 of the host computer 1 includes processing as shown in FIG. Here, first, in the nighttime period in which regular communication is performed, the processing time of the host computer 1 is divided into predetermined times, and time slots are set (step S1).
Next, to each time slot, a copier 2 for executing access is allocated. At the same time, when the copier 2 cannot access within the allocated time slot, the time slot for performing access is allocated to the copier 2. It is set as a spare slot that does not exist (step S2). further,
The time slot of the time slot and the spare slot allocated to each copying machine 2 is 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 to which the copying machine is assigned and the number of dials. When each of the copying machines 2 detects the line busy of the host computer 1 by the first and second dials, the next redial is possible within the same time slot. Therefore, it is considered that the cause of the line busy is caused by the copying machine 2 assigned to the same time slot, and the redial is set to be performed 20 seconds after the completion of the communication is expected. If a line busy is detected at the time of the third access, the next redial needs to be performed beyond the assigned time slot. At this time, it is set so that redialing is executed in the spare slot closest to the first. Therefore, if the copying machine 2 assigned to the first slot cannot access the host computer 1 by three dials,
Redial is executed in a 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 shifted by 20 seconds into the spare slot, 53
It is set to redial after 0 seconds. Similarly, if the copier assigned to the second slot cannot access the host computer 1 by dialing three times, redialing is performed 445 seconds after the slot start time. Similarly, if the copying machine assigned to the third, fourth, and fifth slots cannot access the host computer 1 by three dials, after 360 seconds,
It is set so that redialing is performed after 270 seconds and 190 seconds. If the copying machine 2 assigned to the sixth slot cannot access the host computer 1 by three dials, redialing is performed in a spare slot prepared immediately after the sixth slot. , JA
TE standards cannot be met. Therefore,
Further, it is set so that redialing is performed in the next spare slot. That is, the copier assigned to the sixth slot is operated by the host computer 1 by dialing three times.
If access to is not possible, redialing is performed 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, if the copying machine 2 assigned to each slot cannot access the host computer 1 by dialing four or more times, redialing is performed 575 seconds after the previous dialing. Thereafter, access from the copying machine 2 is accepted in the corresponding time zone (step S4).

The copying machine 2 is provided with a control unit 11 as shown in FIG. The control unit 11 includes a CPU, RA
It comprises a microcomputer system including M, ROM, various drivers and various IOs. The control unit 11 includes an input key unit 12 provided on an operation panel of the copying machine 2.
And the display unit 13 are connected. In the control unit 11, the storage unit 14 stores a time slot number assigned by the host computer 1, a time interval for redialing, and the like. Further, the control unit 11 includes an 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 unit 11 of the copying machine 2 includes a process as shown in FIG. Step S12
, It is determined whether or not the time of the internal clock of the copying machine 2 has reached the assigned time slot start time. If it is determined that the time slot start time has come, step S
Go to step 13. In step S13, the redial counter in the RAM is reset. Further, step S14
, The copier 2 gives a command to the connected modem and dials the host computer 1.

In step S15, it is determined whether connection to the host computer 1 is possible. Host computer 1
Is connected, the copying machine 2 transmits the operation data stored in the storage unit 14 to the host computer 1 (step S16). If it is determined in step S15 that the connection to the host computer 1 cannot be established due to the detection of the line busy, the process proceeds to step S17, and "1" is added to the redial counter. In step S18, the storage unit 1
4 is read out in accordance with the value of the redial counter. In step S19, it is determined whether or not the current time has reached the time for performing redial based on the time interval for performing redial read in step S18. When it is time to perform redial, the process shifts 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 allocated to one time slot accesses the host computer 1 when the set time slot allocation time comes (step S14). If there is no error between the internal clocks of the two copying machines 2, the host computer 1 is accessed at the same time. When one copier 2 is connected to the host computer 1, the other copier 2 detects a line busy and redials after 20 seconds which is the line occupation time during communication of one copier 2 (step). S14). Therefore, assuming that there is no error in the internal clocks of both copying machines 2 and that the line connection time is 10 seconds, predetermined communication ends 30 seconds after one copying machine 2 accesses host computer 1, and then the other. If the copying machine 2 is connected to the host computer 1 via a line and communication is completed in 20 seconds, it takes 60 seconds for both copying machines 2 assigned to one slot to end predetermined communication.

Assuming that the error of the internal clock of the copying machine 2 is 15 seconds, one of the copying machines 2 will be connected to the host computer 1 15 seconds after the start time of the assigned time slot.
Is started (step S14). At this time,
Assuming that the line connection time is 10 seconds and the communication time is 20 seconds, it takes 45 seconds for one of the copying machines 2 to end the communication. During this time, the other copying machine 2 detects the line busy with the first dial, and redials 30 seconds after that (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 complete the predetermined communication. Therefore, when there is no interrupt communication in the host computer 1, it takes 60 seconds at the minimum and 75 seconds at the maximum for the copier 2 assigned to one time slot to perform predetermined periodic communication. Becomes Since one time slot is set to, for example, 85 seconds,
If there is no interrupt communication in the host computer 1,
The copying machine 2 assigned to each time slot can complete communication with the host computer 1 in that time slot.

When the copying machine 2 dials the host computer 1 within one time slot and detects a line busy by interrupt communication or the like, the two copying machines 2 perform redialing after 30 seconds. (Step S14). Here, 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 copier 2 redials after another 20 seconds to detect a line busy even at the second dialing (step S14). At this time, since the communication of one of the copying machines 2 has been completed, the time from the first dialing is 9 minutes.
After 0 seconds, the communication is completed. 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 there is a 15-second error in the internal clock of each copying machine 2, each copying machine 2 that detects busy due to interrupt communication at the time of the first dialing redials 45 seconds after the start time of the assigned time slot ( Step S14). At this time, one copier 2
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
Is that the line busy by one of the copying machines 2 is detected at the time of the second dialing, and the time for performing the third dialing is 75 seconds after the start time of the time slot. Here, the maximum connection time required for line connection is assumed to be 10 seconds.
The time during which 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 is connected before the copying machine 2 assigned to the next time slot accesses the host computer 1. Is possible.

In this case, it takes 10 minutes for the copying machine 2 assigned to one time slot to complete the periodic communication.
It takes 5 seconds and will go 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), a line busy is detected at the time of 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, in this case, too,
The time required for one copier 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.

The time required for the copying machine 2 assigned to each time slot to complete access to the host computer 1 is shifted by a maximum of 20 seconds at a maximum.
The shifted time is absorbed by the spare slot prepared next to the time slot. Therefore, if there is an interrupt communication in the host computer 1, if the interrupt communication is performed within 20 seconds, each copying machine 2 can surely access the host computer 1 by dialing up to three times. Will also be satisfied.

If the interrupt communication to the host computer 1 has occurred for 20 seconds or more, the copying machine 2 assigned to one time slot
Even if the user dials twice, the host computer 1 may not be accessible. In such a case, the copying machine 2 that could not access the host computer 1 is set to automatically perform communication in the spare slot time zone.

When a time slot as shown in FIG. 4 is set, if the copying machine 2 assigned to the first slot cannot access the host computer 1 by three dials, the first time slot is started. 51 from time
The host computer 1 is accessed using the time slot of the spare slot existing after 0 seconds. At this time, taking into account the shift time of 20 seconds by the copying machine 2 assigned to the sixth time slot, 5 seconds from the start time of the first 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 cannot access the host computer 1 by three times of dialing, 445 each. Seconds later,
Redial is performed after 360 seconds, 275 seconds, and 190 seconds.

If the copying machine 2 assigned to the sixth time slot cannot access the host computer 1 by three times of dialing, if the dialing is performed in the time slot of the next spare slot, three times within three minutes. The dial will be performed more than once, which does not satisfy 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 performs the fourth dial after 680 seconds.

In this embodiment, since the dial tone detection time and the dial time during communication are fixed values, they are ignored. Although a certain period of time is required for line busy detection, the redial interval is set to 30 seconds, and since the line busy detection time is shorter than the redial time, it can be ignored. In the present embodiment, the length of the time slot to which the two copying machines 2 are assigned is (the maximum error expected in the internal clock of the copying machine 2) +
(Maximum connection time estimated to be required for line connection + Maximum communication time estimated to be required for communication) * (Number of assigned copiers 2) + (Maximum connection time estimated to be required for line connection) Since the setting is made, the two assigned copying machines 2 can efficiently access the host computer 1 within the time slot. Further, even when interrupt communication to the host computer 1 is performed within the allocated time slot, each copying machine 2 can access the host computer 1 by dialing within three times, and the host computer 1 can be accessed in the shortest time. Communication with the computer 1 can be completed. Further, even when access cannot be made within the assigned time slot, communication with the host computer 1 is possible using the spare slot, and the host computer 1 of the copying machine 2 assigned to the next time slot can be communicated with. It does not hinder access. Moreover, dialing more than three times within three minutes is eliminated, and the JATE standard can be satisfied.

When a public line is used as a communication line, initial costs can be reduced as compared with a case where a dedicated line is laid, and a long construction period is not required. Further, by allocating two or more copying machines 2 to one time slot, even when an error exists in the internal clock of each copying machine 2, the blank time of access in the time slot is reduced, A decrease in communication efficiency can be avoided.

[Other Embodiments] (a) In the above-described 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 the dial time peculiar to each copying machine 2, it is also possible to set the time to dial the host computer 1 earlier by the time. (B) The time slot configuration of the host computer 1 may be a table as shown in FIG.

Here, three copying machines are assigned to the first to sixth time slots, respectively. The time required for the copiers assigned to each time slot to sequentially access the host computer 1 and complete the communication is as follows: the line connection time is less than 10 seconds, and the maximum communication time required for communication is 20 seconds. (10 + 20) * 3 = 90 seconds. If the maximum error estimated in the internal clock of the copying machine 2 is 15 seconds, the communication between the three copying machines is completed in 105 seconds. Here, lastly, host computer 1
In this case, the copier 2 that communicates with the user dials three times within the assigned time slot. If the host computer 1 cannot be accessed even after dialing three times due to interrupt communication or the like to the host computer 1, redialing should be performed after another 20 seconds.
TE standards cannot be met. Therefore,
If access to the host computer 1 cannot be performed by these three dials, access to the host computer 1 is executed in a spare slot prepared after the sixth slot. Thus, the first to sixth time slots are each set to 105 seconds. In this case, since the communication time of the copying machine 2 allocated to the sixth slot is not shifted, the spare slot is the maximum error estimated in the internal clock of the copying machine 2 and the maximum connection estimated to be required for line connection. The time can be set to 45 seconds in consideration of only the time and the maximum communication time expected to be required for communication.

If the copying machine 2 assigned to the first to sixth time slots detects a line busy when accessing the host computer 1, the copying machine 2 sends the signal to the host computer 1 again at a redial interval as shown in FIG. Access. That is, the first and second redial intervals are common to each time slot, and redial is performed 20 seconds after the line busy detection. In the third redial, the host computer 1 in the spare slot
, And the redial interval of the copying machine 2 assigned to the first to fifth slots is 525 seconds after the time slot start time.
Seconds, 420 seconds, 315 seconds, and 210 seconds. However, if the copier assigned to the sixth slot redials in the spare slot prepared immediately after, the JAT
The standard of E cannot be satisfied. Therefore, the host computer 1 is accessed in the next spare slot. Therefore, the time interval at which the copying machine 2 allocated in the sixth slot performs the third redial is 780 seconds after the time slot start time.

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

[0041]

According to the present invention, the length of the time slot to which the image forming apparatus is allocated is determined by the maximum error estimated in the internal clock of the image forming apparatus, the maximum connection time estimated to be required for line connection, and the communication. Is set based on the estimated maximum communication time required and the number of assigned image forming apparatuses, so that the assigned image forming apparatuses can efficiently access the management apparatus within the time slot. Becomes Further, even when interrupt communication to the management apparatus is entered 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 if access is not possible within the assigned time slot, communication with the management device is possible using the spare slot, and the image forming device assigned to the next time slot can access the image forming device. It does not hinder access. Moreover, the length of the time slot is set based on the internal clock error, the maximum connection time, the maximum communication time, etc.
TE standard can be satisfied.

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 access blank time in the time slot is reduced. And the communication efficiency can be prevented from lowering.

[Brief description of the drawings]

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

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 one embodiment of the present invention.

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

FIG. 6 is an explanatory diagram of a redial interval management table used in one 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]

 DESCRIPTION OF SYMBOLS 1 Host computer 2 Copy machine 3 Public line 4 CPU 11 Control part

Continuation of the front page (72) Inventor Hiroyuki Inaka 1-2-2, Tamazo, Chuo-ku, Osaka-shi Inside Mita Kogyo Co., Ltd. (72) Inventor Katsunori Masai 1-2-28, Tamazo, Chuo-ku, Osaka Mita Kogyo Co., Ltd. (56) References JP-A-6-131278 (JP, A) JP-A-5-176027 (JP, A) JP-A-61-114643 (JP, A) (58) Fields investigated (Int. Cl. ^7, DB name) G03G 21/00 370 - 540 G03G 15/00 303 G03G 21/02 - 21/04 H04M 11/00 - 11/10 G06F 13/00 351 - 357

Claims (1)

(57) [Claims] An image forming apparatus comprising: a plurality of image forming apparatuses; a management apparatus; and a communication line connecting the image forming apparatus and the management apparatus, and a time zone for accessing the management apparatus is assigned to each of the image forming apparatuses. Slot allocation means for preparing a reserved time slot and an unallocated spare slot, and allocating a next access time when the image forming apparatus detects a busy state of the management apparatus when accessing the management apparatus. Redial time management means for managing the allocated time slot and the spare slot prepared after the time slot; and access from the image forming apparatus to the management apparatus within the time slot allocated by the slot allocation means. And when it is detected that the management device is talking, based on the next access time, Access means for executing access from the image forming apparatus to the management apparatus, wherein the length of the time slot is the maximum connection time expected to be required for line connection and the maximum communication expected to be required for communication Multiplied by the number of image forming apparatuses assigned to the time, and further determined by adding the maximum error expected to the internal clock of the assigned image forming apparatus and the maximum connection time expected to be required for line connection, The length of the spare slot includes the time interval from the start time of the spare slot to the start of access, the maximum error estimated in the internal clock of the image forming apparatus, the maximum connection time expected to be required for line connection, and the time required for communication. Then, the redial time management unit further includes the predicted maximum communication time. In the case where it is detected that a call is not being made by the management device in the time slot and access is not possible, and when the time exceeds 3 minutes from the time when the access was not possible first, the next access time is used in the spare slot immediately after the time slot. And when accessing the time slot of the spare slot immediately after the time slot, when the third re-access is to be performed within three minutes from the time when the first access was not possible, the spare slot immediately after the time slot is used. A communication management apparatus for an image forming network, wherein the next access time is allocated in the next spare slot.