JPH05145600A - Image forming device having communication function - Google Patents

Abstract

PURPOSE:To allow a main body and a communication unit to detect whether or not the opposite party is normal at all times in the image forming device comprising the image forming device main body and the communication unit. CONSTITUTION:An image forming device main body 101 and a communication unit 102 are connected by an RS-232C. The communication unit 102 is connected to a host computer through a telephone line. When a communication check command is sent from the communication unit, the image forming device main body 101 returns an confirmation signal and discriminates whether or not the check command is sent for a prescribed period. When the period not receiving the check command takes place consecutively three times, it is discriminated that a fault takes place in the communication unit 102. On the other hand, the communication unit 102 sends periodically the check command to the image forming device main body 101. When the period not receiving the confirmation signal from the image forming device main body 101 takes place consecutive for three times, it is discriminated that a fault takes place in the main body 101.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a communication function.

[0002]

2. Description of the Related Art FIG. 4 shows a block diagram of a copying machine connected to a telephone line as an example of a conventional image forming apparatus having a communication function. The copier installed at the user's site includes a copier main body 41 and a PC / modem (modem for personal computer communication) 42.
Consists of. The main body 4 of the copying machine 41
In addition to 11, the communication interface 412 is provided. The modem 42 has a function as a normal modem of converting a digital signal into a signal band of a telephone line and transmitting it, and temporarily holding data sent from the copying machine main body 41 to the host computer 44 and editing the data. It has the function of doing. Data is exchanged between the interface 412 and the modem 42 by serial communication using RS-232C or the like. A host computer 44 that holds various data and edits them is installed in the service station.
A normal modem 43 is connected to the host computer 44, and data is exchanged between the host computer 44 and the modem 43 by serial communication. The modem 42 and the modem 43 are connected to the telephone line 45. The host computer 44 performs serial communication with the copying machine main body 41 through the modem 43, the telephone line 45, and the modem 42. Such a configuration is basically the same as the configuration for normal personal computer communication when the copying machine body 41 is replaced with a personal computer.

[0003]

However, in the conventional copying machine as described above, when unidirectional communication is performed from the copying machine main body 41 to the modem 42, whether the communication failure has occurred in the modem 42 or not. However, it cannot be judged on the copying machine main body 41 side. Further, the modem 42 cannot know that a communication failure has occurred on the copying machine main body 41 side unless data is not sent from the copying machine main body 41 for a certain period of time. Even when bidirectional communication is performed between the copying machine body 41 and the modem 42, it is only possible to confirm whether or not the partner device is normal at the time when the command is exchanged, and at other times. It cannot be confirmed.

Therefore, in the case of one-way communication, since communication is performed regardless of whether the device on the other side is normal or not, accurate data exchange cannot always be guaranteed. Further, in the case of bidirectional communication, it is not known whether the device on the other side is normal until the communication is actually performed, and therefore it is not possible to promptly deal with the occurrence of a failure.

An object of the present invention is to provide an image forming apparatus which solves such a problem, guarantees accurate data communication, detects a failure occurrence at an early stage, and can promptly deal with it. is there.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus having a communication unit connected to a telephone line, in which a predetermined check command is transmitted between the image forming apparatus main body and the communication unit. It is provided with means for periodically executing transmission and reply of a confirmation signal in response to the check command, and means for respectively determining whether or not the check command and the confirmation signal are received within a preset time. And an image forming apparatus having a communication function.

[0007]

The communication unit sends a check command to the image forming apparatus body at regular intervals, and the image forming apparatus sends a confirmation signal to the communication unit in response to the check command. The image forming apparatus main body determines that a failure has occurred in the communication unit when the check command is not received for a predetermined period. Moreover, the communication unit determines that a failure has occurred in the image forming apparatus when the confirmation signal is not received for a predetermined period.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows an example of an image forming apparatus having a communication function according to the present invention. This image forming apparatus includes an image forming apparatus main body 101 such as a copying machine and an RS-2 on the main body 101.
32C, and a communication unit 102 that connects the image forming apparatus main body 101 to a host computer (not shown) through a telephone line. In addition to the main control unit 103, the image forming apparatus main body 101 includes the main control unit 103 and the communication unit 1
An interface 104 for connecting to 02.

In the main control unit 103, 1
Is a microcomputer, which operates based on a program stored in the ROM 3,
1 Control the whole. SRAM 4 is used by the microcomputer 1 to temporarily store various data.
And is backed up by batteries. A SIO 5 is used by the microcomputer 1 to perform serial communication with the interface 104 and exchange data.
(Serial input / output port). Reference numeral 2 is a parallel input / output port for data input / output.

The level conversion circuit 6 of the interface 104 outputs a TTL level signal from the serial port 5 to the R level.
Communication unit 10 by converting to S-232C level signal
2 to the RS-2 from the communication unit 102
The 32C level signal is converted into a TTL level signal and output to the serial input / output port 5.

In the communication unit 102, 8 is an RO
It is a CPU (central processing unit) that operates based on a program stored in M9 and controls the entire communication unit. An SRAM 13 is used by the CPU 8 to temporarily store various data and is backed up by a battery. Reference numeral 7 converts the TTL level signal from the serial input / output port 10 into an RS-232C level signal and sends it to the level conversion circuit 6 of the image forming apparatus main body, while the RS-232C level signal from the level conversion circuit 6 is transmitted. Is a level conversion circuit for converting the signal of (1) into a signal of TTL level and outputting to the serial input / output port 10. Reference numeral 15 is a modem, which is connected to a telephone line via an NCU (line control unit) 16. Reference numeral 14 is a clock circuit for the CPU 8 to acquire time information. Reference numeral 11 is a power source for supplying electric power to each part of the communication unit, which is backed up by a rechargeable battery 12.

Next, the operation of the image forming apparatus main body 101 will be described.
This will be described with reference to the flowchart of FIG. First, in steps S201 to S203, the parameter N for time-up count is set to 0, and the flag parameter F indicating whether or not the communication function check command is received is set to 0,
Start timer T1. In step S204, it is determined whether or not a check command is received from the communication unit 102. If "NO", in step S207 the control of the image forming apparatus main body 101 and the communication unit 102 are performed.
Perform communication processing between. In step S208, it is determined whether or not the timer T1 has timed out, and if "NO", the process returns to step S204. On the other hand, in step S204, when the determination result is “YES”, step S2
At 05, a confirmation signal ACK is transmitted to the communication unit 102,
After setting the flag parameter F to 1 in step S206, the process proceeds to step S207. Steps S204 to S208 are repeatedly executed until the timer T1 times out.

The timer T1 has timed out, and step S
If the determination result in 208 is “YES”, step S
At 209, it is determined whether the flag parameter F is 1,
If "YES", it means that the check command is received before the timer T1 times out, so the parameter N is set to 0 in step S214, the timer T1 is initialized in step S213, and the step S213 is performed.
Return to 202. On the other hand, if the decision result in the step S209 is "NO", it means that the check command has not been received until the timer T1 times out, so that 1 is added to the parameter N in the step S210 and the parameter is added in the step S211. It is determined whether N exceeds 2. If this determination result is "NO", step S2
In step 13, the timer is initialized and then the process returns to step S202. In the case of "YES", it means that the check command has not been received before the timer T1 times out three times. Therefore, it is determined that a communication failure has occurred in the communication unit 102 or an intermediate path, and the failure processing is performed. A display indicating that communication with the communication unit 102 is impossible is displayed on a display unit (not shown) of the main body 101 (step S212).

Next, the operation of the communication unit 102 will be described with reference to FIG.
This will be described with reference to the flowchart in FIG. First, in steps S301 and S302, a parameter M for counting the number of time-ups is set to 0, and a timer T2 that determines a cycle for transmitting a check command to the main body 101 is started. In step S303, a communication check command is transmitted to the main body 101, and in step S304, a timer T3 that determines an allowable value for the time from transmitting the check command to receiving the confirmation signal ACK is started.

Next, in step S305, a confirmation signal ACK
Is sent from the main body 101, and “N
If "O", the process proceeds to step S306 to determine whether or not the timer T3 has timed out. If this determination result is "NO", the process returns to step S305. On the other hand, the determination result in step S305 is "YES". In the case of “”, communication processing with the main body 101 or a host computer (not shown) connected through a telephone line is performed in step S309, and then the timer T is used in step S310.
It is determined whether or not 2 has timed up. Step S309 is repeated until this determination result becomes “YES”.
When the determination result is “YES”, step S311
Then, the timer T2 and T3 are initialized and the process returns to step S302.

The determination result of step S306 is "YES".
In the case of
Since it has not been sent from S.3, step S3
At 07, 1 is added to the parameter M, and at step S308, it is determined whether or not the value of the parameter M exceeds 2. If the determination result is “NO”, the process proceeds to step S311. On the other hand, if the determination result is “YES”, it means that the check command has not been received before the timer T3 times up three times. Alternatively, it is determined that a communication failure has occurred on the route along the way, and in step S312 communication is performed to notify the host computer of the failure occurrence, and execution of a predetermined service for failure processing is prompted.

[0017]

According to the image forming apparatus having the communication function of the present invention, means for periodically transmitting a predetermined check command and returning a confirmation signal to the check command between the image forming apparatus main body and the communication unit. And means for determining whether or not the check command and the confirmation signal have been received within a preset time, it is possible to constantly monitor whether or not the other party is normal. Yes, therefore, accurate data communication can always be guaranteed, and failure occurrence can be dealt with promptly.

[Brief description of drawings]

FIG. 1 is a block diagram of an image forming apparatus having a communication function of the present invention.

2 is a flowchart showing the operation of the image forming apparatus main body of the image forming apparatus of FIG.

3 is a flowchart showing an operation of a communication unit of the image forming apparatus of FIG.

FIG. 4 is a block diagram of a conventional image forming apparatus having a communication function.

[Explanation of Codes] 1 Microcomputer 2 Input / output port 3, 9 ROM 4, 13 SRAM 5, 10 Serial input / output port 6, 7 Level conversion circuit 8 CPU 11 Power supply 12 Backup battery 14 Clock circuit 15 Modem 16 Line control unit 101 image forming apparatus main body 102 communication unit 103 main control unit 104 interface

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shigeo Kusumoto 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Inventor Jun Morimoto 22-22, Nagaike-cho, Abeno-ku, Osaka, Osaka Within the corporation

Claims (1)

[Claims] 1. An image forming apparatus having a communication unit connected to a telephone line, wherein a predetermined check command is transmitted between the image forming apparatus main body and the communication unit and a confirmation signal is returned in response to the check command. An image forming apparatus having a communication function, comprising: a unit that periodically executes a check command and a unit that determines whether or not the check command and the confirmation signal are received within a preset time.