JPH0243569A - Abnormality monitoring device for office equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application 1'F] The present invention relates to abnormality monitoring of office equipment such as copying machines, and particularly to abnormality monitoring in office equipment equipped with a plurality of mutually independent control units such as microcomputers. related to load control at times.

[Prior Art] Office equipment 2, such as copying machines, facsimile machines, printers, etc., are often equipped with microcomputers (hereinafter referred to as CPUs) as control devices, and especially recently, one device has three or more CPUs. It is not uncommon for some to be equipped with the following.

By the way, in this type of office equipment, electric motors, lamps, heaters, etc. are installed as loads for the control device, but these loads can only be damaged themselves if abnormal control is performed. However, the heat generated by it may cause damage to various other equipment installed on the device or cause a fire. Therefore, devices of this type are provided with various safety devices.

A phenomenon called runaway, in which the CPU performs an abnormal operation that is completely different from the normal program content, may occur. - If a runaway occurs, normal operation cannot be restored unless a reset signal is applied to return the program execution to its initial state.

Therefore, conventionally, in devices using a CPU as a control means, the presence or absence of runaway has been monitored by the following method.

(1) Use dedicated hardware such as a watchdog timer to monitor pulse signals periodically output by the CPU.

(2) The pulse signal that the CPU periodically outputs is transferred to another CPU.
Monitored by PU.

When runaway is detected, a reset signal is conventionally applied to the CPU to initialize the operation of the CPU.

[Problems to be Solved by the Invention] However, when a reset signal is applied to the CP tJ while it is performing a write operation to the memory,
If abnormal data is written to the memory and the memory is not cleared by initialization of the CPU, an abnormality will occur in subsequent control.

Also, when using multiple CPUs, the C
A device has also been proposed in which a monitoring CPU separate from the PtJ monitors the state of the load, and when an abnormality occurs in the load, the monitoring CPU shuts off power to the load. However, in this type of device, a special electric circuit must be added in order for the monitoring CPU to monitor the state of the load, making the device configuration complicated.

The present invention is designed to prevent abnormalities such as runaway in the #J control device.
The purpose is to prevent disasters and failures caused by abnormal heat generation of loads, and to avoid complicating the configuration of the device.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a first control means and at least one load connected to an output terminal of the first control means via a gate means. and a second control unit that performs control independent of the first control unit, and monitors the operation of the slave control unit in case an abnormality occurs in the first control unit. a master control unit applying a de-energizing signal to the gate means to inhibit energization of the load;
will be established.

[In other words, in the present invention, the CP of the master control unit
U monitors the operation of the CPU of the slave control unit to identify the presence or absence of an abnormality, and if an abnormality is detected, the CPU of the master control unit directly controls the gate means of the slave control unit, Cut off power to the load. Thereby, even if the CPU of the slave control unit goes out of control, it is possible to reliably prevent the load connected to it from overheating.

In a preferred embodiment of the invention, which will be described below, information is transmitted between a master control unit and a slave control unit, and the time interval at which information is received is measured, and when the time is over a predetermined time, the platform is notified. There is an abnormality in the control unit of the transmission aa.

Other objects and features of the present invention will become clear from the description of the embodiments with reference to the following five drawings.

[Embodiment] The following description will be made with reference to FIG. 2, which shows one type of copying machine embodying the present invention. Briefly speaking, this copying machine consists of a copying machine body, an ADF (automatic document feeder) 60.
Sorter 70. It is composed of a group of optional units such as an automatic double-sided processing unit 80. The paper feed system that supplies recording sheets has five stages. That is, the first paper feeding system and the second paper feeding system are provided in the main body of the copying machine, and the second paper feeding unit 170, which is the third paper feeding system, and the third paper feeding system, which includes the fourth paper feeding system and the fifth paper feeding system, 3 paper feed unit 180 is connected to the main body of the copying machine. 21, 22, 23 and 24 are the first paper feeding system, respectively;
These are cassettes provided in the second paper feeding system, the third paper feeding system, and the fourth paper feeding system, and 25 is a tray of the fifth paper feeding system.

A contact glass l on which a document is placed is provided at the top of the main body of the copying machine, and an optical scanning system 30 is provided below the contact glass l. The optical scanning system 3o includes an exposure lamp 31. First mirror 32. Third mirror 33° Fourth mirror 34. lens 3
5. A fifth mirror is provided with a 36° slit 37, etc. When performing document reading scanning, a first carriage equipped with an exposure lamp 31 and a first mirror 32 and a second carriage equipped with a third mirror 33 and a fourth mirror 34 are arranged so that the optical path length does not change. Mechanically scan driven at a 2:1 relative speed. The lens 35 is a zoom lens, and its magnification can be changed by driving a motor.

Therefore, the light emitted from the fi light lamp 31 is transmitted to the first mirror 3.
2. Third mirror 33. Fourth mirror 34. Lens 35. An image is formed on the photosensitive drum 2 via the fifth mirror 36 and the Surins 1-37.

Around the photoreceptor drum 2, there are a main charger 3 and an eraser 4. Developing device5. Pre-transfer static elimination lamp 6, transfer charger 7, separation charger 8. It is equipped with a dangling unit 9, etc.

The image reproduction process will be briefly explained. The surface of the photosensitive drum 2 is uniformly charged to a predetermined high potential by the discharge of the main charger 3. The charge in the portion not used for image reproduction is erased by the eraser 4. When the charged surface of the photoreceptor drum 2 is irradiated with reflected light from the original, the
The photosensitive drum 2 rotates in the direction shown by the arrow in the figure, and the optical scanning system 30 sequentially scans the surface of the document in synchronization with the rotation of the photosensitive drum 2, which changes (decreases) the potential of that part depending on the intensity of the light. Therefore, on the surface of the photosensitive drum 2, a potential distribution corresponding to the density (light reflectance) distribution of the original image, that is, an electrostatic latent image is formed.

When the portion on which the electrostatic latent image is formed passes near the developing device 5,
The toner in the developing device 5 is attracted to the surface of the photoconductor 2 according to the potential distribution, and an electrostatic latent image is thereby developed, and a visible image corresponding to the electrostatic latent image is formed on the photoconductor 2. is formed.

On the other hand, in synchronization with the progress of the copying process, recording sheets are supplied from one of the five paper feeding systems selected. This recording silt is fed through the registration roller 27 at a predetermined timing so as to overlap the surface of the photosensitive drum 2.

The transfer charger 7 transfers the visible image (toner image) on the photoreceptor drum 2 onto the recording sheet, and the separation charger 8 separates the recording sheet to which the visible image has been transferred from the photoreceptor drum 2. 14. The separated recording sheet 1- is conveyed to a fixing device 12 by a conveyor belt 11. After passing through the fixing device 12, the toner image on the recording sheet is fixed onto the recording sheet by heat within the fixing device 12. The recording sheet that has been fixed is discharged to the sorter 70 or the automatic duplex unit 1-80 through a predetermined paper discharge path.

FIG. 3 shows the appearance of the operation board arranged on the top surface of the main body of the copying machine shown in FIG. Referring to FIG. 3, this operation board has a large number of key switches Kl.

K2. 3. 4ri, 4b, 5. 6a.

K6tz K7+ K8+ K9a, 9b, 9e.

KIO, Kl 1. 12a, 12b, 13°KC
, KS, #, KI and KT and a number of indicators DI, D
2. D3. D4. D5. Equipped with LED etc.

FIG. 1 shows an outline of the configuration of a control system for the copying machine shown in FIG. 2. Referring to FIG. 1, this control system generally consists of three units 100, 200 and 300. 100 is a main control board, 200 is an operation board, and 300 is an optical system control board, and each board is equipped with an independent microcomputer 1.
10°210 and 310 are provided.

The microcomputer 210 of the operation board 200 has one display control circuit 230. Key switch matrix 240. Lamp control circuit 250. It is connected to the heater control circuit 260, etc., and is used for display control of the display unit 1-220 (indicator DI, D2.D3°D4.D5.LED shown in FIG. 3), status reading and scanning control of various key switches, It performs dimming control of the exposure lamp 31, temperature control of the heater provided in the fixing device 12, and the like.

Microcomputer 310 of optical system control board 300
is connected to the RAM (read/write memory > 320, motor control circuits 330, 340, driver 360, etc., and performs reciprocating scanning drive control of the optical scanning system 30, copy image magnification control, image erasing control, etc.). The electric motor M2 that drives the scanning system 30 is an electric motor that adjusts the magnification of the lens 35 of the optical system.A battery is connected to the power supply circuit of the RAM 320, so that when the power of the copying machine is turned off, However, it is configured to retain its memory contents.

The control elements of the copying machine other than those mentioned above, such as the main motor, paper feeding mechanism, conveyance mechanism, paper ejection mechanism, various image reproduction process elements, fans, various optional units, etc., are controlled by the microcomputer 110 of the main control board 100. Ru. Signals from the sensor group 130 provided in each part of the copying machine are applied to the microcomputer 11α via a signal processing circuit 180, respectively. Solenoid, clutch.

Loads such as fans are connected to the microcomputer 110 via a driver 190. The high voltage power supply unit 120 includes a main charger 3°, a transfer charger 7,
It is connected to the bias electrodes of the separation charger 8 and the developing device 5, and supplies a predetermined high voltage or current necessary for the image reproduction process to these electrodes at a predetermined timing.

In this embodiment, the high-voltage power supply unit 120 adjusts the voltage or current value by pulse width control (pwM), and the signal that determines this pulse width is generated by the programmable timer 160.

A RAM (read/write memory) 150 equipped with a battery backup circuit is connected to the microcomputer 110 . This RAM 150 has.

Numerical values for determining various voltages and currents generated by the high-voltage power supply unit 120, numerical values for setting the light intensity of the FI light lamp, numerical values corresponding to the set temperature of the fixing heater, etc. are stored.

In addition, the microcomputer 110 of the main control board
is connected to the microcomputer 210 of the operation board and the microcomputer 310 of the optical system control board via a serial communication line so that information can be transmitted to each other.
connected with them.

That is, the serial signal transmission port TxD of the microcomputer 110 is connected to the serial signal reception port RxD of the microcomputer 310 via the gated buffer Glb and the buffer G3b, and the gated buffer G3. e and buffer G2c,
It is connected to the serial signal receiving port RxD of the microcomputer 210, and the serial signal receiving port RxD of the microcomputer 110 is connected to the serial signal transmitting port TxD of the microcomputer 310 via the gated buffer Glc and buffer G3a. It is also connected to the serial signal transmission port TxD of the microcomputer 210 via the gated buffer Glf and the buffer G2b.

The output port SEL of the microcomputer 110 is connected to the gate terminals of the buffers Glb, Glc, Gla, and Glf, and when SEL is at a high level H, the buffer G
When the gates of lb and Glc are open and the gates of Ole and Glf are closed, and SEL is at a low level L, the buffer Glb
The gates of Ole and Glf are closed, and the gates of Ole and Glf are opened. That is, when SEL is [■], communication between the microcomputers 110 and 310 is enabled, and when SEL is L, communication between the microcomputers 110 and 210 is enabled.

In addition, the output port PAO of the microcomputer 110
is connected to the optical system control board 300 via the buffer G1d.
The output port FAI is connected to the buffer Gla
It is connected to the operation board 200 via. The signal REST3 output from the output port PAO of the microcomputer 110 is used to inhibit the energization of the electric motor M1 for driving the scanner and the electric motor M2 for adjusting the lens magnification provided on the optical system control board 300, and is output from the output port PAI. The signal RESC output from the operation board 2
It is used to control the energization prohibition of the exposure lamp and fixing heater provided in the 00.

The details of the circuit configuration regarding these energization prohibition controls are shown in FIG.

This will be explained with reference to FIG. Signals 5FWD, 5RVS, and LMON output from the output port of the microcomputer 310 of the optical system control board are signals for driving the scanning motor M1 in the forward scanning direction and signals for driving M1 in the backward scanning direction, respectively.

and a signal for driving the lens motor M2.
The two signals are each connected to a three-state buffer G 3 c
, G3d and G3e to a driver circuit (not shown). Three-state buffer G3c
, G3d, and G3e, a control signal RESB from the main control board 100 is commonly applied.

Therefore, when the control signal RESB is set to low level 4, the three-state buffers G3c, G3d and G3e
gates are turned off and their output terminals are set to high impedance. In that case, since the output terminal of each three-state buffer is pulled up to the power supply line via a resistor, that terminal is set to a high level (3). In this example.

Three-state buffer G 3 c, , G 3
When the output terminals of d and G3e become H, the electric motors Ml and M2 are de-energized.

In other words, the microcomputer 11 of the main control board
0 outputs L to its output port PAO, power to M1 and M2 is cut off regardless of the control state of the microcomputer 310 of the optical system control board.

In addition, the signals LPON and 1-I T output from each output port of the microcomputer 210 on the operation board
ON is a signal that turns on the exposure lamp and the fixing heater, respectively. These signals are applied to lamp and heater driver circuits (not shown) via three-state buffers G2d and G2e, respectively. The control signal RE from the main control board 100 is applied to the gate terminals of the three-state buffers G2d and G2e.
SC is commonly applied.

Therefore, when the control signal RESC is set to a low level L, the gates of the three-state buffers G2d and G2e are turned off, and their output terminals are set to high impedance. In that case, since the output terminal of each three-state buffer is pulled up to the power supply line via a resistor, that terminal is set to high level II. In this example, when the output terminals of the three-state buffers G2d and G2e become H, the exposure lamp and the fixing heater are de-energized.

In other words, the microcomputer 11 of the main control board
0 sets its output port PAI to L, regardless of the control of the microcomputer 210 on the operation board.
Power supply to the exposure lamp and fixing heater is prohibited. Therefore, even if the microcomputer 210 goes out of control, the microcomputer 1 on the main control board
If 10 sets the signal RESC to L, the exposure lamp and fixing heater can be de-energized to prevent them from overheating.

In this embodiment, the microcomputer 110°210
and 7811G manufactured by NEC Corporation is used as 310. An outline of the internal configuration of this microcomputer is shown in FIG. 4.6 Referring to FIG. 4, this microcomputer includes an oscillation circuit OSC, a serial I10 circuit Bl, an interrupt control circuit B2. Timer circuit B3. Timer/
Event counter circuit 84. A/D conversion circuit BS, register B6. IΣPROM memory 137. RAM memory B
8 and other various control blocks necessary for processing.

The serial I10 circuit B1 has a serial data input terminal R.
A transmitting section includes three terminals: xD, serial data output terminal TxD, and serial clock input/output terminal SCK, as well as an 8-bit serial register, a buffer register, and a transmission/reception control circuit (not shown).

It consists of a receiving section and a mode register that specifies the operating mode. Note that each terminal RxD, TxD, and SCK is shared with ports Pct, PCO, and PC2, respectively.

The transmitting buffer register generates an interrupt request INTST when internal data becomes empty, and the receiving buffer register generates an interrupt request signal INTSR when the internal data is fully stored.

The three microcomputers 110°210 in Figure 1,
The outline of the data transmission procedure performed between 310 and 310 is shown in
As shown in the figure. This will be explained with reference to FIG. In this embodiment, the microcomputer of the main control board 100 first initiates data transmission processing for the entire system, and then data transmission is repeated between the system microcomputers in a chain.

In other words, the microcomputer 110 first
When EL is set to a high level H and data is transmitted, the data is received by the microcomputer 310 of the optical system control board 300. microcomputer 310
When it receives the data, it executes the interrupt processing described later in response to the interrupt request signal INTSR generated internally, processes the received data, and sends its own internal data to the main control board. It is transmitted to the microcomputer 110. Upon receiving this data, the microcomputer 110 of the main control board executes interrupt processing to be described later in response to the interrupt request signal INTSH, processes the received data, and outputs L to the output port SEL. , in turn transmits its own internal data to the microcomputer 210 of the operating board. When the microcomputer 210 receives the data, it executes interrupt processing to be described later in response to the interrupt request signal INTSR, processes the received data, and transfers its own internal data to the microcomputer 110 of the main control board. Send to.

By repeating the above operations, the main control board 10
0. Data is transmitted and received repeatedly in order between the optical system control board 300 and the operation board 200, and the transmitted data is used to manage the control of the entire system. It is also used to detect abnormalities such as runaway of the programmer 11 of the microcomputer on the control board.

The operations of each microcomputer mainly related to communication control will be explained below. 6a, 6b and 6c show the operation of the microcomputer 110 of the main control board, and FIGS. 7a and 7b show the operation of the microcomputer 210 of the operation board 200. In addition, the microcomputer 3 of the optical system control board
The communication-related operations of 10 are the same as those of the microcomputer 210 of the operation board, so 1 is not shown.

First, with reference to FIG. 6a, the microcomputer 110
Explain the operation. After performing initialization (not shown), first, in step 1, output ports PAO and PAI are each set to 1.
(corresponding to high level H), then in step 2 set the output port SEL to high level H, and then in step 3
transfers the internal data to the B unit, that is, the optical system control board 30.
Then, in step 4, the internal timer B3 is set to a predetermined value and started.

When the above processing is completed, the main processing routine of step 5 is repeatedly executed to perform various controls necessary for normal operation of the copying machine. However, even if the main processing routine is being executed, in this embodiment, if the serial I10 circuit Bl receives data, the reception interrupt request signal I
Since an NTSR occurs and interrupts are enabled during initialization, the process shown in FIG. 6b is immediately executed as an interrupt process in response. Further, when the timer B3 set in step 4 times out, a timer interrupt request signal is generated, and in response to the timer interrupt request signal, the timer interrupt process shown in FIG. 6c is immediately executed. However, timer B3 times out only when an abnormality is detected.

The reception interrupt processing shown in FIG. 6b will be explained.

In step 6, the operation of timer B3 is stopped and its count value is cleared to 0, and in step 7, timer B3 is restarted.

In step 8, the received data stored in the receive register of the serial I10 circuit B1 is processed, the type of the data is identified, and the data is stored in a memory at an address determined according to the type.

In step 9, the state of the output port SEL is checked. S
If EL is I], proceed to step 10; otherwise proceed to step 12.

If data transmission with the optical system control board 300 was performed in the previous process, then in step 10.

Switch output port SEL to L. Additionally, if data was being transmitted with the operation board 200 in the previous process, step 12 is executed and the output port SEL is set to I(
Switch to

After step 10, the process proceeds to step 11, in which 1 byte of data prepared in advance is transmitted to the C unit, that is, the operation board 200.

After step 12, the process proceeds to step 13, in which 1 byte of data prepared in advance is transmitted to the B unit, that is, the optical system control board 300.

After each step 11 or 13 is executed, the interrupt process is terminated and the process returns to the process shown in FIG. 6a. Main control board 1
There are a large number of data that 00 sends to the optical system control board 300 and the operation board 200, and each time the process of step 11 or step 13 in FIG. 6b is executed,
Bytes are sent in sequence.

As shown in FIG. 5, the main control board 100.

Data is transmitted to the optical system control board 300 and the operation board 200 repeatedly at substantially regular intervals, and when they are operating normally, the optical system control board 300 transmits data to the main control board 100. Immediately upon receiving the data from the optical system control board 300, the data from the optical system control board 300 is sent back to the main control board 100. Similarly, the operation board 200 sends the data of the operation board 200 back to the main control board 100 immediately after receiving the data from the main control board 100 .

In other words, there is no major change in the time required to execute the program during that time, so after the main control board 1°O sends data to the optical system control board 300 or the operation board 200, the main control board 100 The time Ttr until data is received from the control board 300 or the operation board 200 is approximately constant.

As shown in FIG. 6b, the timer B3 of the microcomputer 110 restarts the timer every time the reception interrupt process is executed.

The process from when the microcomputer 110 of the main control board sends data to the optical system control board 300 or the operation board 2°O until the microcomputer 110 receives data from the optical system control board 300 or the operation board 200 Count time.

The timer B3 is preset to a value slightly larger than the above-mentioned time "llr. Therefore, the microcomputer 2
If 10, 310 is operating normally, timer B
When the value of 3 reaches Tt,r, the reception interrupt process shown in FIG. 6b is executed and the timer B3 is reset in step 6, so the timer B3 does not time out.

However, if the operation of the microcomputer 310 on the optical system control board or the microcomputer 210 on the operation board goes out of control due to some abnormality, the microcomputer l1. Before O receives data from those computers, timer B3 counts a value that exceeds the set time and times out. In that case, a timer interrupt request is generated, and in response, microcomputer 110 executes the timer interrupt process shown in FIG. 6c.

This will be explained with reference to FIG. 6c. In this timer interrupt processing, first, in step 14, the state of the output port S E L is checked, and the state of the optical system control board 300 and the operation board 20 is checked.
0 and in which communication an error has occurred. If S E L is H, there is a high possibility that the microcomputer 310 of the optical system control board will go out of control, so the process proceeds to step 15 and outputs 0 to the output port PAO. That is, the control signal RESB is set to L, and the electric motors M1 and M2 provided in the optical system control board 300 are de-energized.

Also, if SEL is L, there is a high possibility that the microcomputer 210 on the operation board will go out of control, so step 1
Proceed to step 7 and output O to the output port FAI. In other words,
Set the control signal RESC to L.

Power to the exposure lamp and heater connected to the operation board 200 is cut off.

Regardless of whether an abnormality occurs in either the optical system control board 300 or the operation board 200, the process proceeds to step 16 and predetermined abnormality processing is performed. That is, the operator is notified of the occurrence of an abnormality, and the control states of various copy process elements are set to a standby state according to a predetermined procedure.

Next, the operation of the microcomputer 210 on the operation board will be described with reference to FIGS. 7a and 7b.

In normal processing, after initialization (not shown) is performed, an interrupt for data reception by the serial I10 circuit B1 is permitted in step 21, and the process proceeds to step 22. Step 22
Now, the display unit 220 provided on the operation board 200
Dynamic display control.

Key switch matrix 240 status reading control.

Executes each process of dimming control of the exposure lamp and temperature control of the fixing heater.

If interrupts are permitted in step 21, an interrupt request signal is generated when data from the main control board 100 is received, and in response, the reception interrupt process shown in FIG. 7b is executed.

In this reception interrupt processing, first, in step 31, subsequent reception interruptions are prohibited, in step 32, the received data is processed, and in step 33, the data on the operation board 200 is transferred to the A unit, That is, the main control board 100
Send to. When these processes are completed, step 7a
Return to the main routine processing shown in the figure.

In other words, when data is received from the main control board 100, the main control board 100 immediately responds to the received data.
The data on the operation board 200 is sent back to 00.

Although the operation of the microcomputer 210 on the optical system control board 100 is not shown in Figure 5, the operation is similar to that of the microcomputer 210 on the operation board in terms of data transmission. processes the received data and accordingly sends its own data back to the main control board 100.

[Effect] As described above, according to the present invention, when an abnormality such as runaway occurs in the control means provided in the slave control unit,
The master control unit detects this and prohibits one load connected to the slave control unit from being energized, so it is possible to prevent disasters and failures due to heat generation in the load. Moreover, since there is no need to detect the state of the load, there is no need to add a special circuit.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an electrical component of the copying machine shown in FIG. 2. FIG. FIG. 2 is a front view showing the structure of a mechanical section of a type of copying machine embodying the present invention. FIG. 3 is a plan view showing the appearance of an operation board provided in the copying machine shown in FIG. 2. FIG. FIG. 4 is a block diagram showing the internal configuration of each microcomputer shown in FIG. 1. FIG. 5 is a flowchart showing the procedure of data transmission between the plurality of control boards shown in FIG. 6a, 6b, and 6c are flowcharts outlining the operation of the microcomputer 110 of FIG. 1. FIG. 7a and 7b are flowcharts showing an outline of the operation of the microcomputer 210 of FIG. 1. FIG. FIG. 8 is an electrical circuit diagram showing a portion of the circuit of FIG. 1 in detail. 1: Contact glass 2: Photosensitive drum 4: Eraser 30: Optical scanning system 100: Main control board (mask control unit) 110, 210, 310: Microcomputer 110: (Second control means) 210, 310: (Second control means) 210, 310: (Second control means) 1 control means) 120: High voltage power supply unit 150: RAM 200: Operation board 200.
300: (Slave control unit) 220: Display unit 230: Display control circuit 240: Key switch matrix 250: Lamp control circuit 260: Heater control circuit 300: Optical system control board 320: RAM 330.340: Motor control circuit B1 real I10 Circuit B3: Timer circuit G2d, G2et G3c+ G3d+ G3e Nisley state buffer (gate means) RESB, RESC: Signal (deactivation signal) Fig. Fig. b Fig. 1, Incident display 2.9! Name of Ming 3, Person making the amendment Relationship with the case Address name Procedure amendment (method) % formula % Abnormality monitoring device for office equipment

Claims (1)

Claims: A slave control unit comprising a first control means and at least one load connected to an output terminal of the first control means via a gate means; and independent of the first control means. and a second control means for controlling the slave control unit, which monitors the operation of the slave control unit and applies a deactivation signal to the gate means when an abnormality occurs in the first control unit. An abnormality monitoring device for office equipment that includes a master control unit that prohibits energization of the load.