JP2000105521A - Device consisting of a plurality of units and abnormality detecting method and initializing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To normally return the control of each unit even if a communication error occurs and perform a proper abnormality detection conformed to the characteristic of the unit by changing the criterion of judgment according to the kind of an extended unit when a main body unit judges the normality or abnormality of the extended unit from the communication with the extended unit. SOLUTION: The CPU 117 of a main body 101 transmits a command to each unit 106, 103, and receives the status from each unit 106, 103. The received status is checked for parity error or the like to judge the error. The error counter corresponding to the unit having no error is cleared to 0, and an increment is added to the error counter corresponding to the unit having the error. Whether the error counter exceeds a predetermined prescribed value or not every unit is checked. When the error counter exceeding the prescribed frequency is present, the state of the device is set to a communication abnormal state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention comprises a main unit capable of performing a predetermined function by itself and at least one additional unit connected to the main unit.
The present invention relates to an apparatus including a plurality of units, and particularly to an abnormality detection and initialization procedure.

[0002]

2. Description of the Related Art In recent years, copiers, fax machines, laser printers,
2. Description of the Related Art Image forming apparatuses such as page printers such as LED printers have been widely accepted in the market, and their functions have been increased. More specifically, the size and material of the non-recording material may be increased, and double-sided printing and a sorter function may be added.

However, if the number of paper feed units is increased in order to automatically switch the paper size, or if functions such as a double-sided printing function and a sorter function are increased, the apparatus becomes larger and the installation area becomes larger. However, there is a tendency to be expensive, and it is inconvenient for a user who uses only a limited paper size or a user who uses only a limited function, and when a user wants to further increase only a specific function. It is difficult to meet the needs of each user.

To solve this problem, a main unit capable of performing minimum printing alone, a paper feed unit for increasing the type and amount of paper to be handled, a unit for double-sided printing, a sorter mechanism, and the like are used. An extension unit may be provided, and the extension unit may be mounted on the main unit according to a user's request. Each extension unit is provided with a control device to manage and control the initialization operation and the like unique to the unit, and by communicating with the main unit, the whole device can be managed by the main unit.

However, communication errors such as a parity error may occur in communication between the extension unit and the main unit due to various factors such as extraneous noise and abnormalities of the extension unit itself. If a communication error occurs frequently, the main unit may not be able to perform normal control of the extension unit. Therefore, if a communication error occurs a plurality of times (for example, twice) continuously, the entire device is initialized. An instruction is issued and a return operation is performed so that the apparatus can be controlled. Alternatively, it is determined that there is an abnormality in any of the units or the communication system, and an abnormal state such as a failure occurs.

[0006] Also, due to external factors such as noise, only a specific unit malfunctions or becomes uncontrollable, and in some cases, only the CPU of the specific unit is reset. These abnormalities are monitored by the image forming apparatus main body.

[0007]

However, in the control for judging that an abnormality has occurred when a communication error has continued for a predetermined number of times, an abnormality is detected in order to prevent erroneous detection of an abnormality due to noise or the like. It is sufficient to increase the number of times. Conversely, if this number is increased, it is more likely that necessary commands cannot be instructed to the additional unit or that status from the additional unit cannot be received normally. There was a problem.

Conventionally, upon detecting the configuration of what kind of extension unit is connected when the power is turned on or immediately after the initialization instruction is issued to the entire apparatus, conventionally, the operation is started immediately after the operation is started. Or after a fixed amount of time,
The CPU of each unit starts communication and checks the configuration. However, as the number of types of extension units increases, a situation occurs in which some initialization units have a long time and some units have a short time. If you do not properly control the timing of starting communication and checking the configuration, you may not be able to recognize an extension unit that requires a long time for initialization processing or may not be able to communicate normally. Since there is a possibility, a waiting time with a sufficient margin is required until the start of the configuration check operation, and there is a problem that the initialization operation is lengthened.

[0009]

A first gist of the present invention is as follows.
In a device consisting of multiple units such as a printer main unit and its extension unit, when the main unit decides whether the extension unit is normal or abnormal by communicating with the extension unit, change the judgment criteria according to the type of extension unit. It is in.

A second gist of the present invention resides in that the main unit determines whether the extension unit is normal or abnormal by communicating with the extension unit, and changes the determination standard depending on the state of the main unit.

A third gist of the present invention is that, when initializing the entire apparatus, the main unit performs its own initialization after all the connected expansion units have completed their initialization.

A fourth gist of the present invention is that the main unit periodically communicates with all of the extension units, and when there is an extension unit that is in a communication disabled state, it is determined whether or not to perform a recovery process. The determination is to be made according to the duration.

A fifth gist of the present invention is that if a suspended extension unit becomes abnormal while the main unit and a part of the plurality of extension units are being processed, the additional unit which has failed after the processing is completed. It is to perform a unit return process.

According to a sixth aspect of the present invention, a main unit supplies a signal of a constant level to all of the extension units, and monitors an output signal level of the signal supply unit.
First initialization means for initializing the main unit when the signal level falls below the first level, the extension unit monitors an output signal level of the signal supply means, and outputs a second signal which is lower than the first level. An apparatus comprising a plurality of units, characterized by having a second initializing means for initializing an additional unit when the level becomes lower than level 2.

According to a seventh aspect of the present invention, a main unit includes:
Signal supply means for supplying a signal of a fixed level to all of the extension units, first initialization means for monitoring the output signal level of the signal supply means and initializing the main unit when the output signal level reaches a predetermined level; After the initialization is completed, the first unit has a first timer for waiting for a first time until the operation returns to the normal operation. The extension unit monitors an output signal level of the signal supply unit, and when the output signal level reaches a predetermined level. Second initialization means for initializing the corresponding extension unit, and second timer means for waiting for a second time shorter than the first time until the normal operation is restored after the initialization is completed. An apparatus comprising a plurality of units.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. The following embodiments will be described using the case where the present invention is applied to a page printer, but the present invention is also applicable to an apparatus having another plurality of units.

[First Embodiment] FIGS. 1 to 8 show a first embodiment of the present invention. FIG. 1 is a main part side view showing a configuration example of a page printer as an image forming apparatus to which the present invention can be applied.

Reference numeral 101 denotes a printer main unit (hereinafter abbreviated as a main unit or a main unit);
6 is an extension unit. Reference numeral 106 denotes a two-sided unit for reversing the sheet for double-sided printing, 102 denotes an upper sheet feeding unit (hereinafter, referred to as an upper feeder), 103 denotes a lower sheet feeding unit (hereinafter, referred to as a lower feeder). Is the same as

When a recording operation is started by a command from a computer (not shown) connected to the main body 101, the main body, the upper feeder 102 or the lower feeder 1 is operated in accordance with the command.
03 is fed to the conveyance path by the feed roller 105, and the image developed by the photosensitive drum 107 is transferred. Be established.

Reference numeral 123 denotes a flapper for switching the paper conveyance path. When printing is performed on only one side, the paper is conveyed to the discharge roller 109 and discharged from the discharge port 110. When performing double-sided printing, the sheet is conveyed to the double-sided unit 106. Reference numeral 111 denotes a conveyance path when paper is fed from below the main body 101, and includes a duplex unit 106, an upper feeder 102, and a lower feeder 1 attached below the main body 101.
This is for accepting a paper feed from the printer 03. In the duplex unit 106, reference numeral 124 denotes a flapper for switching the transport path of the paper, 121 denotes a transport path for re-feeding the paper with the transport direction reversed to the main body 101, and 116 denotes a CPU for controlling the duplex unit 106; Body 101
The CPU 117 communicates commands and signals representing states through the connection cable 120. In the present embodiment, the cables are used to connect the connectors, but the connectors may be directly connected to each other.

In the upper feeder 102, 104 is a recording paper, 113 is a paper feeding roller, 114 is a conveying path for receiving paper feeding from below, 115 is a conveying roller, and 116 is a CPU having the same function as the CPU of the duplex unit. (This function will be described later), and is connected to the CPU 116 of the duplex unit 106 by a connection cable 118.
Reference numeral 119 denotes an upper feeder 102 and a lower feeder 10.
3 is a connection cable for performing the communication.

The lower feeder 103 is also the upper feeder 102
Has the same configuration as, but because it is located at the bottom layer,
The CPU 116 is connected only to the upper feeder 102.

FIG. 2 is a diagram showing an electrical connection between the main unit and each extension unit in FIG. In the figure, the connection of the upper unit 102 is omitted for the sake of simplicity. Reference numeral 201 denotes a power supply device inside the main body 101, and a CPU
117 and the respective circuits 202. Power is also supplied to the duplex unit 106 and the feeders 102 and 103 through the connection connector 203 and the connection cable 120.

Double-sided unit 106, feeders 102, 1
In 03, reference numeral 204 denotes a connector for receiving a connection cable from the upper stage, and 205 denotes a connector for connection to the lower stage.
Reference numeral 06 denotes a terminator that is connected when the extension unit is not connected to the lowermost connection connector 205. 2
Reference numerals 07, 208, and 209 denote reset ICs, each of which has a CP.
By monitoring the voltage of the power supply supplied to U117, 116,
When the voltage falls below the predetermined voltage, the corresponding CPU 117, 116
Reset.

As will be described later, the Data in terminal and the Data out terminal of the CPU 116 are connected via a shift register, and serial data output from the CPU 117 of the main body in synchronization with the rising of the Clock passes through each CPU 116. When the signal reaches the terminator 206, it returns to the terminator 206 and transmits a loop-shaped path returning to the Data in terminal of the main CPU 117.

The duplex unit 106 and the feeders 102 and 1
03 has a structure as shown in FIG.
In the figure, reference numeral 301 denotes a communication shift register;
Is a communication data storage register. The serial data sent from Data in is shifted in the shift register 301 in synchronization with the rise of Clockin. When the data is determined, the CPU 117 of the main body 101
Send strobe signal to in.

Upon receiving the strobe signal, the CPU 116 replaces the data in the shift register 301 with the data in the communication data storage register 302 and analyzes the data as communication data. The signal at this time is shown in FIG. Referring to FIG.
The data is determined one bit at a time at the falling edge of the clock signal, the communication data is determined at the falling edge of the strobe signal at 402, and is stored in the register 302 in each CPU as indicated by arrows 403, 404, and 405.

Since the data transmission path is loop-shaped,
If the data is continuously output without outputting the strobe signal, the first sent data passes through the terminator 206 and is
It returns to Data in of PU117. By utilizing this fact, the CPU 17 of the main body 101 can know how many additional units such as feeders are connected by checking at what clock the data returns. That is, in this embodiment, since the shift register 301 of each CPU has a length of 8 bits, the first transmitted data is returned at 25 clocks. From the result, it is found that the total shift register length is 24 bits, which means that three units obtained by dividing 24 by 8 are connected.

When a strobe signal is received, the register 30
The information is transmitted from each unit to the main unit by utilizing the fact that the content of No. 2 is exchanged with the content of the shift register 301.
That is, by setting the status of each unit and the result corresponding to the command sent from the main unit in the storage register 302 in advance, data can be sent from each unit to the main unit 101.

The communication commands and status include:
By adding data such as parity data for detecting a communication abnormality, and checking whether there is any abnormality in the data, it can be confirmed whether the communication is normally performed.

Next, the initialization operation will be described. When the power of the main body 101 is turned on, the power is also supplied to each of the extension units, and the reset ICs of the respective devices are connected to the CPUs 117 and 1.
16 is reset, and when it is released, the CPU 117,
116 starts operation, and a control circuit (not shown) starts operation.

Next, the main body 101 transmits predetermined serial data (for example, one continuous data) as described above, counts the number of clocks until the data returns, and detects the number of connected extension units. Then, a command for inquiring what kind of device each device is transmitted to recognize the entire configuration. Thereafter, a command tailored to each device is transmitted and the received status is analyzed to monitor the status of each device.

FIGS. 5 and 6 are flowcharts showing the control relating to the communication control of the present embodiment, and FIGS. 7 and 8 are diagrams showing an example of the judgment of the abnormality of the extension unit according to the present embodiment.

FIG. 5 shows the CP of the main body 101 after the initialization is completed.
It is a flowchart which shows the outline | summary of the process of U117. S
Reference numeral 501 denotes processing for communicating with each unit, the details of which are shown in FIG. S502 is a print process as an image forming apparatus other than communication. Details of this processing are omitted because they are not directly related to the present invention.

FIG. 6 is a flowchart showing the detailed processing of S501. Before performing this process, a counter for the number of connected units (hereinafter referred to as an error counter) is prepared in advance on, for example, a RAM (not shown), and 0 is set as an initial value. Further, the number of continuous communication errors to be determined to be abnormal depending on the type of the unit is determined in advance and stored in a RAM or a ROM (not shown). For example, in the present embodiment, the number of duplex units is two, and the number of feeders is four. That is, if a communication error occurs twice for the duplex unit and four times for the feeder consecutively, it is determined that the communication is abnormal.

First, in step S601, processing for sending a command from the main body 101 to each of the units 106, 102 and 103 is performed. Then, the status is received from each unit in S602. In step S603, a data consistency check is performed to determine whether a parity error has occurred in the received status or whether a status having contents that should not be sent has been received. Determine if there is. The error counter corresponding to the unit having no error is cleared to 0, and the error counter corresponding to the unit having the error is incremented.

In step S604, it is checked whether each counter has exceeded a predetermined value predetermined for each unit. If there is an error counter exceeding a predetermined number in S604, the state of the device is set to a communication abnormal state in S606. If not, S6
The status received at 05 is stored in a predetermined area of a RAM (not shown) so that it can be referred to in the process of S502.

If the communication has become abnormal, S502
In the process (1), a failure state is set, the operation of all devices is stopped, and communication and initialization of each extension unit are instructed.

FIG. 7 shows a specific example of the abnormality determination according to the present embodiment.
This will be further described with reference to FIG. 7 and 8
Indicates the status of the status received by the CPU 117 of the main body 101 through communication between the n-th main body CPU and the duplex unit connected thereto and the upper and lower feeders. 7 and 8 show different communication states.

FIG. 7 shows that no error occurred in the communication of each unit in the n-th communication, but the (n + 1) -th communication
Continuously in the (n + 2) th communication, the duplex unit 106
Indicates that a communication error (parity error) has occurred. Thus, the duplex unit 106
Since an error has occurred twice in succession in communication with, communication error state is set in S606 in FIG.

In the example of FIG. 8, no error occurs in each unit in the n-th communication, and the (n + 1) -th and (n +
2) In the second communication, an error has occurred in the status received from the upper feeder 102 continuously. Thus, the value of the error counter corresponding to the upper feeder 102 becomes 2. In the present embodiment, the feeder does not generate a communication error four times in a row (unless the error counter reaches 4).
Since a communication error state is not set, a communication error state is not set at this time. Then, since there was no error in the status of the feeder 102 in the (n + 3) -th communication, the counter corresponding to the feeder 102 is cleared to zero. An error occurs in the communication of the feeder 102 continuously in the next (n + 4) th communication to the (n + 7) th communication, and the feeder 10
Since the error counter corresponding to 2 is 4 as described above, S
The process of 606 is performed, and a communication abnormal state is set.

Some expansion units require only simple control. Some units can be controlled without any problem even if a communication error occurs. Other units require fine timing control. Some units may not be able to perform normal control.

By performing the above-described configuration and control, it is possible to determine that an abnormality has occurred only when control of the extension unit cannot be performed. As a result, unnecessary abnormal detection can be minimized even when external noise is present.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIG. In the first embodiment, the number of continuous occurrences of the communication abnormality that is determined to be abnormal according to the type of the extension unit is determined. In the present embodiment, the continuous occurrence of the communication abnormality that is determined to be abnormal according to the state of the main unit is performed. The difference is that the number of times is determined, and that counting is continued if any one of the units causes a communication error. Since the configuration of the device may be the same as that of the first embodiment, the description is omitted.

FIG. 9 is a flowchart showing the control relating to the communication control of the present embodiment. The same processes as those in FIG. 6 of the first embodiment are denoted by the same reference numerals.

In this embodiment, one error counter is prepared in advance on a RAM (not shown), and 0 is set as its initial value. In addition, the state of the main unit is associated in advance with the number of continuous occurrences of the communication error which is determined to be abnormal, and stored in a RAM, ROM, or the like (not shown). In the present embodiment, the number of times is 10 in a standby state (standby state) in which no printing operation is performed, from the start of paper feeding operation for printing to the start of image formation on the photosensitive drum 107. Status (paper feed status)
It is assumed that the state from the start of image formation on the photosensitive drum 107 to the end of printing and the standby state (printing state) is set to four times in advance.

In S601 and S602, the same command / status transmission / reception processing as in the first embodiment is performed. S70
In step 1, for each of the received statuses, a check is made to determine whether a parity error has occurred or to check data consistency. If there is at least one error, the error counter is incremented by one, and if there is no error or the state changes, the error counter is cleared to zero.

Next, in step S702, a predetermined value for determining a communication error according to the current operation state of the entire image forming apparatus is obtained and stored in a variable "work". Therefore, the value stored in the variable work in S702 is one of 2, 4, and 10. In step S703, the value of the error counter is compared with the value of the variable work. If the value of the error counter is equal to or greater than the value of the variable work, the process proceeds to step S60.
At 6, the communication is abnormal. If not, the status received in S605 is stored in a RAM area (not shown) so that it can be referred to in the processing in S502.

In the operation state of the image forming apparatus, there is almost no need to control the extension unit unlike the standby state, and even if a slight communication error occurs, the actual operation of the image forming apparatus is not affected. In some cases, there is a possibility that a paper jam may occur unless detailed control is performed, such as in the paper feeding state.

By performing the above-described configuration and control, it is possible to determine that an abnormality has occurred only when the image forming apparatus cannot be controlled. As a result, unnecessary abnormal detection can be minimized even when external noise is present.

[Third Embodiment] FIGS. 10, 11, and 12
Shows a third embodiment of the present invention. FIG. 10 shows a main body 101, a duplex unit 106, and feeders 102 and 10.
3 shows an electrical connection between the two, and the same components as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted. Also,
The connection of the upper unit 102 is omitted for the sake of simplicity.

A signal 1001 indicates whether or not an additional unit is connected to the lower side of the feeder 103 (upstream of the paper transport path). If no unit is connected to the lower side as in the feeder 103, the signal 1001 is supplied. Since this signal is pulled down in the resistor 103 by the resistor R1, the “L (low)” level is input to the TRMT terminal of the CPU.
Similarly, the signals 1003, 1005, and 1007 are the feeder 102, the duplex unit 106, and the main body 101, respectively.
Is a signal indicating whether or not an extension unit is connected to the lower side.

The signal 1007 will be described in detail. If the extension unit is not connected to the lower side of the main body 101, the CPU 1
An “L” level is input to 17. In the present embodiment, since the duplex unit 106 is connected, the signal 1007
Is pulled up by a resistor R2 inside the double-sided unit 106. The resistance value of the resistor R2 is sufficiently smaller than the resistance value of the resistor R1 (R1≫R2). Therefore,
The signal 1007 is at the “H (high)” level, which is
The signal is input to the TRMT terminal of the PU 117. CPU 117 is TR
Since the MT terminal is at the “H” level, it can be recognized that some additional unit is connected to the lower side.

Signals 1002, 1004, 1006, 10
A signal 08 is used for recognizing each other's operation state between the adjacent extension units and indicating the operation state of the own unit. These signals are each pulled up by the resistor R3 in the upper unit (signal 10).
02 has no unit on the lower side, but when another additional unit is connected below the lower feeder, the lower unit becomes the upper unit.) For example, the signal 1008 is pulled up inside the main body 101.

The RDYup terminal of the CPU 116 is a terminal for monitoring the operation state of the upper unit of each unit and indicating the operation state of the own unit with respect to the upper unit. The RDYdwn terminals of the CPUs 117 and 116 are terminals for monitoring the operating state of the lower unit of each unit and indicating the operating state of the own unit to the lower unit. In addition, the initial value during the CPU reset and after the reset is released is set to “L” output at both the RDYup terminal and the RDYdwn terminal. As a result, after the reset is released, the signal 100 connected to the extension unit on the lower side is output.
4, 1006 and 1008 are at the “L” level.

FIG. 11 shows that the CPU 116 of each extension unit and the CPU 117 of the main unit are connected to the RDYup terminal, the RDYdwn terminal, and the TRM.
6 is a flowchart illustrating control performed on a T terminal. FIG. 12 shows a signal 1001 when this control is performed.
10 is a timing chart showing an example of a change from the step 1008 to the step 1008. The control flow of FIG. 11 will be described using this timing chart.

When the power of the apparatus is turned on and 5 V power is supplied to the CPU and the reset IC of each unit, each CPU is reset, the reset is released, and the operation of the software is started (timing). T1201). The CPU 116 of the extension unit is shown in FIG.
1 is started. When the operation starts, first, in step S1107, the RDYdwn terminal is set to the “L” level.

Next, in step S1101, the level of the TRMT terminal is checked. If the level is “L”, it is determined that no additional unit is connected to the lower side (upstream side of the transport path), and the process proceeds to S1103. Clock i in S1103
Initialize to a state where communication using signals of n, Strobe in, Data in, and Dataout (collectively referred to as Clock out etc in FIG. 10) is possible immediately. Then, RD in S1004
Set the Yup terminal to 'H'. The feeder 103 performs this processing because there is no additional unit below, and the signal 1004 changes from the “L” level to the “H” level (timing T1202).

On the other hand, when the level of the TRMT terminal is “H” level, it is determined that the extension unit is connected to the lower side, and the process proceeds to S1002. Then, RD in S1102
Wait until the Ydwn terminal becomes “H” level, that is, until the communication initialization of the lower unit is completed. For example, the feeder 102 waits in S1102 until the timing T1202 when the signal 1004 becomes the “H” level.

Then, when the RDYdwn terminal becomes "H" level, the processing of S1103 and S1104 is performed. As a result, the signal 1006 connected to the RDYup terminal of the feeder 102
Changes to the “H” level (at timing T120).
3). Similarly, when the communication initialization of the upper feeder 102 is completed and the signal 1006 changes to the “H” level, the duplex unit 106 performs the processing of S1103 and S1104, and the signal 1008 changes from the “L” level to the “H” level. (Timing T1204). And the CP of the main body
When U117 detects that the RDYdwn terminal has changed to "H" level, it starts communication with the extension unit and starts control of the extension unit. This completes the initialization of the entire device.

Thereafter, each extension unit monitors the state of the RDYup terminal (S1005). This is to monitor whether any abnormality has occurred in the upper extension unit. Here, for example, it is assumed that the upper feeder 102 has been reset by strong external noise such as ESD. Then, in the reset state, the RDYup pin and R
Both the DYdwn terminals go to the “L” level. As a result, the signals 1004 and 1006 connected to the feeder 102 become “L” level (timing T1205). When the signal 1004 becomes “L”, the RD of the lower feeder 103 is
The Yup terminal becomes “L”, and “L” in step S1005
Is detected, and the process proceeds to step S1006. This means that the feeder 103 has detected that there is some abnormality in the upper feeder 102. And feeder 103
In S1006, an operation of resetting the own unit is performed. This allows signals 1004 and 10
02 becomes the “L” level. Then, the reset of the feeder 102 that has been reset due to the noise is released, and subsequently, the reset of the feeder 103 is released. In both cases, the control of FIG. 11 is performed from the beginning.
As a result, just like after power-on reset release,
In order from the signal 1002 on the lower side of the extension unit, 100
At 4,1006, the 'L' level changes to the 'H' level.

By performing control as described above, even if an abnormality such as noise occurs in a unit, a unit affected by the operation of the unit (in the case of this embodiment,
The operation of the unit (upstream side of the transport path) can be stopped and initialized. As a result, even if the number of additional units connected to the image forming apparatus main body increases, the operation of the entire apparatus can be managed and controlled without increasing the number of additional processes of the image forming apparatus main body.

[Fourth Embodiment] FIG. 13 shows a fourth embodiment of the present invention. FIG. 13 shows the CPU of each unit.
FIG. 11 is a flowchart showing control performed on the RDYup terminal, the RDYdwn terminal, and the TRMT terminal by reference numerals 116 and 117.
The same control as in the above is assigned the same number. The control of the present embodiment differs from the control of the third embodiment in that the control of S1301 is added between the controls of S1107 and S1101. In step S1301, the apparatus is initialized as a single unit. That is, feeder 1
In steps 02 and 103, the abnormality detection and the initialization processing of the device by the feeder alone are performed. The duplex unit 106 also performs device abnormality detection and initialization processing in step S1301 using the duplex unit alone.

By controlling in this way, each additional unit or main body can be controlled without considering the contents of the initialization processing of other units and the time required for the initialization processing. Thus, even if the number of types of additional units increases, control can be performed without increasing the processing of other units.

[Fifth Embodiment] FIG. 14 is a schematic timing chart showing a fifth embodiment of the present invention, and particularly shows schematically whether communication of the CPU of each unit is active. FIG. 1 shows a system in which three expansion units are mounted on the main body 101. Now, it is assumed that, for example, a hardware reset is applied only to the extension unit 2 due to a change in power supply, and communication becomes impossible, and communication is restored after T time. If the time T during which communication was not possible is very short, for example, a time corresponding to one communication failure (referred to as T1), it is simply determined that a malfunction has occurred due to noise or the like, and the operation is continued as it is. That is, when T ≦ T1, the soft reset is not performed.

On the other hand, when the communication disabled time T is relatively long and corresponds to the time corresponding to the return from the hard reset (T2), it is determined that a considerably large electrical failure has occurred, and the system as a whole is recovered after the communication is recovered. Perform a software reset on. In other words, when an additional unit in which communication is disabled in T1 <T ≦ T2 occurs, the main body CPU 117 performs a software reset on the entire system to initialize each device. FIG. 14 shows a case where the extension unit 2 cannot communicate for a time T that satisfies T1 <T ≦ T2. After the extension units 2 return to communication, all the extension units have been soft-reset by instructions from the main unit.

Further, when the communication disabled time T is very long and greatly exceeds the time T2, it is determined that the extension unit 2 has failed, and the extension unit 2 and its upstream without the software reset are performed. The extension unit on the side (another extension unit that requires the operation of the extension unit 2 when operating according to the instruction of the main body), that is, in this embodiment, the extension unit 3 is disabled. The reason why the additional unit 3 is also disabled is that printing paper is introduced into the main body 101 via the additional unit 2.

It should be noted that the user may be notified of this state change by a printer controller or a display panel (not shown) to enhance usability.

By such control, it is possible to suspend the use of all the really necessary extension units.

[Sixth Embodiment] FIG. 15 is a schematic timing chart showing a sixth embodiment of the present invention.
This schematically shows whether the PU communication is active. This figure shows a system in which three additional units are mounted on the main body 101 as in the fifth embodiment. The print instruction is a signal output from a printer controller (not shown) to the main body CPU 117. is there.

Now, while the main unit 101 and the extension unit 1 are operating in response to a print instruction from the printer controller, communication between the suspended extension unit 2 and T1 <
It is assumed that communication is disabled within the range of T <T3. here,
T1 indicates a relatively short time during which a malfunction due to noise can be determined, and T3 indicates a time significantly exceeding the time required to return from a hardware reset.

When such a situation occurs, the main unit CP
Since U117 has occurred in the extension unit unrelated to the current job, even if the communication of the extension unit 2 is restored, the printing operation is continued immediately without performing a software reset. After receiving the end of a series of print jobs from the printer controller, the main body CPU 117 performs a software reset on all the systems to initialize each additional unit (FIG. 15).

As described above, by delaying the start of the reset processing or the use stop processing for a failure in the extension unit not related to the current job, it is not necessary to repeatedly issue a print instruction to the printer.

When the communication disabled time T of the extension unit 2 is determined to be unusable because it is longer than T3, the main unit C
The PU 117 may perform notification using a printer controller or a display panel to further improve usability. Also, as in the fifth embodiment, the necessity of the reset process may be determined with T2 as the upper limit.

[Seventh Embodiment] The operation of the seventh embodiment of the present invention will be described with reference to FIGS. 2, the output voltage (+ 5V) of the power supply 201 of the main body 101 fluctuates excessively due to factors such as external noise, and the main body 101, the duplex unit 106 connected to the main body 101, and the feeders 102, 103 When the voltage level is lower than the reset detection voltage set by the power supply voltage monitoring reset ICs 207, 208, and 209, the power supply voltage monitoring reset IC 207 outputs a reset,
The main body 101 is reset. Further, a plurality of extension units 102, 103, 10 connected to the main body 101 are provided.
6 is also supplied with power (+5) from the main body 101, so that a power supply voltage monitoring reset IC on each unit is provided.
If the ICs 208 and 209 have the same reset detection voltage as the main body 101, a reset is output as in the case of the main body 101, so that the unit is reset.

In this embodiment, as shown in FIG. 16, the reset IC 207 for monitoring the power supply voltage on the main body 101 is used.
If the reset detection voltages of the power supply voltage monitoring reset ICs 208 and 209 on the plurality of units 106, 102 and 103 connected to the main body 101 are Vb and Vc, the reset detection voltage of the main body 101 is Also lowers the detection voltage to a lower voltage level, ie, Va> Vb
> Vc.

Therefore, the power supply 102 of the main body 101
When the value of the V output drops below Va (Ta1), the reset IC 207 of the main body 101 starts operating, outputs a reset to reset the main body 101, and when the value drops below Vb (Tb1), the duplex unit 106 reset IC
When the operation starts, the duplex unit 106 is reset, and when the voltage drops below Vc (Tc1), the reset I of the upper feeder 102 and the lower feeder 103 (not shown) is reset.
C209 starts operation and resets each feeder. After that, the fluctuation of the + 5V output of the power supply 102 of the main body 101 disappears, and when returning to the normal output voltage, when the output voltage exceeds Vc (Tc2), the upper limit stage feeders 102, 103
b (Tb2), the duplex unit 106
When the value exceeds a (Ta2), the reset of the main body is released.

At this time, the reset detection voltage becomes Va>Vb>
Vc, the upper and lower feeders 103, 1
02, the duplex unit 106, and the main body 101 in this order, the respective units return to a normal state. Therefore, the main body 10
When one CPU 117 performs a communication check to grasp the current state of the system, all extension units connected to the main body 101 have already been reset and returned to a normal state. Can be correctly recognized without erroneously recognizing the additional unit.

In the present embodiment, the same reset detection voltage is set for the two feeders. However, the set value of the reset detection voltage is such that all extension units return to a normal state when the main unit returns from reset. If this is possible, not only the magnitude of the set value but also the vertical relationship of the detected voltage between adjacent extension units is arbitrary.

[Eighth Embodiment] The operation of the eighth embodiment of the present invention will be described with reference to FIGS. In the seventh embodiment, the set value of the reset detection voltage is different between the main unit and the extension unit so that all the extension units return when the main unit returns from the reset. In the present embodiment, the same effect as in the seventh embodiment can be obtained by setting the reset detection voltage common to the main unit and the extension unit, and adjusting the standby time until operation becomes possible after reset release.

That is, after the reset is released, the standby time (WA) until the main body and each extension unit can be operated again.
IT time) by the main body 101, the duplex unit 106, and the upper and lower feeders 102 and 103, respectively.
Tc.

In the present embodiment, as shown in FIG. 17, the wait time of the main body 101 is set to Ta,
Assuming that the wait time of 06 is Tb and the wait time of the upper and lower feeders 102 and 103 is Tc, Ta <Tb <
Set to be Tc. Therefore, for example, power supply 1
After the reset caused by the voltage fluctuation of 02, the fluctuation of the +5 V output of the power supply 102 of the main body 101 disappears, and the order in which the respective units return to the normal state is determined by the feeder 103.
(102), the duplex unit 106 and the main body 101 are formed.

Therefore, when the CPU 117 of the main body 101 performs a communication check to grasp the current system state, all the extension units connected to the main body 101 have already returned to the normal state. It becomes possible to correctly recognize the added extension unit without erroneous recognition.

In the present embodiment, the same wait time Tc is set for the two feeders. However, the set value of the wait time is such that when the main unit returns from reset, all the extension units return to a normal state. If possible, not only the magnitude of the set value but also the vertical relationship of the WAIT time between adjacent extension units is arbitrary.

[Other Embodiments] The present invention can be applied to any device or system having a main body and an extension unit that can communicate with each other. Also, in the present invention, the configuration of each unit is arbitrary as long as the main unit can control each extension unit and can monitor the state, and for example, a configuration without using a CPU may be used. Further, although the power supply voltage is used as a condition for resetting, any other signal may be used as long as it is a signal that is supplied to all units and has a certain level at normal time.

Further, an object of the present invention is to supply a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or CPU) of the system or the apparatus.
And MPU) read and execute the program code stored in the storage medium. In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention. Examples of the storage medium for supplying the program code include a floppy disk, hard disk, optical disk, magneto-optical disk, and C
A D-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, and the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments. Further, after the program code read from the storage medium is written into a memory provided on a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that a CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0087]

As described above, according to the present invention,
Even if a communication error such as a parity error occurs due to various factors such as external noise, it becomes possible to return control of each unit to normal.

Further, by changing the number of continuous occurrences of the communication abnormality determined as the unit abnormality depending on the type of the unit, it is possible to detect the abnormality appropriately in accordance with the characteristics of the unit.

Further, even when a plurality of extension units connected to the main unit are reset due to fluctuations in the power supply voltage due to various factors such as external noise, the extension units always return to the operable state first. Therefore, when the main unit returns to the operable state and performs a communication check or the like in order to grasp the current state of the system, it is possible to correctly recognize the type and connection state of the connected unit.

[0090]

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a printer system according to an embodiment of the invention.

FIG. 2 is a block diagram illustrating a configuration of a printer according to the embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of a CPU according to the embodiment of the present invention.

FIG. 4 is a timing chart illustrating inter-unit communication according to the embodiment of the present invention.

FIG. 5 is a flowchart illustrating control of communication between units according to the embodiment of the present invention.

FIG. 6 is a flowchart illustrating control of communication between units according to the embodiment of the present invention.

FIG. 7 is a diagram illustrating an abnormality detection method according to the first embodiment of the present invention.

FIG. 8 is a diagram illustrating an abnormality detection method according to the first embodiment of the present invention.

FIG. 9 is a flowchart illustrating control of inter-unit communication according to the second embodiment of the present invention.

FIG. 10 is a block diagram illustrating a configuration of a printer according to a third embodiment of the invention.

FIG. 11 is a flowchart illustrating control of a CPU according to a third embodiment of the present invention.

FIG. 12 is a timing chart illustrating control of a CPU according to a third embodiment of the present invention.

FIG. 13 is a flowchart illustrating control of a CPU according to a fourth embodiment of the present invention.

FIG. 14 is a timing chart illustrating control of a CPU according to a fifth embodiment of the present invention.

FIG. 15 is a timing chart illustrating control of a CPU according to a sixth embodiment of the present invention.

FIG. 16 is a timing chart of a printer according to a seventh embodiment of the invention.

FIG. 17 is a timing chart of the printer according to the eighth embodiment of the invention.

[Explanation of symbols]

 Reference Signs List 101 Printer main body 102 Upper feeder 103 Lower feeder 106 Double-sided unit 116 CPU in extension unit 117 Main body CPU 118, 119, 120 Cable for communication between units 201 Main power supply 207, 208, 209 Reset IC

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06F 13/00 301 H04N 1/00 106C H04N 1/00 106 B41J 29/00 B (72) Inventor Akihiro Shibata 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) in Canon Inc. EE00 GG01 5C062 AA01 AA05 AB38 AC21 AC35 AC38 AC55 AC58 AE13 AF06 BA04

Claims (19)

[Claims] 1. An apparatus comprising: a main unit having communication means; and at least one additional unit connected to the main unit and capable of communicating with the main unit, wherein the main unit is connected to the additional unit. A device comprising a plurality of units, wherein the normality / abnormality of the extension unit is determined by the communication of (1) and the criteria for the determination are changed according to the type of the extension unit. 2. An apparatus comprising: a main unit having communication means; and at least one additional unit connected to the main unit and capable of communicating with the main unit, wherein the main unit is connected to the additional unit. A device comprising a plurality of units, wherein the normality / abnormality of the extension unit is determined by the communication of (1), and the reference for the determination is changed according to the state of the main unit. 3. An apparatus comprising a main unit and at least one additional unit connected to the main unit, wherein the main unit is connected to the additional unit when initializing the entire apparatus. An apparatus comprising a plurality of units, each of which performs its own initialization after finishing its initialization. 4. An apparatus comprising: a main unit having communication means; and at least one additional unit connected to the main unit and capable of communicating with the main unit, wherein the main unit is periodically connected to the main unit. An apparatus comprising a plurality of units, which communicates with all of the extension units and, when there is an extension unit in a communication disabled state, determines whether or not to perform a return process according to the duration of the communication disabled state. . 5. The method according to claim 4, wherein the return processing is divided into a return processing for only the additional unit and a return processing for all units, and one of the return processing is selected according to the duration of the communication disabled state. An apparatus comprising a plurality of units as described. 6. An apparatus comprising a plurality of units according to claim 1, wherein said communication is performed by a loop communication path connected to all of said main unit and said extension unit. . 7. An apparatus comprising: a main unit; and a plurality of extension units connected to the main unit for increasing the function of the main unit, wherein the main unit and the plurality of extension units are connected to each other. If a suspended extension unit fails while a part is being processed,
An apparatus comprising a plurality of units, wherein a recovery process of the extension unit in which the abnormality has occurred is performed after the process is completed. 8. An apparatus comprising a main unit and at least one additional unit connected to the main unit, wherein the main unit supplies a signal of a constant level to all of the additional units. A supply unit, and a first initialization unit that monitors an output signal level of the signal supply unit and initializes the main unit when the output signal level becomes equal to or lower than a first level. Monitoring the output signal level of the signal supply means, and initializing the extension unit when the output signal level falls below a second level lower than the first level.
An apparatus comprising a plurality of units, comprising: 9. When there are a plurality of extension units, at least one of the first and second extension units is included in the plurality of extension units.
9. An extension unit having initialization means for initializing a corresponding extension unit at a third level lower than the second level and different from the second level and lower than the third level is included. Device consisting of multiple units. 10. When the number of the extension units is plural,
The first-stage initialization means of the extension unit directly connected to the main unit is lower than the first-stage first level, and has the same or higher level as the first-stage initialization means of the other first-stage extension units. 9. The apparatus comprising a plurality of units according to claim 8, wherein the level is a level. 11. An apparatus comprising a main unit and at least one additional unit connected to the main unit, wherein the main unit supplies a signal of a constant level to all of the additional units. Supply means, first output means for monitoring the output signal level of the signal supply means, and initializing the main unit when the output signal level reaches a predetermined level; and returning to normal operation after completion of the initialization. A first timer unit that waits for a first time until the extension unit monitors an output signal level of the signal supply unit and initializes the extension unit corresponding to the predetermined level. Second initialization means, and second timer means for, after initialization, waiting for a second time shorter than the first time until returning to a normal operation. Apparatus comprising a plurality of units to symptoms. 12. When the number of the extension units is plural,
At least one of the plurality of extension units includes an extension unit having timer means for waiting for an extension unit shorter than the first time and corresponding to a third time different from the second time. An apparatus comprising a plurality of units according to claim 11, characterized in that: 13. When there are a plurality of said extension units,
The standby time of the first timer unit of the extension unit directly connected to the main unit is shorter than the first time of the first period, and is equal to or longer than the standby time of the first timer unit of the other first unit. An apparatus comprising a plurality of units according to claim 11, which is long. 14. An abnormality detection method for an apparatus comprising: a main unit having communication means; and at least one additional unit connected to the main unit and capable of communicating with the main unit. An abnormality detection method for an apparatus comprising a plurality of units, comprising determining whether the extension unit is normal or abnormal by communicating with the extension unit, and changing a criterion for the determination depending on the type of the extension unit. 15. An abnormality detection method for an apparatus comprising: a main unit having communication means; and at least one additional unit connected to the main unit and capable of communicating with the main unit. An abnormality detection method for an apparatus comprising a plurality of units, wherein the normality / abnormality of the extension unit is determined by communication with the extension unit, and the reference for the determination is changed according to the state of the main unit. 16. An initialization method in an apparatus including a main unit and at least one additional unit connected to the main unit, wherein the main unit is connected when initializing the entire apparatus. A method of initializing an apparatus comprising a plurality of units, wherein all of the expansion units perform their own initialization after finishing the initialization. 17. An initialization method in an apparatus comprising a main unit having communication means and at least one additional unit connected to the main unit and capable of communicating with the main unit, wherein the main unit is The communication unit periodically communicates with all of the extension units, and when there is an extension unit in a communication disabled state, it is determined whether or not to perform initialization processing according to the duration of the communication disabled state. A method for initializing a multi-unit device. 18. The initialization process is divided into an initialization process for only the relevant additional unit and an initialization process for all units, and selects one according to the duration of the communication disabled state. The method for initializing a device comprising a plurality of units according to claim 17. 19. A method for initializing an apparatus comprising a main unit and a plurality of extension units connected to the main unit to increase the function of the main unit, the method comprising: A part of the additional unit is being processed, and if the suspended additional unit is abnormal, the processing is terminated and then the abnormally expanded unit is initialized. A method for initializing a device comprising: