JP2006154247A - Extension interface device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the frequency of communication for monitoring a state of an entire device without increasing the number of signal lines in an extension unit interface. <P>SOLUTION: An extension interface device is constituted in such a way that common communication signal lines connecting the device main body and respective extension units in parallel are used, a part of communication data is used as a status of state changes by each extension unit, and the plurality of extension units whose states have changed can be simultaneously return the statuses, thereby the device main body can monitor state changes of all extension units by status reception. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid increasing interface device used when a plurality of optional devices are added to an apparatus main body.

In a conventional extension unit interface device, multiple extension units are connected to the main unit in a sequential bus so that the predetermined processing from the main unit can be recognized at the same time, and each extension unit operates according to the process. (For example, refer to Patent Document 1). In addition, there is one provided with an in-flight communication interface provided with means for notifying a higher-level device of a change in internal state in a lower-level device (for example, see Patent Document 2).
Japanese Patent Laid-Open No. 08-008935 Japanese Patent Laid-Open No. 02-333028

  However, in the above conventional example, although the number of communications related to commands from the device main body can be reduced, when monitoring the status change in the extension unit, the device main body indicates status data indicating the status to each extension unit. Because it was necessary to send a command requesting status and receive status data separately from each expansion unit, the number of communications to monitor the status of the entire device increases, and the communication load increases as the number of expansion unit connections increases. There was a disadvantage that increased.

  Also, as in Patent Document 2, when providing a signal for notifying the internal state of the apparatus, a signal line is necessary for the notification, and after the apparatus body knows the internal change, In order to identify the changed extension unit, a command for requesting status data has to be sent sequentially, and the status of the entire apparatus cannot be confirmed unless status data is received for all the extension units.

  An object of the invention according to the present application is to reduce the number of communications for monitoring the state of the entire apparatus without increasing the number of signal lines for communication in the extension unit interface apparatus.

In order to achieve the above object, the invention according to the present application includes a communication unit that connects the apparatus main body and each of the plurality of extension units in parallel, a monitoring unit that monitors a state in the extension unit,
One of detection means for detecting that the internal state of the extension unit has been changed by the monitoring means, analysis means for analyzing the information transmitted from the apparatus main body by the communication means, and one piece of information sent from the extension unit to the apparatus main body by the analysis means It is characterized in that there is provided an informing means for determining whether the part can be shared as the output of the detecting means, and in the case where the sharing is possible, the internal state change of the extension unit is part of the information sent to the apparatus main body.

  As described above, according to the present invention, a common communication signal line connected in parallel between the apparatus main body and each extension unit is used, and a part of the communication is simultaneously used by each extension unit as a status change status. As a result, it is possible to simultaneously specify a plurality of extension units having a change in state, thereby reducing unnecessary communication.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  FIG. 1 is a drawing that best represents the features of the present invention. In FIG. 1, reference numeral 1 denotes a printer body, 2 denotes a CPU that controls the operation of the printer body 1, an output signal line 3 for driving various motors, various sensors, and the like. It incorporates an input signal line 4 for inputting signals, a ROM for storing control programs and data, and a RAM for calculation and the like. // CS signal line is a select signal for serial communication and indicates that communication is in progress at L level. The SCLK signal line is a clock signal for serial communication, and transmits data at the falling edge of the SCLK signal and receives data at the rising edge. The CMD signal line is a command signal for transmitting various command data from the printer main body 1 to the optional paper feeder 6.

  The STS signal line is a status signal for returning various information data from the optional paper feeding device 6 to the printer main body 1 and a signal representing a state change of the optional paper feeding device 6 described later. 5 is a resistor that pulls up the STS signal, 6a, 6b, 6c, and 6d are optional sheet feeding devices connected to the printer body 1, and 7a, 7b, 7c, and 7d are CPUs that control the operation of the optional sheet feeding device. An output signal line 8 for driving a motor, a solenoid and the like, an input signal line 9 for inputting signals from various sensors, a ROM for storing a control program and data, and a RAM for calculation and the like are incorporated. 10a, 10b, 10c, and 10d are transistors connected to the STS signal line through an open collector connection. When the STSn signal (n = 1, 2, 3, 4) connected to the base is at the H level, the STS signal line is set at the L level. When the STSn signal is at L level, the STS signal line is opened (H level because it is pulled up by the resistor 5). Reference numerals 11 a, 11 b, 11 c, and 11 d are resistors connected to the base of the transistor 10.

  FIG. 2 is a cross-sectional view of the printer of the present invention. In FIG. 2, reference numeral 12 denotes a photosensitive drum whose surface can move endlessly, 13 a charger for uniformly charging the surface of the photosensitive drum 12, and 14 a photosensitive drum. Laser light emitting means for scanning the body drum 12, 15 a developing device for converting an electrostatic latent image into a toner image, 16 a paper feed tray, and 17 a paper feed roller for feeding and transporting paper set in the paper feed tray 16 And 18, a paper feed sensor 19 for detecting the presence or absence of the fed paper temporarily stops the fed paper, eliminates the skew of the paper, and synchronizes the toner image on the photosensitive drum 12 and the paper conveyance. The registration roller 20 is a transfer charger for transferring a toner image onto paper, and 21 is a fixing device for fixing a toner image on paper, which is removable from the main body. 22 is a paper discharge sensor that detects the presence or absence of paper discharged from the fixing device 20, 23 is a paper discharge tray, 24a, 24b, 24c, and 24d are paper feed cassettes built in the optional paper feeder 6, 25a, 25b, 25c and 25d are paper feed rollers that feed and transport the paper set in the paper feed cassette 24, 26a, 26b, 26c, and 26d are transport rollers that transport the paper, and 27a, 27b, 27c, and 27d are the transported paper. It is a conveyance sensor which detects the presence or absence.

Next, the printing operation of the laser beam printer according to this embodiment will be described.
When the power is turned on, the CPU 2 drives the heat source in the fixing device 21 and raises the temperature until the temperature of the fixing device 21 reaches the standby temperature. Also, it is checked whether or not paper is loaded in the paper feed cassette 24, whether or not image formation (hereinafter referred to as printing) is possible, and when the print is ready, the charger 13 and the transfer charger 20 are turned on. In this state, the surface potential of the photosensitive drum 12 is initialized.

  At this time, the rotation of the horizon mirror is also started, and the CPU 2 controls the heat source to raise the temperature of the fixing device 21 to the fixing required temperature. Then, when the rotation of the polygon mirror is stabilized and the temperature of the fixing device 21 reaches a feed permission temperature, that is, a temperature that can become the necessary fixing temperature within the time when the fed paper reaches the fixing device 21, The paper is transported from the paper cassette 24 by the paper feed roller 25 and the transport roller 26 until it reaches the registration roller 19.

  When the leading edge of the paper reaches the registration roller 19, the conveyance of the paper is once stopped, and the paper feeding from the registration roller 19 is resumed. At the same time, the laser emission means 14 is statically placed on the photosensitive drum 12 according to the image signal. An electrostatic latent image is formed. The electrostatic latent image is developed into a toner image by the developing device 15, and transferred to the fed paper by the transfer charger 20. The paper on which the toner image has been transferred reaches the fixing device 21.

At this time, the temperature in the fixing device 21 is a fixing required temperature, and the toner image is sufficiently fixed on the paper by heating and pressurizing while holding and conveying the paper.
In the fixing operation, after the image formation for one page is completed and the surface potential of the photosensitive drum 12 is made uniform by the charger 13 for the next image formation, the paper is discharged to the discharge tray 23. Thus, the process is terminated when the next printing operation is not generated during this process, and the temperature of the fixing device 21 is controlled at the standby temperature in order to avoid excessive temperature rise.

  After the fixing operation is completed, for example, about 10 seconds, the process of making the surface potential of the photosensitive drum 12 uniform is continued so that the next image can be formed immediately. At this time, the transfer charger 20 and the charger 13 are sequentially turned off to stop the rotation of the photosensitive drum 12 (this process is referred to as post-rotation processing).

  When the post-rotation processing is completed, a series of printing operations is completed, and thereafter, the standby state is entered.

  FIG. 3 is a list of commands in serial communication for giving an instruction from the printer main body 1 of the present invention to the optional sheet feeding device 6 and shows correspondence between 10 types of commands, a return status, and a command code.

  In the figure, a basic status request command is a command for requesting the return of a basic status as a return status from an optional sheet feeding device 6 specified by an ID described later, and a state change status request command is returned from an option sheet feeding device 6 specified by an ID. A command requesting the return of the status change status as the status, the detailed 1 status request command is a command requesting the return of the detailed 1 status as the return status from the optional sheet feeding device 6 specified by the ID, and the detailed 2 status request command is specified by the ID The command for requesting the return of the detailed 2 status as the return status from the option sheet feeding device 6 and the motor drive command are commands for instructing the option sheet feeding device 6 designated by the ID to start the motor, and the basic status is returned. . The motor stop command is a command for instructing the optional sheet feeding device 6 specified by the ID to stop the motor, and a basic status is returned.

  The paper feed start command drives a paper feed drive solenoid (not shown) for a predetermined time with respect to the optional paper feed device 6 designated by the ID and rotates the paper feed roller 25 once to feed the paper from the paper feed cassette 24 to the transport roller 26. The basic status is returned by the command to feed paper. The conveyance start command is a command for driving a conveyance drive solenoid (not shown) to the optional sheet feeding device 6 designated by the ID and rotating the conveyance roller 26, and the basic status is returned. The transport stop command is a command for stopping driving of a transport driving solenoid (not shown) and stopping the transport roller 26 with respect to the optional sheet feeding device 6 specified by the ID, and a basic status is returned. The reset command is a command for instructing the optional sheet feeding device 6 designated by the ID to be in an initial state, and a basic status is returned.

FIG. 4 shows the correspondence between the ID and the optional paper feeder 6.
In the figure, when [ID1, ID0] = [0, 0], the optional sheet feeder 6a, and when [ID1, ID0] = [0, 1], the optional sheet feeder 6b, [ID1, ID0] = When [1, 0], the optional paper feeder 6c, and when [ID1, ID0] = [1, 1], the optional paper feeder 6d.

  FIG. 5 is a diagram showing the configuration of commands and statuses. In FIG. 5, the command configuration is such that 1st bit is 0, 2nd-3rd bit is an ID for identifying the optional sheet feeder 6, and 4th-7th bit is the type of command. Odd parity bits are added to 8th bit so that the number of all 1s is odd.

  The basic status configuration is 1st bit and 3rd bit set to 0, 2nd bit is set to 1 when there is an error in communication, 4th bit is the status change bit of the optional paper feeder 6d, 5th bit is supplied as option The status change bit of the paper device 6c, the 6th bit is the status change bit of the optional paper supply device 6b, the 7th bit is the status change bit of the optional paper supply device 6a, and the odd parity so that all 1's are odd numbers in the 8th bit. Add a bit. The status change bit is set to 0 when there is a change in the internal state of the optional sheet feeding device 6. When the basic status is returned from any one optional sheet feeding device 6, there is a change in the state. It is also assumed that the other optional paper feeders send out in accordance with the arrangement timing of the basic status configuration. (Refer to the timing chart of FIG. 7.) The state change status configuration is such that 1st bit and 3rd-5th bit are 0, 2nd bit is an error bit that is set to 1 when there is an error in communication, and 6th bit is the state of various sensors. A bit indicating that there has been a change, 7th bit indicating that there has been a change in the paper size state, and odd parity bits are added to the 8th bit so that all the numbers of 1 are odd.

  Detailed 1 status configuration: 1st bit and 3rd bit are 0, 2nd bit is an error bit that is set to 1 when there is an error in communication, 4th-7th bit is paper size detected by output of paper size detection switch (not shown) Odd parity bits are added so that the number of all 1s is odd in the 8th bit.

  Detail 2 status configuration, 1st bit and 3rd-4th bit are 0, 2nd bit is an error bit that is set to 1 when there is an error in communication, 5th bit is a bit that indicates the presence or absence of paper in the transport sensor 27, 6th bit is a bit indicating the presence / absence of the paper feed cassette 24 of the cassette presence / absence detection sensor (not shown), 7th bit is a bit indicating the paper presence / absence status of the paper presence / absence sensor for detecting the presence of paper in the paper feed cassette 24 (not shown), 8th Odd parity bits are added so that all 1's numbers are odd.

  FIG. 6 is a flowchart showing a part of the state detection control of the printer main body 1 according to the present invention. In FIG. 6, step S101 sets the // CS signal to L level in order to transmit a command. In step S102, an SCLK signal for 8 clocks is sent, and data conforming to the above-described command configuration is sent to the CMD signal. In step S103, the option paper feeder 6 waits for a predetermined time to adjust the time for preparing the status data. In step S104, an SCLK signal for 8 clocks is sent to receive the status, and data is received from the STS signal in synchronization with the rising edge of the SCLK signal.

  In step S105, because one communication is completed, the // CS signal is set to the H level. In step S106, it is confirmed whether or not the 2nd bit of the received status data is set to 1. If it is set to 1, an error has occurred in communication, and the process returns to step S101 without performing further processing. In step S107, when it is determined that the return status for the transmitted command is not the basic status, the processing after detecting the state change is not performed, and other status processing is performed, and the process returns to step S101.

  In step S108, it is determined whether any of the 4th-7th bits of the received basic status data is 0. If all the bits are 1, it is determined that there is no state change in the optional paper feeder 6 and the flow advances to step S101. Return. In step S109, the status change bit of the basic status identifies the option sheet feeder 6 that has changed state, and the identified option sheet feeder 6 recognizes the status changed by a status request command other than the basic status. The process is performed and the process returns to step S101.

  FIG. 7 is a flowchart showing a part of the state change notification control of the optional sheet feeder 6 of the present invention. In FIG. 7, step S201 indicates that the // CS signal becomes L level in order to receive a command. If it is determined that the // CS signal becomes L level, the process proceeds to step S202. In step S202, command data is received from the CMD signal in synchronization with the rising edge of the SCLK signal for 8 clocks.

  In step S203, it is determined whether the ID of the command data designates the own unit. If the own unit is designated, the process proceeds to step S204, and if another unit is designated, the process proceeds to step S211. In step S204, it is determined whether the received command is a status request command (command codes 0 to 3). If the command is a status request command, the process proceeds to step S208, and if it is any other command, the process proceeds to step S205. In step S205, it is determined whether or not the received command is an execution command (command codes 4 to 9). If it is an execution command, the process proceeds to step S209. Otherwise, the process proceeds to step S206. A step S206 prepares a return status in which the error bit is set to 1 because there is an error in the received command. In step S207, a return status is sent to the STS signal in synchronization with the rising edge of the SCLK signal for 8 clocks. In step S208, the requested status is prepared as a return status. In step S209, the operation according to the execution command is started.

  In step S210, a basic status is prepared as a return status of the execution command. In step S211, it is determined whether or not the status of the own unit has changed since the last return of the basic status. If the status has changed, the process proceeds to step S212. In step S212, the SCLK signal sent from the printer main body 1 for the return status from the other unit is counted. If the count value is 8-the option number of the own unit, the process proceeds to step S214. Otherwise, step S213 is executed. Move on. In step S213, the STSn signal (n is the option number of its own unit) is set to L level, and the STS signal is released. In step S214, the STSn signal (n is an option number of the own unit) is set to the h level, and the STS signal is set to the L level to notify the printer main body 1 of the state change. In step S215, it is determined whether the count value of the SCLK signal has reached 8, and the process returns to step S212 until it reaches 8.

  FIG. 8 is a timing chart of serial communication. The // CS signal is set to L level from the printer main body 1 and the SCLK signal is sent for 8 clocks, and command data is sent to the CMD signal in synchronization with the falling edge of the SCLK signal. Then, the return status data is sent from the option paper feeder 6 to the STS signal in synchronization with the falling edge of the next 8 SCLK signals.

  As described above, using a common serial communication signal line that connects the printer main unit and the optional paper feeder in parallel, a part of the basic status data is simultaneously used by each optional paper feeder as the status change status. As a result, it is possible to simultaneously specify a plurality of extension units having a change in state, thereby reducing unnecessary communication.

  Another embodiment of the present invention will be described with reference to FIG. 9 of the accompanying drawings.

  The configuration of the second embodiment is the same as that of the printer main body 1 of the first embodiment except for the portions described below, and the same functions are denoted by the same reference numerals and detailed description thereof is omitted.

  In FIG. 9, the AD0 signal line, AD1 signal line, AD2 signal line, and AD3 signal line are bidirectional data buses, and output and input status data ports from the command data ports C0, C1, C2, and C3 of the CPU 2 of the printer body 1. S0, S1, S2. Connected to S3. The / CE signal is a signal indicating the data switching timing of the bus communication command and status, and the data bus (AD0, AD1, AD2, AD3) is a command when the / CE signal is at L level and a status when at the H level. 28 is a resistor pulling up the AD signal, 29 is a resistor pulling up the AD3 signal, 30 is a resistor pulling up the AD3 signal, 31 is a resistor pulling up the AD3 signal, 32 is When the / CE signal is at the L level in the bidirectional buffer, the C0 signal is output to the AD0 signal line, and when the / CE signal is at the H level, the AD0 signal is input to the S0 signal.

Reference numeral 33 denotes a bidirectional buffer. When the / CE signal is at L level, the C1 signal is output to the AD1 signal line, and when the / CE signal is at H level, the AD1 signal is input to the S1 signal.
A bidirectional buffer 34 outputs the C2 signal to the AD2 signal line when the / CE signal is at the L level, and the AD2 signal is input to the S2 signal when the / CE signal is at the H level.

  A bidirectional buffer 35 outputs the C3 signal to the AD3 signal line when the / CE signal is at the L level, and the AD3 signal is input to the S3 signal when the / CE signal is at the H level.

  36a, 36b, 36c and 36d are bidirectional buffers. When the / CE signal is at L level, the CPU 7 sets the Sn0 signal to L level so that the Sn0 signal (n = 1, 2, 3, 4) is not output to the AD0 signal line. When the AD0 signal is input to the Cn0 signal (n = 1, 2, 3, 4), and the / CE signal is at the H level and it is desired to output 0 as the status data, the Sn0 signal (n = 1, 2, , 3, 4) is set to H level, L level is output to the AD0 signal, and 1 is output as status data, the Sn0 signal (n = 1, 2, 3, 4) is set to L level, and the AD0 signal is output. It is opened (the output of the bidirectional buffer becomes high impedance) and becomes H level by the pull-up resistor 31.

  37a, 37b, 37c, and 37d are bidirectional buffers. When the / CE signal is at L level, the CPU 7 sets the Sn1 signal to L level so that the Sn1 signal (n = 1, 2, 3, 4) is not output to the AD1 signal line. When the AD1 signal is input to the Cn1 signal (n = 1, 2, 3, 4) and the / CE signal is at the H level and 0 is to be output as the status data, the Sn1 signal (n = 1, 2, , 3, 4) are set to H level, L level is output to the AD1 signal, and 1 is output as status data, the Sn1 signal (n = 1, 2, 3, 4) is set to L level, and the AD1 signal is Opened (the output of the bidirectional buffer becomes high impedance) and becomes H level by the pull-up resistor 30.

  38a, 38b, 38c, and 38d are bidirectional buffers. When the / CE signal is at L level, the CPU 7 sets the Sn2 signal to L level so that the Sn2 signal (n = 1, 2, 3, 4) is not output to the AD2 signal line. When the AD2 signal is input to the Cn2 signal (n = 1, 2, 3, 4) and the / CE signal is at the H level and 0 is to be output as the status data, the Sn2 signal (n = 1, 2, , 3, 4) is set to H level, L level is output to the AD2 signal, and 1 is output as status data, the Sn2 signal (n = 1, 2, 3, 4) is set to L level, and the AD2 signal is It is opened (the output of the bidirectional buffer becomes high impedance) and becomes H level by the pull-up resistor 29.

  39a, 39b, 39c, and 39d are bidirectional buffers. When the / CE signal is at L level, the CPU 7 sets the Sn3 signal to L level so that the Sn3 signal (n = 1, 2, 3, 4) is not output to the AD3 signal line. When the AD3 signal is input to the Cn3 signal (n = 1, 2, 3, 4) and the / CE signal is at the H level and 0 is to be output as status data, the Sn3 signal (n = 1, 2, , 3, 4) is set to the H level, the L level is output to the AD3 signal, and 1 is output as the status data, the Sn3 signal (n = 1, 2, 3, 4) is set to the L level and the AD3 signal is output. Opened (the output of the bidirectional buffer becomes high impedance) and becomes H level by the pull-up resistor 28.

  FIG. 10 is a list of commands in the bus communication for giving an instruction from the printer main body 1 to the optional sheet feeding device 6 according to the present invention, and describes correspondence between 14 types of commands, return statuses, and command codes.

  In the figure, the option 1 designation command is directed to the option sheet feeding device 6a as a command to be transmitted thereafter. In the option 2 designation command, the target of the command to be transmitted thereafter is the option sheet feeding device 6b. In the option 3 designation command, the target of the command transmitted thereafter is the option sheet feeding device 6c. In the option 4 designation command, the target of the command to be transmitted thereafter is the option sheet feeding device 6d. Note that the option x designation command (x = 1, 2, 3, 4) is valid until another option x designation command is sent next time.

  Regarding the other commands, operations other than the designation of the ID changed to the option x designation command are the same as those of the printer main body 1 of the first embodiment, and detailed description thereof will be omitted.

  FIG. 11 is a diagram showing a status configuration. In FIG. 11, the basic status is that S3 is a change in the state of the option sheet feeding device 6d, S2 is a state change in the option sheet feeding device 6c, and S1 is an option sheet feeding device 6b. The status change, S0, is received from the data bus (AD0, AD1, AD2, AD3). As shown in the flowchart of FIG. 14, each optional sheet feeding device 6 sets the bit corresponding to the above to 0 if the internal state changes in the basic status transmission state.

The status change status, detailed 1 status, and detailed 2 status bits are the same as those of the printer main body 1 of the first embodiment, and detailed description thereof is omitted.
FIG. 12 is a timing chart of bus communication. The printer body 1 sets the / CE signal to L level and sends command data (C0, C1, C2, C3) to the data bus (AD0, AD1, AD2, AD3). The CE signal is set to H level and status data (S0, S1, S2, S3) is received from the data bus (AD0, AD1, AD2, AD3).

  FIG. 13 is a flowchart showing a part of the state detection control of the printer main body 1 according to the present invention. In FIG. 13, step S301 sets the / CE signal to L level in order to transmit a command. In step S302, a basic status request command (C0 = 0, C1 = 0, C2 = 0, C3 = 0) is sent to the data bus (AD0, AD1, AD2, AD3). In step S303, the / CE signal is set to the H level in order to receive the status. In step S304, the basic status data (S0, S1, S2, S3) are monitored, and if the status data are all 1, the process proceeds to step S306, assuming that there is no state change, and if any bit is 0, there is a state change. If not, the process proceeds to step S305. Step S305 returns to step S301 after executing other command processing of the optional sheet feeding device 6 whose state has changed from the bit that has become 0 of the basic status data (S0, S1, S2, S3), and other command processing is performed. If not necessary, the process returns to step S304 to recognize the state, and determines processing according to the state change. In step S306, it is determined whether other command processing is necessary. If other command processing is necessary, change monitoring is continued.

  FIG. 14 is a flowchart showing a part of the state change notification control of the optional sheet feeder 6 in the present invention. In FIG. 14, step S401 determines whether the / CE signal is at L level. As reception, the process proceeds to step S403. In step S402, it is determined whether the current return status is the basic status. If the status is not the basic status, the process proceeds to step S407. Since the state change cannot be sent to the data buses (AD0, AD1, AD2, AD3) in step S403, the Smn signal (m: option number, n = 1, 2, 3, 4) is set to L level to release the data bus. . Step S404 receives command data. In step S405, it is determined whether the internal state has changed. If there is a change, the process proceeds to step S406, and if there is no change, the process proceeds to step S407.

  In step S406, since the internal state has changed, the Sm (m-1) signal (m: option number, eg, S21 for option number 2) is set to H level, and the data bus AD (m-1) is set to L level. As a result, the printer 1 is notified of the state change. In step S407, since the internal state does not change, the Sm (m-1) signal (m: option number, for example, S32 in the case of option number 3) is set to L level, and the data bus AD (m-1) is released.

  As described above, the basic status data can be used as the status change status of each optional paper feeder using a common bus signal line that connects the printer body and the optional paper feeder in parallel. Since the printer main body 1 can arbitrarily set the data output period of the basic status by bus communication, the state change can be recognized more easily.

  Although the embodiment using the clock synchronous serial communication in the first embodiment and the bus communication in the second embodiment has been described, the present invention is not limited to these communication schemes, and a plurality of units can share a common communication signal. As long as the communication mode is such that the communication timing can be defined by connecting with the above, the same thing as the embodiment can be realized regardless of the data width or the like.

It is a figure explaining the control block which concerns on 1st Example of this invention. 1 is a diagram illustrating a cross section of a printer according to a first embodiment of the invention. FIG. It is a figure explaining the command system which concerns on 1st Example of this invention. It is a figure explaining the option number which concerns on 1st Example of this invention. It is a figure explaining the command status structure which concerns on 1st Example of this invention. It is a figure explaining the printer control which concerns on 1st Example of this invention. It is a figure explaining option control concerning the 1st example of the present invention. It is a figure explaining the timing of the serial communication which concerns on 1st Example of this invention. It is a figure explaining the control block concerning the 2nd example of the present invention. It is a figure explaining the command structure concerning the 2nd example of the present invention. It is a figure explaining the status structure which concerns on 2nd Example of this invention. It is a figure explaining the timing of the communication which concerns on 2nd Example of this invention. It is a figure explaining printer control concerning the 2nd example of the present invention. It is a figure explaining option control concerning the 2nd example of the present invention.

Explanation of symbols

1 Printer body 2 CPU
6 Optional paper feeder 7 CPU

Claims (1)

In an expansion interface device that connects multiple expansion units to the device body,
A communication means for connecting the apparatus body and each of the plurality of extension units in parallel;
Monitoring means for monitoring the status in the expansion unit;
Detecting means for detecting that the internal state of the extension unit has been changed by the monitoring means;
Analysis means for analyzing information transmitted from the apparatus main body by communication means;
The analysis means determines whether a part of the information sent from the extension unit to the device main body can be shared as the output of the detection means, and if it can be shared, the internal status change of the extension unit is sent to the device main body Notification means for
An extension interface device characterized by the provision of

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