JP6677026B2 - Communication apparatus, signal voltage amplitude level control method, and program - Google Patents

Description

  The present invention relates to a communication device, a signal voltage amplitude level control method, and a program.

  2. Description of the Related Art Conventionally, USB (Universal Serial Bus) has been used in a wide field as one of communication standards for connecting a host device and an external device (peripheral device or the like). Generally, as the signal transmission path becomes longer, the resistance component and the capacitance component increase. The voltage amplitude level of the transmission signal transmitted through the signal transmission path is attenuated by the resistance component and the capacitance component, and the signal tends to be distorted toward the receiving side and the eye pattern is crushed. Therefore, the USB standard defines the voltage amplitude level of the signal on the transmission side, the length and the impedance characteristics of the USB cable used for the signal transmission path, and ensures the signal quality on the reception side.

  As an invention for performing signal transmission without distortion, there is disclosed an invention in which the output impedance of a drive current control circuit on the transmission side is matched with the impedance of a USB cable. According to the invention, the transmission side outputs the test pattern signal to the reception side, and the reception side determines the reception level of the signal voltage of the signal. The transmitting side receives the instruction signal indicated by the determination result from the receiving side, thereby controlling the driving current to match the impedance. This suppresses a reduction in signal voltage due to reflection (see Patent Document 1).

  However, in a device such as a multifunction peripheral equipped with a USB, the size of the main body, the device configuration, and the like change according to the paper size, printing speed, and the like. In such a device, the output terminal of the USB host controller and the output terminal of a device such as a general-purpose USB connector to which a general-purpose USB device is connected are relatively separated due to physical configuration restrictions. For this reason, these connections in the machine are performed by a relay cable, a connector, or the like. In such a device, the signal transmission path in the device is relatively long, so that both the voltage amplitude level of the transmission signal at the output end of the USB host controller and the output end of the device need to satisfy the USB standard. However, there is a suitable configuration of the signal transmission path in the device according to the type of device, and if the configuration changes, for example, the length of the relay cable changes, the desired signal quality cannot be obtained on the receiving side, and the communication quality deteriorates. There was a problem of doing.

  The present invention has been made in view of the above, and provides a communication device, a control method of a signal voltage amplitude level, and a program for suppressing a decrease in communication quality due to a difference in the configuration of an in-board signal transmission path. With the goal.

In order to solve the above-described problems and achieve the object, a communication device according to the present invention includes a transmission line information storage unit that stores transmission line information indicating a configuration of an on-board signal transmission line; Adjustment information storage means for storing a plurality of candidates for signal voltage adjustment information for keeping the amplitude level of the signal voltage at both ends within a predetermined range for each of the transmission path information, and the transmission path stored by the transmission path information storage means Setting means for reading information and setting the signal voltage adjustment information of one of the plurality of candidates stored in the adjustment information storage means of the read transmission line information; and Signal output means for outputting a signal of a signal voltage corresponding to the signal voltage adjustment information to the signal transmission line.

  ADVANTAGE OF THE INVENTION According to this invention, in the communication apparatus, even when the structure of the signal transmission line in a machine differs, since the fall of the communication quality with external equipment can be suppressed, there exists an effect of ensuring communication quality.

FIG. 1 is a diagram illustrating an example of an appearance of the multifunction peripheral according to the first embodiment. FIG. 2 is a hardware block diagram related to USB communication between the multifunction peripheral and a general-purpose USB device connected to the multifunction peripheral. FIG. 3 is a diagram illustrating an example of a wiring method between a CPU and a DIP switch. FIG. 4 is a diagram illustrating an equivalent circuit of a transmission line. FIG. 5 is an explanatory diagram showing a relationship between a drive current value and a voltage amplitude level of a differential signal at a control board output terminal and a device output terminal. FIG. 6 is an explanatory diagram showing the relationship between the configuration of the in-machine transmission path and the drive current. FIG. 7 is a diagram illustrating transmission path information and setting information. FIG. 8 is a diagram showing an example of a drive current value initial setting operation flow. FIG. 9 is a diagram illustrating an example of the signal voltage adjustment information according to the first modification. FIG. 10 is a diagram illustrating an example of an initial setting operation flow. FIG. 11 is an explanatory diagram of the transmission path information and the setting information according to the second modification. FIG. 12 is a hardware block diagram related to USB communication between the multifunction peripheral according to the third modification and a general-purpose USB device connected to the multifunction peripheral. FIG. 13 is a diagram illustrating an example of a second relay cable according to the fourth modification. FIG. 14 is a hardware block diagram related to USB communication between a multifunction peripheral according to the fifth modification and a general-purpose USB device connected to the multifunction peripheral. FIG. 15 is a diagram for explaining a configuration example of the relay cable. FIG. 16 is a hardware block diagram related to USB communication of the multifunction peripheral according to the sixth modification. FIG. 17 is a diagram illustrating an example of a notification screen according to the eighth modification.

  Hereinafter, embodiments of a communication device, a method of controlling a signal voltage amplitude level, and a program will be described in detail with reference to the accompanying drawings. Hereinafter, an example in which the communication device is applied to a multifunction peripheral will be described.

(First Embodiment)
FIG. 1 is a diagram illustrating an example of an appearance of the multifunction peripheral according to the first embodiment. A multifunction peripheral 100 shown in FIG. 1 is a multifunction peripheral having functions of a scanner and a printer. The multifunction peripheral 100 includes an operation unit 11, a document feeder 12, and the like on an upper part of the main body 10. The document feeder 12 is provided on the glass surface of the document reading scanner directly below the document feeder 12 so as to be freely opened and closed. Further, the multifunction peripheral 100 mainly includes a paper feed unit including the paper feed tray 13, a part of the transport mechanism, and a printer from the middle to the lower part inside the main body 10. The multifunction peripheral 100 feeds the printing paper in the paper feeding tray 13 by a paper feeding unit, and transports the printing paper to a printer by a transport mechanism to form a print image. Then, the multifunction peripheral 100 discharges the printing paper printed by the printer from the discharge port.

  The operation unit 11 has a screen of a touch-type display 14 and a general-purpose USB (Universal Serial Bus) host connector 15 which are exposed to the outside. The touch-type display 14 is an operation unit provided with a touch panel on the screen of a display such as a liquid crystal display.

  The operation unit 11 further includes a relay board P2 (see FIG. 2) on which the general-purpose USB host connector 15 is mounted inside the housing. A control board P1 (see FIG. 2) for controlling each part of the multifunction peripheral 100 is housed in a housing on the back side of the main body 10.

  FIG. 2 is a hardware block diagram related to USB communication between the multifunction peripheral and a general-purpose USB device connected to the multifunction peripheral. The multifunction peripheral 100 shown in FIG. 2 includes a control board P1, and the control board P1 includes a CPU (Central Processing Unit) 101, a USB host controller 102, a DIP switch 103, a Flash ROM (Read Only Memory) 104, and a first USB host. It has a connector 105 and the like.

  In the multifunction peripheral 100, the control board P1 and the general-purpose USB host connector 15 are arranged at positions separated from each other due to a physical configuration. For this reason, the multifunction peripheral 100 further includes a relay board P2. The relay board P2 is provided with a relay connector 106 and the above-described general-purpose USB host connector (hereinafter, referred to as a second USB host connector) 15. The first USB host connector 105 and the relay connector 106 are connected in the machine by a relay cable 107 having a cable length suitable for the type of the multifunction peripheral 100. The second USB host connector 15 is connected to the USB device connector 20 of the general-purpose USB device device 200 by a general-purpose USB cable 30 outside the device. In the present embodiment, the relay cable 107 and the relay board P2 mainly constitute an on-board signal transmission path (hereinafter, the on-board signal transmission path is abbreviated as the on-board transmission path).

  The CPU 101 is a central processing unit. To the CPU 101, a USB host controller 102, a FlashROM 104, a touch-type display 14 (see FIG. 1), and interface circuits of various units are connected via a bus.

  The CPU 101 executes a control program and the like stored in the flash ROM 104 to control the entire multifunction peripheral 100. As one of the processes, the CPU 101 performs an initialization process described later for setting a drive current value in the USB host controller 102.

  The USB host controller 102 has a drive current value setting register, and drives the current with the drive current value set in the setting register. The USB host controller 102 further includes an output circuit, and converts the data output from the CPU 101 into a differential signal by the current driving based on the driving current value and outputs the data to a signal transmission path. This differential signal is output at a voltage amplitude level according to the setting of the drive current value of the setting register. Note that the USB host controller 102 supports transfer modes such as low speed, full speed, and high speed. When the multifunction peripheral 100 and the general-purpose USB device 200 are connected by the general-purpose USB cable 30, the USB host controller 102 determines the transfer mode of the general-purpose USB device 200 and transmits a signal in a higher-speed transfer mode.

  The DIP switch 103 is a DIP switch for setting transmission line information indicating the configuration of the internal transmission line. The DIP switch 103 has, for example, eight switches, and sets High “1” or Low “0” by switching each switch. The transmission path information indicated by the set 8-bit signal is read when the CPU 101 executes a USB initialization program or the like. The wiring method between the DIP switch 103 and the CPU 101 will be described later with reference to the drawings.

  The FlashROM 104 stores a control program and various data. The control program also includes a USB initial setting program and the like. The various data includes information indicating a drive current value that can be set in a setting register of the USB host controller 102 (hereinafter, also referred to as signal voltage adjustment information), various screen information (for example, screen information of initial setting), and the like. .

  The relay board P2 is a relay board that relays a transmission signal between the USB host controller 102 and the general-purpose USB device 200. The pattern 108 is a circuit pattern of a transmission line provided on the relay board P2.

  The relay cable 107 is a cable conforming to the USB standard. Specifically, it is composed of + D and -D data lines for transmitting differential signals, power supply lines, and GND. The + D and -D data lines are stranded and bundled for noise reduction.

Next, the wiring method between the DIP switch 103 and the CPU 101 will be described.
FIG. 3 is a diagram illustrating an example of a wiring method between the CPU 101 and the DIP switch 103. FIG. 3 shows a configuration in which input ports n1 to n8 of the CPU 101 are connected by pull-up resistors r1 to r8, respectively. In this wiring method, the switches SW1 to SW8 of the DIP switch 103 are respectively switched, so that the input states of the input ports n1 to n8 become HIGH “1” or LOW “0”, respectively.

  For example, when the switch SW1 is closed, the input port n1 becomes LOW “0”, and when the switch SW1 is opened, the input port n1 becomes HIGH “1”. Therefore, when all the switches SW1 to SW7 are closed and only the switch SW8 is opened, the input port n1, the input port n2,..., The input port n8 are 0, 0, 0, 0, 0, 0, 0, This means that an 8-bit signal of "00000001" is input to the CPU 101.

  The wiring between the DIP switch 103 and the CPU 101 is not limited to a pull-up connection, but may be a pull-down connection.

  Subsequently, control of the amplitude voltage level will be described by taking a high speed mode as an example.

  FIG. 4 is a diagram showing an equivalent circuit of the transmission line in the hardware block diagram shown in FIG. In FIG. 4, a first circuit A1 is an equivalent circuit related to an output circuit of the USB host controller 102. The second circuit A2 is an equivalent circuit relating to an in-machine transmission line from the output terminal T1 of the output circuit to the output terminal T2 of the multifunction peripheral 100. The third circuit A3 is an equivalent circuit related to the input circuit of the general-purpose USB device 200.

  Note that the output terminal T1 of the output circuit and the output terminal T2 of the multifunction device constitute "both ends of the in-machine transmission path". In the present embodiment, the output terminal T1 is an output signal terminal of the first USB host connector 105 (see FIG. 2), and the output terminal T2 is an output signal terminal of the second USB host connector 15 (see FIG. 2). Signal terminal. Hereinafter, the output terminal T1 is replaced with the control board output terminal T1, and the output terminal T2 is replaced with the device output terminal T2.

  The constant current source A10 shown in the first circuit A1 is a constant current circuit of the USB host controller 102. The constant current source A10 fixes the drive current to the drive current value set in the setting register. For example, when data indicating “0%” is set as the drive current value in the setting register, the drive current is fixed to the standard value of the current value in the high speed mode (17.8 mA). When data indicating “+ 10%” is set, the drive current is fixed to a value that is increased by 10% from the standard value (17.8 mA).

  A resistor R1 shown in the first circuit A1 is an output termination resistor of the output circuit. In the high speed mode, the standard value of the resistor R1 is 45Ω.

  The resistance component R2 and the capacitance component C1 shown in the second circuit A2 indicate the impedance included in the internal transmission path. The resistance component R2 indicates a DC resistance component of the in-machine transmission line, and the capacitance component C1 indicates an AC resistance component. The impedance shows a different value depending on the configuration of the in-machine transmission line (for example, the cable length of the relay cable 107, the pattern length of the relay board P2, and the like).

  The resistor R3 shown in the third circuit A3 is an input termination resistor of the input circuit of the general-purpose USB device 200. In the high speed mode, the standard value of the resistor R3 is 45Ω.

  In an ideal configuration not including the resistance component R2 and the capacitance component C1 of the second circuit A2, the following equation (1) is satisfied in the high-speed mode.

  Voltage amplitude level = Terminal resistance / 2 × Current value of drive current (1)

  Accordingly, the amplitude level of the voltage when the current value is the standard value (17.8 mA) is 45Ω / 2 × 17.8 mA = 400 mV.

  FIG. 5 is an explanatory diagram showing the relationship between the drive current value and the voltage amplitude level of the differential signal at the control board output terminal T1 and the device output terminal T2. The horizontal axis of FIG. 5 indicates the drive current value (X) of the constant current source A10, and the vertical axis indicates the amplitude level (Y) of the voltage of the differential signal.

  A hatched portion E shown in FIG. 5 represents a range of the voltage amplitude level satisfying the USB standard (an example of the “predetermined range”). As indicated by the hatched portion E, the USB standard has an upper limit and a lower limit in the voltage amplitude level. At each point (test point) such as the control board output terminal T1 and the device output terminal T2, the signal amplitude on the receiving side is ensured by the voltage amplitude level falling within the shaded area E.

  In the example shown in FIG. 5, the graph G1 shows the relationship between the drive current value of the ideal configuration of the in-machine transmission line where the impedance of the in-machine transmission line has the value “0” and the voltage amplitude level of each test point. In an ideal configuration where the impedance value of the in-machine transmission line = 0, the voltage amplitude level at each test point shows the same value. Therefore, the relationship between the drive current value and the voltage amplitude level at each test point is represented by one graph G1. This also applies to a case where the length of the in-machine transmission path is “0” or close to “0”. In an ideal configuration, if the drive current value is set in the range from the drive current value X1 to the drive current value X2, the voltage amplitude level at the device output terminal T2 falls within the shaded area E. Of course, if the drive current value is set to the standard 17.8 mA, a voltage amplitude level of the standard value (400 mV) in the shaded portion E can be obtained.

  In the multifunction peripheral 100 according to the present embodiment, the control board P1 and the second USB host connector 15 are located apart from each other due to the physical configuration, and therefore, it is necessary to connect them via the relay cable 107 or the like. Therefore, the impedance of the in-machine transmission line tends to increase according to the configuration of the in-machine transmission line. The method of setting the range of the drive current value when the configuration of the in-machine transmission line cannot be ignored is as follows.

  Graphs G2 and G3 shown in FIG. 5 are examples of the relationship between the drive current value and the voltage amplitude level at the control board output end T1 and the apparatus output end T2 when the connection is made inside the machine by the relay cable 107 and the relay board P2, respectively. Is shown. As shown by the graphs G2 and G3, the gap (arrow Z) of the voltage amplitude level at each test point tends to relatively widen as the drive current value increases.

  Here, if the range of the drive current value is set based on the voltage amplitude level of the device output terminal T2 shown by the graph G3, the drive output value can be set in the range from the drive current value a1 to the drive current value a2. The voltage amplitude level of T2 falls within the shaded area E. However, if the driving current value is set in a range from the driving current value b1 to the driving current value a2 shown in FIG. 5 without considering the graph G2, the voltage amplitude level of the control board output terminal T1 shown in the graph G2 becomes a hatched portion E in that range. Will get out of the way. That is, the output signal of the control board output terminal T1 is out of the standard, and the signal quality on the receiving side cannot be guaranteed. Therefore, the driving current value is set in the range of the driving current value a1 to the driving current value b1 in consideration of the graph G2.

  As described above, in the multifunction peripheral 100 according to the present embodiment, the range of the drive current value is set such that the voltage amplitude level of each test point is within the shaded area E.

  Note that the graphs G2 and G3 show that the voltage amplitude level in the hatched portion E can be obtained at each test point even when the drive current value is set to the standard 17.8 mA. However, in each of the graphs G2 and G3, the configuration of the transmission line is changed by, for example, increasing the length of the transmission line in the machine, and when the impedance of the transmission line in the machine is increased, the gap of the voltage amplitude level is further widened and changed from the standard value. Is required. As described above, when a change from the standard value is required, it is necessary to consider not only the graph G3 but also the graph G2 as described above.

  FIG. 6 is an explanatory diagram showing the relationship between the configuration of the in-machine transmission path and the drive current. The horizontal axis of FIG. 6 is a configuration number (configuration number 1, configuration number 2,...) Indicating the length of the in-machine transmission path, and the vertical axis is the amplitude level of the voltage of the differential signal (FIG. 5). Y). A hatched portion E indicates a range satisfying the USB standard as in FIG.

  Here, the configuration number is a number obtained by grouping the configuration of the internal transmission path according to the length of the internal transmission path. As an example, configuration number 1 (250 mm ≧ in-machine transmission line length), configuration number 2 (500 mm ≧ in-machine transmission line length> 250 mm), configuration number 3 (750 mm ≧ in-machine transmission line length> 500 mm), configuration number 4 (1000 mm ≧ in-machine transmission line) It is assumed that the transmission line length is> 750 mm, the configuration number is 5 (1250 mm ≧ the transmission line length in the machine> 1000 mm), and so on. In the present embodiment, as an example, the length of the in-machine transmission path is set to a length that can ignore the pattern length of the relay board P2, and is limited to the cable length of the relay cable 107 (in-machine cable length).

  The solid line graph g1 is an example of a graph showing the voltage amplitude level of the differential signal for each configuration number when the drive current is fixed to a standard value. In the solid line graph g1, a rising straight line g1-1 is a graph showing a change in the voltage amplitude level at the control board output terminal T1, and a falling straight line g1-2 is a change in the voltage amplitude level at the device output terminal T2. FIG.

  The broken line graph g2 is a graph showing a change in the voltage amplitude level of the differential signal for each configuration number when the drive current is increased by 10% from the standard value. In the dashed-line graph g2, a straight line g2-1 rising to the right indicates a change in the voltage amplitude level at the control board output terminal T1, and a straight line g2-2 falling to the right indicates a change in the voltage amplitude level at the device output terminal T2. The broken line graph g3 is a graph showing a change in the voltage amplitude level of the differential signal for each configuration number when the drive current is increased by 20% from the standard value. In the dashed-line graph g3, a straight line g3-1 rising to the right indicates a change in the voltage amplitude level at the control board output terminal T1, and a straight line g3-2 falling to the right indicates a change in the voltage amplitude level at the device output terminal T2. Although not shown in FIG. 6, a case where the drive current is reduced by 10% from the standard value and a case where the drive current is reduced by 20% are appropriately included. For example, when the drive current is reduced from the standard value, the solid line graph g1 is shifted in the negative direction of the Y-axis according to the reduction rate.

  The correspondence between the configuration number and the drive current value information (signal voltage adjustment information) in the FlashROM 104 is as follows as an example. For example, consider a configuration number 5 (1250 mm ≧ in-machine cable length> 1000 mm). In the configuration number 5, the value of the Y coordinate of the intersection Q1 with the straight line g1-1 of the solid line graph g1 is Y1, and the value of the Y coordinate of the intersection Q2 with the straight line g1-2 is Y2. That is, when the drive current value is set to the standard value, the voltage amplitude level of the device output terminal T2 is lower than the lower limit value of the hatched portion E in the in-machine cable length of the configuration number 5. Therefore, it is necessary to shift the graph g1 upward as indicated by the arrow Z1.

  In the example shown in FIG. 6, by increasing the standard value by 10%, a dashed line graph g2 is obtained. The values of the Y coordinates of the intersections Q3 and Q4 of the straight line g2-1 and the straight line g2-2 are Y3 and Y4, respectively. Become. Since the voltage amplitude levels of both Y3 and Y4 fall within the shaded area E, the drive current value increased by 10% from the standard value conforms to the standard.

  Further, in the example shown in FIG. 6, the same can be said for a case where the standard value is increased by 20%. When it is increased by 20% from the standard value, it becomes a broken line graph g3, and the values of the Y coordinates of the intersections Q5 and Q6 of the straight line g3-1 and the straight line g3-2 are Y5 and Y6. Both Y5 and Y6 conform to the standard because the voltage amplitude level falls within the shaded area E. In this case, since both the 10% increase and the 20% increase match, one of them is determined as the signal voltage adjustment information.

  The signal voltage adjustment information suitable for each configuration number is determined by the above-described method, and is set in association with the FlashROM 104. The setting information may be input by the user, or the data shown in FIG. 6 may be stored in the flash ROM 104 and the automatic program may be set. The setting information may be provided by being stored in the FlashROM 104 in advance, or may be copied to the FlashROM 104 later.

  FIG. 7 is a diagram showing transmission path information and setting information based on each graph shown in FIG. FIG. 7A is a configuration table of transmission line information set in the DIP switch 103, and FIG. 7B is setting information stored in the Flash ROM 104.

  The transmission path configuration table F1 shown in FIG. 7A is a configuration table showing the correspondence between the configuration number f1 and the in-machine cable length f2. Here, the in-machine cable length f2 is an item in which the range of the in-machine cable length is set. A worker who newly assembles the relay cable 107 or a maintenance worker who replaces the relay cable 107, when assembling the relay cable 107 or the like, changes the configuration number indicating the length of the relay cable 107 according to the transmission path configuration table F1. It is set in the DIP switch 103 as transmission line information. For example, from the transmission path configuration table F1, read the number of the configuration number f1 associated with the corresponding in-flight cable length of the in-flight cable length f2, and set each switch of the DIP switch 103 to “1” or Switch to "0". In the present embodiment, a value obtained by converting a configuration number represented by a decimal number into a binary number (a binary number “00000100” if the decimal number is “5”) is set.

  The setting information D1 illustrated in FIG. 7B is information in which the configuration number d1 (corresponding to the configuration number f1 in FIG. 7A) is associated with the signal voltage adjustment information d2. In the present embodiment, the signal voltage adjustment information d2 indicates the rate of increase or decrease of the drive current based on the standard 17.8 mA in percentage (%) for the sake of explanation. “Setting impossible” in the signal voltage adjustment information d2 indicates that there is no suitable drive current value.

  Next, an initial setting operation for the USB in the multifunction peripheral 100 will be described. The setting operation is performed once after the new installation of the relay cable 107, after the replacement of the relay cable 107, or after rewriting the setting information D1 (see FIG. 7). For example, an operator sets the DIP switch 103 after attaching the relay cable 107. Thereafter, the operator activates the system of the multifunction peripheral 100, touches the initial setting screen of the display 14, and instructs the CPU 101 to start the USB initial setting operation. The CPU 101 reads the initial setting program stored in the Flash ROM 104 according to the input command and executes the following processing.

  FIG. 8 is a diagram showing an example of a drive current value initial setting operation flow by the CPU 101. First, the CPU 101 reads an 8-bit configuration number (corresponding to the configuration number f1: see FIG. 7) set by the DIP switch 103 (S1).

  Subsequently, the CPU 101 extracts signal voltage adjustment information corresponding to the read configuration number from the setting information D1 of the FlashROM 104 (see FIG. 7) (S2).

  Then, the CPU 101 sets the extracted signal voltage adjustment information in the drive current value setting register of the USB host controller 102 (S3), and ends this processing.

  As described above, in the subsequent USB communication, the USB host controller 102 is driven by the drive current value set in the setting register.

  In the present embodiment, the setting information D1 (see FIG. 7) stored in the FlashROM 104 is set based on the relationship between the configuration of the in-machine transmission path and the drive current (see FIG. 6). The relationship shown in FIG. 6 changes for each control board in accordance with the configuration of the control board P1, for example, the configuration of a signal transmission path between the USB host controller 102 and the first USB host connector 105. Therefore, it is preferable that the setting information corresponding to the control board be stored in the Flash ROM 104.

  In the present embodiment, the classification of the length of the in-machine cable length shown in the transmission path configuration table F1 (see FIG. 7) and the pitch of the increase rate of the signal voltage adjustment information shown in the setting information D1 (see FIG. 7) are examples. These settings may be appropriately modified. For example, the in-machine cable length may be classified more finely. Further, the pitch of the increase rate of the signal voltage adjustment information may be set to a value smaller than 10%. Further, the pitch may be modified so as to increase or decrease in units such as 1 mA.

  When the common control board P1 is mounted on a plurality of devices having different specifications, a combination of a configuration number corresponding to various configurations of the in-machine transmission line and signal voltage adjustment information is stored in advance in the FlashROM 104 as setting information. It is preferable to keep it. In this case, also in the transmission path configuration table, the configuration number is associated with the in-machine cable length accordingly.

  In the present embodiment, the flash ROM has been described as an example of the storage unit of the signal voltage adjustment information, but another storage unit may be used. For example, a ROM or a HDD (Hard Disk Drive) may be used. Further, in this embodiment, the USB host controller is shown as being separate from the CPU, but may be integrated with the CPU.

  The general-purpose USB device device 200 according to the present embodiment is an external device such as a peripheral device that operates as a USB device device with respect to the USB host controller 102. The general-purpose USB device device 200 can ensure good communication quality with the USB host controller 102 regardless of which device operates as a USB device device.

  In the present embodiment, the DIP switch 103 and a circuit that outputs the setting state to the CPU 101 are provided as the “transmission path information storage unit”. In addition, a FlashROM 104 storing setting information D1 is provided as “adjustment information storage means”. Further, a USB host controller 102 having a setting register is provided as “signal output means”. The “setting unit” is realized as a functional unit by the CPU 101 executing an initial setting program stored in the Flash ROM 104, and stores the signal voltage adjustment information of the setting information D1 corresponding to the configuration number set in the DIP switch 103 as described above. Set in the setting register.

  With the above configuration, in the multifunction peripheral of the present embodiment, the amplitude level of the signal voltage at each point of the signal transmission path in the apparatus can be adjusted so as to be within a predetermined range according to the configuration of the internal transmission path. For this reason, even when the configuration of the in-machine transmission path is different, it is possible to suppress a decrease in the communication quality with the external device, and secure the communication quality with the external device.

(Modification 1)
As a first modification of the multifunction peripheral of the embodiment, a multifunction peripheral provided with a plurality of adjustment widths (candidates of the signal voltage adjustment information) of the signal voltage adjustment information d2 indicated in the setting information D1 (see FIG. 7) will be described.

  FIG. 9 is a diagram illustrating an example of the signal voltage adjustment information according to the first modification. The signal voltage adjustment information D2 shown in FIG. 9 is obtained by associating the adjustment number availability information d3 with the configuration number d1 shown in the setting information D1. The adjustment width availability information d3 has, as items of the adjustment width d30, items indicating the adjustment widths of -30%, -20%, -10%, 0%, + 10%, + 20%, and + 30%. Availability information (“「 ”or“ × ”/“ ○ ”or“ × ”) is set. The adjustment width availability information d3 has an item of an adjustment range d31. Note that “0%” of the adjustment width d30 indicates a standard 17.8 mA, as in the embodiment, “+ 10%” indicates a 10% increase in the standard, and “−10%” indicates a 10% decrease in the standard. Is shown.

  The availability information ("o" or "x" / "o" or "x") indicates the availability information of the control board output terminal T1 / the availability information of the device output terminal T2 before and after "/". For example, “○ / ×” is set as the propriety information when the drive current value of the configuration number 5 is set to 0% of the standard. This indicates that the standard is satisfied at the control board output terminal T1 (“（”), but not at the device output terminal T2 (“x”). In the configuration number 5, the adjustment ranges satisfying the standards at both the control board output end T1 and the device output end T2 are “+ 10%” and “+ 20%” indicated by “O / O”.

  The adjustment range d31 indicates the range of the adjustment width. For example, in the configuration number 5, since “+ 10%” and “+ 20%” are “○ / ○”, the signal voltage adjustment information can be set at an arbitrary increase rate within a range from + 10% to + 20%. Is shown. “NG” indicates that there is nothing that can be set, including the standard value.

  A setting operation when the adjustment width d30 of the signal voltage adjustment information D2 of the first modification is used will be described.

  FIG. 10 is a diagram illustrating an example of an initial setting operation flow of the first modification. First, the processing from step S11 to step S14 will be described.

  First, the CPU 101 reads the 8-bit configuration number set by the DIP switch 103, similarly to step S1 of FIG. 8 (S11).

  Subsequently, the CPU 101 extracts, from the signal voltage adjustment information D2 stored in the FlashROM 104, a pair of the adjustment width and the availability information of the adjustment width availability information d3 corresponding to the configuration number read in step S11 (S12).

  Then, the CPU 101 selects one of the adjustment widths for which the availability information is “O / O” from the pair as the signal voltage adjustment information to be set in the setting register (S13). This selection may be made by an appropriate method. Here, as an example, it is assumed that the adjustment range having the lowest increase / decrease rate is selected from the adjustment ranges in which the availability information is “増 減 / ○”.

  Subsequently, the CPU 101 sets the selected adjustment width in the drive current value setting register of the USB host controller 102 as signal voltage adjustment information (S14). After the CPU 101 sets the setting register in step S14, the USB host controller 102 drives with the drive current value indicated by the adjustment width.

  It is assumed that the adjustment width once selected is found to be of poor quality, such as an error in subsequent USB communication. In that case, the initial setting screen may be called again by a touch operation of an operator or the like, and a resetting operation using another adjustment width may be performed.

  Steps S21 to S26 shown in FIG. 10 show the processing. For example, a reset button is provided on the initial setting screen, and the operator touches the reset button (S21). When the CPU 101 detects the touch operation of the reset button (Step S21: Yes determination), the CPU 101 displays on the screen the number-of-adjustment-number-up buttons such as "1 step", "2 steps", and "3 steps". The touch operation of the up number button by the user is received (S22).

  Subsequently, upon detecting the touch operation of the up number button, the CPU 101 temporarily stores the number of up operations (for example, “1 step”), and then proceeds to steps S11 to S24 in FIG. The same processing as in S12 is performed.

  Subsequently, based on the temporarily stored number of increments (“one step”), the CPU 101 increases or decreases the step extracted by step S24 by one step higher than the selection criterion among the adjustment ranges in which the availability information is “と / ○”. A rate adjustment range is selected (S25). In this example, since the selection criterion is set to the lowest change rate, the adjustment range of the change rate one step higher from the lowest change rate is selected. For example, if the lowest change rate is “+ 10%”, the change rate one step higher is “+ 20%”.

  Then, the CPU 101 sets the extracted adjustment width in the drive current value setting register of the USB host controller 102 as signal voltage adjustment information (S26), and ends this processing.

  As described above, in the subsequent USB communication, the USB host controller 102 drives with the drive current value reset in the setting register.

  In the processing described above, the adjustment width d30 of the signal voltage adjustment information D2 is used, but the adjustment range d31 may be used. In this case, after the touch operation of the reset button (step S21: Yes determination), an input button of the step size is displayed on the screen in addition to the number-of-ups button, and the operator inputs the number of steps and the step size. In step S25, based on the inputted number of increments and the step size, the CPU 101 selects one of the adjustment ranges of the pair extracted in step S24 where the propriety information becomes “○ / ○”, based on the selection criterion. Select a high rate of change. For example, it is assumed that the selection criterion is the one with the lowest increase / decrease rate, and the step size “1” and the number of increments “3 steps” are input. In this case, assuming that the lowest change rate is “+ 10%”, it becomes +10 (%) + 1 (interval) × 3 (stage) = + 13 (%).

  The above is an example in which only the adjustment width of the drive current is changed without changing the in-machine cable length. However, this is not the case when the relay cable 107 is replaced and the DIP switch 103 is reset. In such a case, the flow of the initial setting operation in FIG. 8 may be performed again without operating the reset button.

  In the first modification, a reset button, a number-of-ups button, a step size input button, and the like are provided on the initial setting screen as “resetting instruction means”.

  As described above, in the first modification, by providing a plurality of adjustment widths of the signal voltage adjustment information indicated by the setting information, one specified from the plurality of adjustment widths can be set in the setting register. Further, the provision of the reset setting means makes it possible to reset the adjustment width different from the adjustment width once set in the setting register.

(Modification 2)
As a modified example 2 of the multifunction peripheral of the embodiment, a case where a pattern length of a relay board is added to an in-machine transmission path length will be described.

  FIG. 11 is an explanatory diagram of the transmission path information and the setting information according to the second modification. These correspond to the respective graphs shown in FIG. FIG. 11A is a configuration table of transmission line information set in the DIP switch 103, and FIG. 11B is setting information stored in the Flash ROM 104.

  The transmission path configuration table F20 of Modification 2 shown in FIG. 11A is a configuration table showing the correspondence among the configuration number f1, the relay board pattern length f20, and the in-machine cable length f2. An operator who newly assembles the relay cable 107 or the relay board P2, or a maintenance worker who replaces the relay cable 107 or the relay board P2, can use the relay board P2 from the transmission path configuration table F20 when assembling the relay board P2 or the relay cable 107. The configuration number corresponding to the pattern length of the relay cable 107 and the in-machine cable length of the relay cable 107 is read, and the number is set in the DIP switch 103. For example, when the relay board P2 satisfies 200 mm ≧ pattern length> 100 mm, the configuration numbers 9 to 16 of the configuration number f1 correspond thereto. Further, if the relay cable 107 is 1750 mm ≧ in-machine cable length> 1500 mm, the configuration number 15 of the configuration numbers 9 to 16 of the configuration number f1 corresponds. The operator reads the configuration number 15 from the transmission path configuration table F20, and sets a binary number (000000101) in the DIP switch 103.

  The setting information D20 of the second modification shown in FIG. 11B is information in which the configuration number d1 and the signal voltage adjustment information d2 are associated with each other, like the setting information D1 shown in FIG. The setting information D20 of Modification 2 is information indicating eight configuration numbers and drive current values for each of three groups of pattern lengths (groups of 100 mm or less, 200 mm or less, and 300 mm or less) by adding the pattern length of the relay board P2. Are associated with each other.

  In the setting information D20 shown in FIG. 11B, the pattern length of the relay board P2 for the configuration numbers 1 to 8 is as short as 100 mm or less. For this reason, in this example, the increase in impedance due to the pattern length is ignored, and the same value as the setting information D1 shown in FIG. For the configuration numbers 9 to 16 and the configuration numbers 17 to 24, since the pattern length exceeds 100 mm, the drive current can be set according to the length of the pattern without ignoring the increase in impedance. Range has changed. For example, focus on the configuration numbers 11 and 19 having the same in-machine cable length as the in-machine cable length of the configuration number 3 (750 mm ≧ in-machine cable length> 500 mm). The adjustment width of the configuration number 3 is 0% as a standard, but the adjustment width of both the configuration numbers 11 and 19 in consideration of the pattern length increases to + 10%.

  When performing the setting operation using the setting information D20, the operator sets the corresponding number to the DIP switch 103 from the configuration numbers 1 to 24 of the transmission path configuration table F20. The operation of the CPU 101 is the same as that of the embodiment except that the setting information D20 stored in the FlashROM 104 is read, and thus the description is omitted.

  In the second modification, one signal voltage adjustment information is set for each configuration number in the setting information D20. However, as shown in the first modification, a plurality of adjustment ranges of the signal voltage adjustment information may be provided. Needless to say.

(Modification 3)
As a third modification of the multifunction peripheral of the embodiment, a configuration of the multifunction peripheral when transmission path information is provided on a relay board will be described. Hereinafter, description overlapping with the embodiment will be appropriately omitted, and portions different from the embodiment will be described.

  FIG. 12 is a hardware block diagram related to USB communication between the multifunction peripheral according to the third modification and a general-purpose USB device connected to the multifunction peripheral. 12, the same parts as those in the configuration of the hardware block of the multifunction peripheral 100 shown in FIG. 2 are denoted by the same reference numerals.

  In the multifunction peripheral 300 shown in FIG. 12, the control board P1 has an I / O 301. The relay board P2 has a DIP switch 302.

  The I / O 301 is an input / output circuit including eight input ports and eight output ports. The eight output ports are connected to the CPU 101, and the eight input ports are connected to the DIP switch 302 of the relay board P2 by pull-up. The pull-up wiring method is the same as the wiring method of the CPU 101 and the DIP switch 103 described in the embodiment (see FIG. 3) except that the CPU 101 is replaced with the I / O 301, and therefore detailed description is omitted here.

  The DIP switch 302 is for setting transmission line information, and has the same configuration as that of the DIP switch 103 shown in the first embodiment. The setting of the transmission path information for the DIP switch 302 may be performed by an operator when assembling the relay board P2. Alternatively, the relay board P2, the relay cable 107, and the signal line 303 may be provided as a set in a state where transmission path information is set in the DIP switch 302 in advance.

  The signal lines 303 represent eight signal lines that connect the eight input ports of the I / O 301 and the terminals of the eight switches included in the DIP switch 302. Both ends of the signal line 303 are provided with 8-pin connectors. The signal line 303 is connected to an 8-pin connector 304 provided on the control board P1 and connected to eight input ports of the I / O 301, and to terminals of eight switches of the DIP switch 302 provided on the relay board P2. The 8-pin connector 305 is connected to connectors at both ends of the signal line 303.

  Next, an initial setting operation for the USB in the multifunction peripheral 300 will be described. The setting operation is substantially the same as the processing flow of the initial setting operation shown in the embodiment (see FIG. 8) except that the transmission line information set in the DIP switch 302 is read from the I / O 301. Further, in the case where the transmission path information in which the DIP switch 302 is set in advance is used, the setting work is not required.

  That is, the worker instructs the CPU 101 to start the USB initial setting operation after attaching the relay cable 107, the signal line 303, and the like. The CPU 101 reads the 8-bit configuration number set in the DIP switch 302 from the I / O 301 in step S1. Further, in step S2, the CPU 101 extracts corresponding signal voltage adjustment information from the setting information D1 of the FlashROM 104 (see FIG. 7). Then, the CPU 101 sets the extracted signal voltage adjustment information in the drive current value setting register of the USB host controller 102.

  In the third modification, an example has been described in which the transmission path information is set by the DIP switch 302 on the relay board P2, and the setting data is input to the I / O 301 in parallel. However, it is also possible to convert the data from parallel to serial on the relay board P2 and input the setting data serially to the I / O 301.

  In the third modification, the example in which the transmission path information is set by the DIP switch 302 in the relay board P2 has been described, but a memory such as a ROM storing the transmission path information may be provided in the relay board P2. In this case, the control board P1 and the relay board P2 transfer the transmission line information of the memory from the relay board P2 to the control board P1 by providing a communication circuit or the like. The CPU 101 reads and uses the transmission path information transferred by the communication circuit. Note that the communication is not limited to a wired communication but may be a wireless communication. In the case of wireless communication, for example, an RFID may be used. In this case, the RFID tag on which the transmission path information is written is embedded in the relay board P2, and the control board P1 is provided with an RFID reader to read the transmission path information. The CPU 101 uses the transmission path information read by the RFID reader.

  As described above, in the configuration of the third modification, the transmission path information is provided on the relay board. In particular, if the relay board P2, the relay cable 107, and the like are exchanged as a set in a state where the transmission line information is set in advance by the DIP switch 302 or the like, it is not necessary to set the transmission line information every time the exchange is performed. For this reason, the labor of the operator is reduced, and a setting error or the like can be prevented.

(Modification 4)
As a fourth modification of the multifunction peripheral of the embodiment, a configuration in which the relay cable and the signal line for transmission path information shown in the third modification are combined into one cable will be described.

  FIG. 13A is a diagram illustrating an example of a configuration of a second relay cable according to the fourth modification. The second relay cable 401 shown in FIG. 13 includes USB + D and -D data lines 40 and 41, a power supply line 42, a GND 43, and a signal line 44 for transmission path information. Here, one signal line for serial transmission is illustrated as the signal line 44. The + D and -D data lines 40 and 41 are stranded to reduce noise. Each of the lines 40 to 44 is configured as a single cable by being covered with a shield 45.

  FIG. 13B is a diagram illustrating an example of the appearance of the second relay cable 401. A second relay cable 401 shown in FIG. 13B shows a configuration in which each line 40 to 44 and a corresponding connector (plug connector) are connected at both ends of the cable. Specifically, the + D and -D data lines 40 and 41 of the USB, the power supply line 42, and the GND 43 are connected to the USB connector plug 46, and the signal line 44 for transmission path information is connected to the pin terminal 47. I do.

  Note that a dedicated connector plug (one connector plug having a five-terminal configuration in this example) may be prepared, and the lines 40 to 44 may be connected to the dedicated connector plug at both ends of the cable. In this case, the first USB host connector 105 of the control board P1 and the second USB host connector 15 of the relay board P2 are also changed to correspond to the dedicated connector (in this example, a connector having a five-terminal configuration).

  Further, the dedicated connector may be connected to the first USB host connector 105 of the control board P1 and the second USB host connector 15 of the relay board P2 by using a conversion connector.

  The USB + D and -D data lines 40 and 41, the power supply line 42, and the GND 43 are shielded, and the signal line 44 for transmission path information is separately shielded and bundled into one cable. Is also good.

(Modification 5)
As a fifth modification of the multifunction peripheral of the embodiment, a configuration of the multifunction peripheral when transmission path information is provided in a relay cable will be described. Hereinafter, description overlapping with the embodiment will be appropriately omitted, and portions different from the embodiment will be described.

  FIG. 14 is a hardware block diagram related to USB communication between a multifunction peripheral according to the fifth modification and a general-purpose USB device connected to the multifunction peripheral. 14, the same parts as those in the hardware block configuration of the multifunction peripheral 100 shown in FIG. 2 are denoted by the same reference numerals.

  In the MFP 500 shown in FIG. 14, the control board P1 has an I / O 301. The relay cable 501 is obtained by combining a USB cable and a signal line 44 for transmission path information as shown in Modification Example 4 into one cable. A relay cable 501 according to the fifth modification has a built-in DIP switch 50, and is used to output a USB connector 51 (see FIG. 15) and transmission line information to one end of the cable (the side connected to the control board P1). A connector 52 (see FIG. 15) is provided. The other end is only a USB connector 53 (see FIG. 15).

  FIG. 15 is a diagram illustrating a configuration example of the relay cable 501. A relay cable 501 shown in FIG. 15 includes a DIP switch 50 on a connector 51. On the surface of the connector 51, a slide portion for switching the respective switches SW1, SW2,... Of the DIP switch 50 by sliding is provided so as to be exposed so as to be switchable by an operator.

  As shown in FIG. 15, each of the switches SW1, SW2,... Of the DIP switch 50 has a terminal connected to the signal line 44.

  When connected to the control board P1, the relay cable 501 is connected to connector pins PIN1 to PIN4, PIN5, PIN6,... Of the control board P1 indicated by arrows in FIG. .. Are connected to the input ports n11, n12,... Of the I / O 301 by pull-up resistors r1, r2,. You.

  The I / O 301 is an input / output circuit including eight input ports and eight output ports similar to the I / O 301 (see FIG. 12) shown in the third modification. The eight output ports are connected to the CPU 101.

  The DIP switch 50 is for setting transmission line information, and has the same configuration as the DIP switch 103 described in the embodiment. The setting of the transmission path information for the DIP switch 50 may be performed by an operator when the relay cable 501 is assembled. In addition, the transmission path information may be set in advance in the DIP switch 50 and provided with the relay board P2 or the like, for example.

  The relay cable 501 has USB + D and -D data lines 40 and 41, a power supply line 42, a GND 43, and a signal line 44 for transmission path information.

  The USB initial setting operation in the multifunction peripheral 500 is the same as that in the third modification. Therefore, the description here is omitted.

  In the fifth modification, similarly to the third modification, the transmission path information may be set by the DIP switch 50 on the relay board P2, the setting data may be converted from parallel to serial, and then input to the I / O 301 serially. .

  Further, the configuration is not limited to the configuration in which the setting can be changed like the DIP switch 50, but may be a configuration in which the setting is fixed to a constant value. For example, in FIG. 15, the DIP switch 50 is removed, and each line of the signal line 44 is open (including pull-up connection) when the input state is HIGH “1”, and GND when the input state is LOW “0”. Fixedly connected to Thus, the input state of each signal line 44 is always fixed to the value indicated by the transmission path information. Further, similarly to the third modification, a memory such as a ROM storing transmission path information may be provided in the relay cable 501. For example, a communication circuit such as RS232C is provided, and the transmission path information in the memory is read by the CPU 101 by communication. In addition, an RFID tag in which transmission path information is written may be embedded in the relay board P2, and an RFID reader may be provided on the control board P1 to read the transmission path information.

(Modification 6)
In Modification 6 of the multifunction peripheral of the embodiment, a multifunction peripheral having a plurality of USB connection ports will be described as an example of a configuration having a plurality of signal transmission paths inside the multifunction peripheral. Hereinafter, description overlapping with the embodiment will be appropriately omitted, and portions different from the embodiment will be described.

  FIG. 16 is a hardware block diagram related to USB communication of the multifunction peripheral according to the sixth modification. The multifunction peripheral 600 shown in FIG. 16 includes a hub 601 on the control board P1. The hub 601 has a plurality of USB ports on the downstream side, and one set of a relay cable and a relay board is connected to each USB port. The control board P1 includes an I / O 602 and two DIP switches 603-1 and 603-2.

  In the example shown in FIG. 16, the hub 601 has two USB ports (a first USB port 604 and a second USB port 605), and the USB ports 604 and 605 respectively have a relay cable 107-1 and a relay cable 107-1. The signal transmission path of the board P2-1 and the signal transmission path of the relay cable 107-2 and the relay board P2-2 are configured.

  The I / O 602 is an input / output circuit including eight output ports and 16 input ports.

  The DIP switches 603-1 and 603-2 are DIP switches for setting transmission path information of the first USB port 604 and transmission path information of the second USB port 605, respectively. Each of the DIP switches 603-1 and 603-2 has the same configuration as the DIP switch 103 described in the embodiment, and each has eight switches.

  The FlashROM 104 stores setting information D2 (see FIG. 9).

  Next, an initial setting operation for the USB in the MFP 600 will be described. When the worker attaches the set of the relay cable 107-1 and the relay board P2-1 and the set of the relay cable 107-2 and the relay board P2-2, the configuration number (transmission path information) of each set is set. It reads from the transmission path configuration table F1 (see FIG. 7), sets the configuration number of the former set to the DIP switch 603-1, and sets the configuration number of the latter set to the DIP switch 603-2. Then, the worker instructs the CPU 101 to start the USB initial setting operation.

  The initial setting operation mainly operates as follows, as compared with the flow of the initial setting operation shown in the first modification (see FIG. 10). The CPU 101 of the multifunction peripheral 600 reads the transmission path information set in each of the DIP switches 603-1 and 603-2 through the I / O 602, and reads one of the signal voltage adjustment information corresponding to the transmission path information. It is set in the drive current value setting register of the USB host controller 102.

  Specifically, in step S11 (see FIG. 10), the CPU 101 reads an 8-bit configuration number set in the DIP switch 603-1 from the I / O 602. Further, the CPU 101 reads the 8-bit configuration number set in the DIP switch 603-2 from the I / O 602.

  Subsequently, in step S12 (see FIG. 10), the CPU 101 converts the setting range D2 (see FIG. 9) of the FlashROM 104 into the adjustment range and the propriety information of the adjustment range propriety information d3 corresponding to each component number read in step S11. Extract pairs.

  Then, in step S13 (see FIG. 10), the CPU 101 selects, from among the pairs, an adjustment width common to both of the adjustment ranges of “O / O” as the signal voltage adjustment information to be set in the setting register. For example, assume that the first configuration number read is “5” and the second configuration number is “3”. In this case, the adjustment ranges for which the availability information is “「 / ○ ”in the configuration number 5 are“ + 10% ”and“ + 20% ”. On the other hand, in the configuration number 3, the adjustment range in which the availability information is “に お い て / 構成” is “−10%”, “0%”, “+ 10%”, and “+ 20%”. The CPU 101 selects one of the adjustment widths suitable for both the configuration number 5 and the configuration number 3. In this example, since it is “+ 10%” and “+ 20%”, one of them is determined by a predetermined method. In this example, “+ 10%” is determined as the one with the lower increase rate.

  Subsequently, in step S14 (see FIG. 10), the CPU 101 sets the selected adjustment width in the drive current value setting register of the USB host controller 102 as signal voltage adjustment information. After the CPU 101 sets the setting register in step S14, the USB host controller 102 drives with the drive current value indicated by the adjustment width.

  In this example, an example in which two USB ports are provided and an example in which two DIP switches are provided are shown. However, the number of DIP switches is one because it is sufficient that each configuration number of a USB port can be set. May be.

  Similarly, in a device having three or more USB ports, a DIP switch is provided so that configuration numbers corresponding to the number of USB ports can be set. For example, DIP switches for the number of USB ports are provided, and these are connected to I / O. The CPU 101 selects one of the adjustment widths that matches all of the configuration numbers set in the DIP switch, and sets it as signal voltage adjustment information in a drive current value setting register.

  Further, in this example, the configuration in which the DIP switch is provided on the control board P1 has been described, but the DIP switch may be provided on the relay board P2 according to the configuration shown in the third modification. When a DIP switch is provided on the relay board P2, it is desirable to provide a DIP switch for each relay board P2.

  Further, the DIP switch may be provided in the relay cable according to the configuration shown in the fifth modification. Even when a DIP switch is provided on a relay cable, it is desirable to provide a DIP switch for each relay cable.

  When providing transmission line information to the relay board P2 or the relay cable, a ROM or an RFID tag storing the transmission path information is provided instead of the DIP switch, and the transmission path information is read by the control board P1. You may do it.

(Modification 7)
In a modified example 7 of the multifunction peripheral according to the embodiment, as another example of the multifunction peripheral having a plurality of signal transmission paths, the multifunction peripheral has a configuration in which a plurality of relay cables and a relay board are connected in series to one USB connection port. It shows about. Hereinafter, description overlapping with the embodiment will be appropriately omitted, and portions different from the embodiment will be described.

  The multifunction peripheral according to Modification 7 includes a first relay cable and a first relay board, and a second relay cable and a second relay board. The first relay cable and the first relay board, and the second relay cable and the second relay board are in this order, the first USB host connector 105 (see FIG. 2) and the second USB host connector 15 (see FIG. 2). 2) in series.

  The FlashROM 104 (see FIG. 2) stores setting information D20 (see FIG. 11).

  Next, the USB initial setting operation in the multifunction peripheral will be described. When the worker attaches the first relay cable and the first relay board, and the second relay cable and the second relay board, the configuration number (transmission number) of the configuration in which the respective cable lengths and pattern lengths are added. Path information) is read from the transmission path configuration table F20 (see FIG. 11), and the configuration number is set in the DIP switch 103 (see FIG. 2). Then, the worker instructs the CPU 101 (see FIG. 2) to start the USB initial setting operation. The CPU 101 reads the setting information D20 stored in the FlashROM 104 and performs the same operation as in the embodiment.

  In this example, as an example of a configuration in which a plurality of relay cables and a relay board are connected in series, a first relay cable and a first relay board, and a second relay cable and a second relay board are connected in series. Although an example of the configuration in the case where the connection is made is shown, the number of relay cables and relay boards may be arbitrary.

  Further, in this example, the configuration example in which one DIP switch is provided is shown, but a plurality of DIP switches may be provided corresponding to the number of relay cables. For example, in the above-described configuration in which the first relay cable and the first relay board and the second relay cable and the second relay board are connected in series, the first relay cable and the first relay board are connected to each other. A first DIP switch, a second relay cable, and a second DIP switch on a second relay board are provided. The operator reads the configuration number (transmission path information) of the first relay cable and the first relay board from the transmission path configuration table F20, and sets the configuration number in the first DIP switch. Further, the operator reads the configuration number (transmission path information) of the second relay cable and the second relay board from the transmission path configuration table F20, and sets the configuration number in the second DIP switch. In the USB initial setting operation, the CPU 101 reads the setting information having the adjustment width (see FIG. 9) of the Flash ROM 104, and sets the first DIP switch within the adjustment width in which the availability information becomes “○ / ○”. The configuration number which is common to the configuration number and the configuration number set in the second DIP switch is selected as signal voltage adjustment information to be set in the setting register.

  Further, in this example, the configuration in the case where the DIP switch is provided on the control board P1 (see FIG. 2) is shown, but the first relay cable connected in series, the first relay board, and the second relay board are connected. It may be provided on each of the cable and the second relay board. Further, for example, a combination of a relay cable and a relay board may be set, and a DIP switch may be provided on one of the sets.

  Further, the configuration is not limited to a configuration in which the setting can be changed like a DIP switch, and a configuration in which the setting is fixed to a constant value may be used.

  Further, when providing the transmission line information on the relay board or the relay cable, a ROM or an RFID tag storing the transmission line information is provided instead of the DIP switch, and the control line P1 reads the transmission line information. You may do it.

(Modification 8)
As a modified example 8 of the multifunction peripheral of the embodiment, a multifunction peripheral having a notification function of notifying a configuration error of an internal transmission path will be described. Hereinafter, description overlapping with the embodiment will be appropriately omitted, and portions different from the embodiment will be described.

  In the setting information D1 (see FIG. 7) shown in the embodiment, the signal number adjustment information d2 corresponding to the configuration number “7” and the configuration number “8” of the configuration number d1 are both “setting impossible”. That is, when the configuration of the internal transmission path is “7” and “8”, it indicates that there is no value that can be set, including the standard value. In such a case, the multifunction peripheral of Modification 8 stores the information of the notification screen in the FlashROM 104 to notify the operator that “setting is not possible” in such a case, and displays the notification screen on the screen of the display 14. Let it.

  A specific operation will be described based on an initial setting operation flow (see FIG. 8) of the embodiment. First, in step S1, the CPU 101 reads an 8-bit configuration number set by the DIP switch 103.

  Subsequently, in step S2, the CPU 101 extracts signal voltage adjustment information corresponding to the read configuration number from the setting information D1 of the FlashROM 104.

  Here, the CPU 101 determines whether or not the extracted signal voltage adjustment information is information indicating “setting impossible”. If the extracted signal voltage adjusting information is information indicating “setting impossible”, the CPU 101 displays the notification screen stored in the FlashROM 104. The information is displayed on the screen of the display 14 as a notification screen (see FIG. 17). Thereafter, when the notification screen is cleared, the process ends.

  Thereafter, it is assumed that the operator changes the configuration number of the DIP switch by replacing the relay cable with a short one, and starts the initial setting operation flow again. In this case, if the configuration after the change is not the configuration that cannot be set, the CPU 101 sequentially performs the processing of steps S1 to S3 and sets the signal voltage adjustment information in the drive current value setting register.

  FIG. 17 is a diagram illustrating an example of the notification screen displayed on the screen of the display 14. The notification screen H1 shown in FIG. 17 includes notification information h1 and an OK button h2. The notification information h1 is an area indicating message information that informs an operator that a relay cable or a relay board attached to the inside of the device has a configuration of “setting is impossible”. The notification information h1 prompts the operator to change the configuration, such as changing the length of the relay cable. The OK button h2 is an operation button for instructing the CPU 101 to end the initial setting program by a touch operation by an operator.

  In this example, the mode in which the notification screen H1 is output to the display 14 as a notification unit for notifying the operator that the relay cable or the relay board attached to the inside of the machine has a “setting impossible” configuration has been described. The means for notifying the worker is not limited to this. As long as it is known that the configuration is “setting impossible”, such as playing a voice message, sounding a buzzer, or turning on an optical element such as an LED, the configuration may be changed as appropriate.

  In the present embodiment and each of the modifications, the transmission path information indicating the configuration of the in-machine transmission path is the cable length of the relay cable, the pattern length of the relay board, or the like. However, the transmission path information is not limited thereto. The transmission line information may include, as appropriate, a factor that affects the impedance of the in-machine transmission line. For example, the material and thickness of the signal line of the relay cable, the width and thickness of the circuit pattern of the relay board, the distance between planes, the presence or absence of a common mode filter for EMI countermeasures, and the material of various connectors may be appropriately included. In that case, each configuration classified by each factor is set in the transmission path information configuration tables F1 and F20, and the corresponding signal voltage adjustment information is set in the setting information D1, the signal voltage adjustment information D2, and the setting information D20. .

  In the present embodiment and each of the modifications, the configuration in which the transmission path information is stored by setting the DIP switch has been described, but the transmission path information storage unit is not limited to this. For example, the transmission path information may be stored in a memory such as a FlashROM. The transmission path information may be stored in advance, or may be set in the memory when a relay cable or the like is connected.

  In the embodiments and the respective modifications, examples in which the communication device is applied to a multifunction peripheral have been described. In the embodiment and each modified example, the multifunction peripheral having the functions of the scanner and the printer is described. However, the multifunction peripheral having at least two functions of the copy function, the printer function, the scanner function, and the facsimile function can be applied. is there. Further, the present invention can be applied to any of image forming apparatuses such as a copier, a printer, a scanner, and a facsimile machine.

  The application to the multifunction peripheral is an example, and the communication device can be applied to other devices. For example, a device such as a USB that performs current-driven differential signal communication, such as an “image processing device” such as a projector or a video conference system, or a “mobile terminal” such as a mobile phone or a portable information terminal. , "Information processing device" and the like. Further, application to equipment mounted on a vehicle or the like is also possible.

  The programs executed in the embodiment and each modified example are provided to be incorporated in a memory unit such as a FlashROM in advance, but are not limited thereto. The program executed in the embodiment and each modified example may be recorded on a computer-readable recording medium and provided as a computer program product. For example, a file in an installable or executable format may be recorded on a recording medium such as a flexible disk, a CD-R, a DVD (Digital Versatile Disk), a Blu-ray Disc (registered trademark), or a semiconductor memory and provided. Good.

  Further, the program executed in the embodiment and each modified example may be stored on a computer connected to a network such as the Internet, and provided by being downloaded via the network. Further, the program executed in the embodiment and each modified example may be provided or distributed via a network such as the Internet.

  The initial setting program executed in the embodiment and each modification has a module configuration including a setting unit (the setting unit described above). As actual hardware, a CPU reads the program from the storage medium and executes the program. By doing so, the setting unit is loaded on the main storage device, and the setting unit is generated on the main storage device.

  The embodiment and the modified example of the present invention have been described above, but the embodiment and the modified example are presented as examples, and are not intended to limit the scope of the invention. These new embodiments and modifications can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modified examples are included in the scope and gist of the invention, and are included in the invention described in the claims and equivalents thereof.

15 second USB host connector 20 USB device connector 30 general-purpose USB cable 100 multifunction peripheral 101 CPU
102 USB host controller 103 DIP switch 104 FlashROM
105 first USB host connector 106 relay connector 107 relay cable 200 general-purpose USB device device P1 control board P2 relay board

Patent No. 4392407

Claims (9)

Transmission line information storage means for storing transmission line information indicating a configuration of a signal transmission line in the device;
Adjustment information storage means for storing a plurality of candidates for signal voltage adjustment information for keeping the amplitude level of the signal voltage at both ends of the signal transmission line in the machine within a predetermined range for each of the transmission line information,
Reading the transmission path information stored by the transmission path information storage means, and reading the transmission path information, the signal voltage adjustment information of one of the plurality of candidates stored by the adjustment information storage means; Setting means for setting
Signal output means for outputting a signal of a signal voltage corresponding to the signal voltage adjustment information set by the setting means to the signal transmission line,
A communication device comprising: Further, a reset instruction unit for instructing reset from the signal voltage adjustment information once set to other signal voltage adjustment information,
The setting means resets the signal voltage adjustment information once set to the signal voltage adjustment information instructed by the reset instruction means,
The communication device according to claim 1 . The signal transmission path in the aircraft is configured to include a relay cable,
The transmission path information storage means has the relay cable,
The setting unit reads the transmission line information from the transmission line information storage unit of the relay cable, and sets the signal voltage adjustment information stored in the read transmission line information by the adjustment information storage unit.
The communication apparatus according to claim 1 or 2. The signal transmission path in the machine is configured to further include a relay board,
The transmission path information storage means has the relay board,
The setting unit reads the transmission line information from the transmission line information storage unit of the relay board, and sets the signal voltage adjustment information stored by the adjustment information storage unit of the read transmission line information.
The communication device according to claim 3 . The relay cable,
A signal line for transmitting the signal output by the signal output means,
A signal line in which the setting unit reads the transmission line information from the transmission line information storage unit;
including,
The communication apparatus according to claim 3 or 4. Equipped with multiple signal transmission paths inside the aircraft,
The transmission line information storage unit stores transmission line information indicating a configuration of each of the plurality of signal transmission lines,
The setting unit includes a common signal voltage adjustment corresponding to each transmission line information stored by the transmission line information storage unit from among the plurality of candidates for each transmission line information stored by the adjustment information storage unit. Set information,
Communication apparatus according to any one of claims 1 to 5. Furthermore, when the setting unit reads the transmission line information, the signal voltage adjustment information corresponding to the read transmission line information is not included in the signal voltage adjustment information stored by the adjustment information storage unit. Providing a notification means for notifying an error in the case,
Communication apparatus according to any one of claims 1 to 6. A method for controlling a signal voltage amplitude level executed in a communication device,
The communication device,
Transmission line information storage means for storing transmission line information indicating a configuration of a signal transmission line in the device;
Adjustment information storage means for storing a plurality of candidates for signal voltage adjustment information for keeping the amplitude level of the signal voltage at both ends of the signal transmission line in the machine within a predetermined range for each of the transmission line information,
With
Reading the transmission path information stored by the transmission path information storage means, and reading the transmission path information, the signal voltage adjustment information of one of the plurality of candidates stored by the adjustment information storage means; Setting the
Outputting a signal of a signal voltage corresponding to the set signal voltage adjustment information to the signal transmission line;
A method for controlling a signal voltage amplitude level. Transmission line information storage means for storing transmission line information indicating a configuration of a signal transmission line in the device;
Adjustment information storage means for storing a plurality of candidates for signal voltage adjustment information for keeping the amplitude level of the signal voltage at both ends of the signal transmission line in the machine within a predetermined range for each of the transmission line information,
A setting register of the signal voltage adjustment information of the signal output means for outputting a signal of a signal voltage corresponding to the signal voltage adjustment information to the signal transmission path;
A computer having
Reading the transmission path information stored by the transmission path information storage means, and reading the transmission path information, the signal voltage adjustment information of one of the plurality of candidates stored by the adjustment information storage means; Setting means for setting in the setting register,
A program to function as

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