JP2005182380A - Recording device, electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a problem that the selection of a rapid communication mode may result in the increased occurrence of communication errors, in data communication control between a host computer and an electronic device of recording device or the like. <P>SOLUTION: The recording device performs communication with the host computer through an interface having a first and second communication modes of different communication speeds. The recording device is provided with a selection means for selecting the first or second communication mode, a calculation means for calculating communication quality with the host computer, and an output means for outputting the calculation result to a host device. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to data communication control between a host computer and an electronic device such as a recording apparatus.

  For example, when a USB used for data communication between a host computer and an electronic device is taken as an example, the USB 1.0 standard or the USB 1.1 standard has an LS mode (1.2 Mbps) and an FS mode (12 Mbps). The mode possessed by the hardware is set by a resistor attached to the communication line (D +, D−), and communication is performed in any mode.

  In recent years, with the aim of improving the communication speed, the USB 2.0 standard has dramatically improved the communication speed by providing an HS mode (480 Mbps) in addition to the LS mode and the FS mode.

When the host computer has the HS mode, the host computer generates a special signal during the bus reset, and it is determined by hardware whether or not the recording device has the HS mode based on the presence or absence of a response from the recording device. If it is determined that the recording apparatus side has the HS mode, communication is performed in the HS mode thereafter.
JP 2002-141808 A

  However, as can be seen from the description of the conventional example, when both the host computer and the electronic device (recording apparatus) have the HS mode, the communication in the HS mode is selected in hardware, and there are the following problems.

  Since the HS mode is a high speed of 480 Mbps, the design is more difficult than the FS mode / LS mode, and the occurrence of errors due to the environment such as cables may increase.

  In the initial stage of introduction of the HS mode, verification of driver software or the like corresponding to the HS mode may not be sufficient depending on the USB control chip.

  In the initial stage of HS mode introduction, compatibility testing may not be sufficient because there are few corresponding host computers and peripheral devices.

  In such a case, the USB is provided with a correction means for retransmitting data in order to prevent a malfunction due to a communication error, so that there is a problem of increasing the load on the host computer without the user's knowledge.

  In order to solve the above-described problems and achieve the object, an electronic device of the present invention is an electronic device that communicates with a host device via an interface having first and second communication modes having different communication speeds. A selection means for selecting the first communication mode and the second communication mode, a calculation means for calculating the host computer and communication quality, and a calculation result calculated by the calculation means for the host device. Output means for outputting.

  As described above, by notifying the host computer of the error rate detected by performing data communication between the host computer and the electronic device, it becomes possible for the user to determine the communication quality, and more stable data. Communication can be performed.

(First embodiment)
FIG. 1 is a schematic diagram including a USB communication unit 1 mounted on an electronic device (for example, a recording device), and has an FS mode (full speed mode) and an HS mode (high speed mode). The CPU controls the entire electronic device.

  The FS control unit is a control unit for performing communication at 12 Mbps, and performs data communication via B1 and B2. The HS control unit is a control unit for performing communication at 480 Mbps, and performs data communication via B3 and B4. The RPU is a pull-up resistor for allowing the host computer to recognize that the USB communication unit mounted in the recording apparatus has the FS mode, and can be turned on / off by B5.

  The error detection unit is a detection unit for detecting that an error has occurred in the received data from the host computer, the retransmission detection unit is a detection unit for detecting that there is a data retransmission request from the host computer, and the AMP is A differential amplifier VBUS for detecting differential reception data from the host computer is a + 5v input from the host computer and is used as an operation power source or a signal for detecting that the host computer is connected.

  The counter is a counter for counting the output from the error detection unit and the signal from the retransmission detection unit, and the HS prohibition unit is for prohibiting the USB communication unit from operating in the HS mode. is there.

  FIG. 2 is a diagram illustrating a procedure for determining whether the USB communication unit should operate in the FS mode or the HS mode.

  That is, after confirming the BUSRESET state on the recording apparatus side, in FIG. 2A, the recording apparatus side drives D− (K state in the figure), the host side drives D−, and D + is driven (J state in the figure) alternately. By repeating, it is confirmed that the recording apparatus side and the host side have the HS mode, and then the mode is switched to the HS mode.

  In FIG. 2B, the printing apparatus side drives D- (K state in the figure), but since the host side does not have the HS mode, it does not drive anything and operates in the FS mode.

  That is, as is apparent from this procedure, when both the recording apparatus and the host computer have the HS mode, they always operate in the HS mode.

  However, there are cases where sufficient stability cannot be ensured in the HS mode, which is the high-speed communication mode, as described in the problem of the conventional example.

  Therefore, a procedure for solving this problem according to the present invention will be described with reference to FIG.

  S1 After completing the cable connection, the BUSRESET state is set.

  S2 As described above, it is determined whether the mode is the HS mode or the FS mode, and the operation mode is set.

  The HS mode is set in S21, and the FS mode is set in S22.

  S3 Data communication necessary for the initialization operation required between the host computer and the recording apparatus is performed. In S31, it is determined whether or not the data communication is completed. If the necessary communication is not established, the process proceeds to S4. If communication has been completed even if an error has occurred, the process proceeds to S5.

  S4 Since the communication could not be performed, an error rate of 100% is set.

S5 Since communication is performed in units of packets, an error rate is obtained and set from the number of valid data transfers and the number of error transfers.
Error rate = number of valid data transfers / (number of valid data transfers and number of error transfers)
This is obtained from the number of effective data transfers at the time of data reception by the recording device and the number of times retransmission is requested due to the occurrence of a reception error (number of error transfers), etc. Calculate from the number of executions.

  Further, the number of occurrences of errors such as CRC errors may be counted during reception.

  Next, a determination is made based on a predetermined criterion (for example, an error rate of 50%) in S6. If the error rate obtained in S5 is equal to or less than the set value (50%), the process proceeds to S8, and if it is equal to or greater than the set value (50%), the process proceeds to S61.

S61 Since it is judged that there are many errors, the operation in the HS mode is prohibited (that is, the operation is possible only in the FS mode).
S7 BUSRESET is generated, and S2 and subsequent steps are repeated.

  S8: The first occurrence error rate and the current operation mode are notified from the recording device to the host computer.

  As described above, when the error rate is lower than the set value, the operation (communication) is performed in the HS mode, and when it is higher than the set value, the operation is switched to the FS mode. Can be obtained.

  FIG. 4 is an example of a screen for confirming the communication status with the recording device on the host computer, and 41 in FIG. 4 shows the communication status in the “error rate 1%, HS mode”.

  If the error rate is 60%, the display of the communication status changes to “error rate 60%, FS mode”.

  In the present invention, the operation after S1 can be repeated again by detecting the VBUS (that is, releasing the connection) and releasing the “HS mode prohibited” state.

  In this example, the communication mode can be switched depending on the error rate. On the communication status screen of FIG. 4 described above, a communication button for switching the communication mode, such as 42, is provided and a screen for displaying the setting status is provided. Make settings available on the computer. As an example, the high-speed mode is selected, but it is also possible to switch to the low-speed mode by clicking “low-speed mode” 42 in this screen.

  This screen is an example, and a setting button and a status display unit may be provided separately on the screen.

  By notifying the recording apparatus in S3, the user can select the FS mode regardless of the error rate, and a more stable operation can be performed. The recording device can stably receive the recording data from the host device and can execute the recording operation satisfactorily.

  The recording apparatus is, for example, an ink jet recording apparatus that performs recording by scanning (reciprocating) a recording head with respect to a recording sheet.

  Needless to say, the “HS mode prohibition” function is provided in the recording apparatus and can be set by the user.

(Other embodiments)
In this example, the USB interface has been described as an example. However, in other interfaces, for example, an interface based on IEEE1394, a plurality of data transfer speeds such as 400 Mbps, 200 Mbps, and 100 Mbps can be switched, and thus the present invention can be applied. .

  The screen described with reference to FIG. 4 is not necessarily independent, and may be displayed as one of the display items on the screen for displaying the operation state of the printer, for example.

  Further, as an example of the electronic apparatus, a printer that receives data (command, recording data) sent from a host device, discharges ink from a recording head, and records on a recording medium such as recording paper has been described as an example. It is not limited to a printer, and may be an image input device such as a scanner, a digital camera, or a portable device.

The figure for demonstrating the communication part of the recording device by this invention The figure for demonstrating the operation | movement in 1st Embodiment. The figure for demonstrating the operation | movement procedure in 1st Embodiment. The figure which shows an example which displays the communication state in 1st Embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 USB communication part 2 Reception error detection part 3 Retransmission detection part 4 Error and retransmission number counter 5 HS mode prohibition setting part

Claims (5)

A recording device that communicates with a host device via an interface having first and second communication modes having different communication speeds,
Selecting means for selecting the first communication mode and the second communication mode;
Calculating means for calculating communication quality with the host computer;
An output unit that outputs a calculation result calculated by the calculation unit to the host device.   The recording apparatus according to claim 1, wherein the host device outputs the calculation result.   3. The recording apparatus according to claim 1, wherein a selection signal for selecting the first and second communication modes is output from the host apparatus to the recording apparatus.   The recording apparatus according to claim 1, wherein a communication mode is switched by inputting the selection signal. An electronic device that communicates with a host device via an interface having first and second communication modes having different communication speeds,
Selecting means for selecting the first communication mode and the second communication mode;
Calculating means for calculating communication quality with the host computer;
An electronic device comprising: output means for outputting a calculation result calculated by the calculation means to the host device.

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