# USB Error Codes > **NOTE** > > This topic describes only module-specific error codes. For details about universal error codes, see [Universal Error Codes](../errorcode-universal.md). ## 14400001 USB Device Connection Denied **Error Message** Access right denied. Call requestRight to get the USBDevicePipe access right first. **Description** This error code is reported if a certain API of the USB module is called but the required permission is not granted. **Possible Causes** The permission to access the USB device is not granted. **Solution** Call **requestRight** to request for the permission to access the USB device. ## 14400002 HDC Disabled **Error Message** Permission denied. The HDC is disabled by the system. **Description** This error code is reported if HDC is disabled by the system. **Possible Causes** The USB debugging permission is not granted. **Solution** Apply for the USB debugging permission. ## 14400003 Port Role Switching Unsupported **Error Message** Unsupported operation. The current device does not support port role switching. **Description** This error code is reported if the port role is switched. **Possible Causes** The port role is incorrect. **Solution** Use the correct port role. ## 14400004 Service Exception **Error Message** Service exception. Possible causes: No accessory is plugged in. **Description** This error code is reported if the service is abnormal. **Possible Causes** No accessory is inserted. **Solution** Insert the accessory. ## 14400005 Database Operation Exception **Error Message** Database operation exception. **Description** This error code is reported if the database operation is abnormal. **Solution** Call the API again. ## 14400006 USB Device Function Unsupported **Error Message** Unsupported operation. The function is not supported. **Description** This error code is reported if the unsupported USB device function is used. **Possible Causes** The USB device function is not supported. **Solution** Use the correct USB device function. ## 14401001 Target USB Accessory Unmatched **Error Message** The target USBAccessory not matched. **Description** This error code is reported if the target USB accessory does not match the device. **Solution** Call **getAccessoryList** to obtain the accessory list and use a matched USB accessory to try again. ## 14401002 Failed to Open the Native Accessory Node **Error Message** Failed to open the native accessory node. **Description** This error code is reported if the attempt to open the native accessory node fails. **Solution** Call the API again. ## 14401003 Accessory Opened Repeatedly **Error Message** Cannot reopen the accessory. **Description** This error code is reported if an accessory is opened repeatedly. **Solution** The accessory has been opened. Continue to perform subsequent operations. ## 14400007 Resource Busy **Error Message** Resource busy. Possible causes: 1. The transfer has already been submitted. 2. The interface is claimed by another program or driver. **Description** This error code is reported if the requested resource is in use. **Possible Causes** 1. The transmission task has been submitted. 2. The API is occupied by another program or driver. **Solution** Check whether [usbManager.claimInterface](js-apis-usbManager.md#usbmanagerclaiminterface) is successfully called. ## 14400008 No Device (Disconnected) **Error Message** No such device (it may have been disconnected). **Description** This error code is reported if the device cannot be identified. **Solution** Check whether the device type is correct and whether the device is successfully connected. ## 14400009 Insufficient Memory **Error Message** Insufficient memory. Possible causes: 1. Memory allocation failed. **Description** This error code is reported if no memory is available when being requested. The maximum data size is 1 KB for a single transfer. **Possible Causes** The memory usage is too high to allocate sufficient space to the current task. **Solution** Clear memory in a timely manner. ## 14400010 Unrecognized Error **Error Message** Other USB error. Possible causes: Unrecognized discard error code. **Description** This error code is reported if an unknown error occurs. **Solution** Correct the error by referring to the related documentation, and try again. ## 14400011 No Ongoing Transfer Found **Error Message** The transfer is not in progress, or is already complete or cancelled. **Description** This error code is reported if the current data transfer has been canceled or completed. **Solution** Initiate a new data transfer request. ## 14400012 I/O Error **Error Message** Transmission I/O error. **Description** This error code is reported when the read/write operation fails due to the abnormal I/O channel. **Solution** Try again. ## 14400013 Parameter Validity Check Failed **Error Message** The USBDevicePipe validity check failed. Possible causes: 1. The input parameters fail the validation check. 2. The call chain used to obtain the input parameters is not reasonable. **Description** This error code is reported if the parameter validity check fails. **Possible Causes** 1. The validity check of the input parameter fails. 2. The input parameter call chain is improper. **Solution** Use a proper call chain to obtain the input parameter. ## 31400001 Serial Port Service Error **Error Message** Serial port management exception. **Description** This error code is reported if the serial port service is abnormal. **Possible Causes** The process exits due to a program exception. **Solution** Check whether the device is connected, and obtain the correct serial port number from the serial port list. ## 31400002 No Serial Port Device Access Permission **Error Message** Access denied. Call requestSerialRight to request user authorization first. **Description** This error code is reported if you do not have the permission to access the serial port device. **Possible Causes** You have not applied for the permission to access the serial port device. **Solution** Call **requestSerialRight** to apply for the access permission. ## 31400003 Port Number Not Exist **Error Message** PortId does not exist. **Description** This error code is reported if the port number does not exist. **Possible Causes** The original port number becomes invalid because the device connection is abnormal. **Solution** Remove and insert the device, and try again. ## 31400004 Port in Use **Error Message** The serial port device is occupied. **Description** This error code is reported if the serial port device is occupied. **Possible Causes** The serial port device is enabled repeatedly. **Solution** Remove and insert the device, and try again. ## 31400005 Device Not Opened **Error Message** The serial port device is not opened. Call the open API first. **Description** This error code is reported if the serial port device is not opened. **Possible Causes** A device has not been opened. **Solution** Call the **Open** API to open the device before performing subsequent operations. ## 31400006 Data Transfer Timeout **Error Message** Data transfer timed out. **Description** This error code is reported if data transfer times out. **Possible Causes** The peer end does not send data. **Solution** Check whether the peer device initiates data transfer. ## 31400007 I/O Exception **Error Message** I/O exception.Possible causes: 1. The transfer was canceled. 2. The device offered more data than allowed. **Description** This error code is reported if an I/O exception occurs. **Possible Causes** 1. The transfer task is canceled abnormally. 2. The amount of received data in a single transfer exceeds the buffer size limit. **Solution** Adjust the buffer size properly, and perform data transfer again.