Serial Port Management Error Codes

NOTE

This topic describes only module-specific error codes. For details about universal error codes, see Universal Error Codes.

35700001 Abnormal Service

Error Message

Service error.

Description

An internal error occurs in the serial port communication service when a serial port communication API is called.

Possible Causes

1. The serial port communication service is not started.

2. An internal error occurs in the serial port communication service.

Solution

1. Check whether the serial port function of the device is normal.

2. Restart the device and try again.

35700002 Parameter Error

Error Message

Invalid parameter.

Description

The input parameter is invalid when the serial port communication API is called.

Possible Causes

1. The baud rate is not a positive integer.

2. The length of the written data is out of range.

3. The timeout interval is out of the range.

4. The parameter type is incorrect.

Solution

1. Check whether the baud rate is a positive integer.

2. Check whether the length of the written data is within the range of (0, 4096].

3. Check whether the timeout interval is within the range of [0, 300000].

4. Check whether the parameter types are correct.

35700003 Virtual Serial Port Disconnected

Error Message

Virtual serial port disconnected.

Description

When a serial port communication API is called, the USB virtual serial port device is disconnected.

Possible Causes

1. The USB-to-serial port cable is removed.

2. The USB virtual serial port is disconnected abnormally.

Solution

1. Check whether the USB-to-serial port cable is properly connected.

2. Remove and insert the USB device, call getSerialPortList to obtain the device list, and then call open to open the device.

35700004 Port in Use

Error Message

Port already in use.

Description

When the open API is called to open a serial port, the serial port has been occupied by another application or process.

Possible Causes

1. The same serial port is opened by another application.

2. The serial port is not properly disabled in the previous operation.

Solution

1. Close other applications that occupy the serial port.

2. Call close to close the serial port and then open it again.

35700005 Port Not Opened

Error Message

Port not open.

Description

The serial port is not opened when a serial port communication API is called.

Possible Causes

1. The open API is not called to open the serial port.

2. The serial port has been closed.

Solution

1. Call the open API to open the serial port.

2. Check whether the serial port is closed. If so, open it again.

35700006 Transmission Timeout

Error Message

Transmission timeout.

Description

Data transmission times out when the write API is called to write data.

Possible Causes

1. Data fails to be written to the serial port within the specified period.

2. The receiving device does not respond.

3. The serial port communication parameters do not match.

4. Data cannot be sent in time due to frequent write requests and congestion of the send buffer.

Solution

1. Check whether the receiving device is properly connected.

2. Increase the timeout interval.

3. Check whether the serial port communication parameters (such as the baud rate) are consistent with those of the peer end.

4. Reduce the write frequency or call the drain API between writes to wait until the previous data transmission is complete before sending new data.

35700007 User Authorization Rejected

Error Message

User authorization required.

Description

When the open API is called to open a serial port, the system checks whether the user has authorized the application to access the target serial port. If not, this error code is returned.

Possible Causes

1. The user rejects the application's request to access the target serial port in the authorization dialog box.

Solution

1. Instruct the user to allow the application to access the target serial port in the authorization dialog box.

35700008 Permission Denied

Error Message

Permission denied.

Description

The current application does not display a pop-up window for serial port authorization, so it does not have the permission to call the serial.addPortAuthorization API.

Possible Causes

1. The caller is not an application that displays a pop-up window for serial port authorization. The serial.addPortAuthorization API can be called only by applications that display a pop-up window for serial port authorization.

Solution

1. Check whether the current application is an application that displays a pop-up window for serial port authorization. This API can be called only by applications that display a pop-up window for serial port authorization.