How to Manage Serial Port Disconnections in Application Development: Difference between revisions
No edit summary |
No edit summary |
||
Line 1: | Line 1: | ||
== Issue Identification: == | |||
During the operation of an application that reads from a serial port, if an error message stating "Level 3 halted" appears in the log, it typically indicates that the serial port cable has been disconnected. | |||
== Recommended Solution: == | |||
# '''Immediate Action upon Error Detection:''' | |||
#* Upon encountering this error, the application should immediately close the serial port. | |||
# '''Attempt to Reopen the Serial Port:''' | |||
#* After closing, the application should try to reopen the serial port. | |||
# '''Handling Persistent Connection Issues:''' | |||
#* If the application fails to reopen the serial port, check and reconnect the serial port cable as necessary. | |||
== Java SDK Implementation: == | |||
* '''Catching DeviceException during Serial Port Read:''' | |||
** In the Java SDK, you can handle this situation by catching the DeviceException when performing serial port read operations. | |||
== Code Snippet Example: == | |||
<syntaxhighlight lang="java"> | <syntaxhighlight lang="java"> | ||
try { | try { | ||
Line 18: | Line 28: | ||
} | } | ||
</syntaxhighlight > | </syntaxhighlight > | ||
This approach ensures the application can effectively manage unexpected disconnections and attempts to re-establish the serial port connection. |
Revision as of 21:41, 24 December 2023
Issue Identification:
During the operation of an application that reads from a serial port, if an error message stating "Level 3 halted" appears in the log, it typically indicates that the serial port cable has been disconnected.
Recommended Solution:
- Immediate Action upon Error Detection:
- Upon encountering this error, the application should immediately close the serial port.
- Attempt to Reopen the Serial Port:
- After closing, the application should try to reopen the serial port.
- Handling Persistent Connection Issues:
- If the application fails to reopen the serial port, check and reconnect the serial port cable as necessary.
Java SDK Implementation:
- Catching DeviceException during Serial Port Read:
- In the Java SDK, you can handle this situation by catching the DeviceException when performing serial port read operations.
Code Snippet Example:
try {
byte[] readBytes = new byte[256];
SerialPortOperationResult serialPortOperationResult = serialPortDevice.waitForRead(readBytes.length, TimeConstants.FOREVER);
int resultCode = serialPortOperationResult.getResultCode();
if (resultCode == SerialPortOperationResult.SUCCESS) {
byte[] data = serialPortOperationResult.getData();
Logger.debug("read success:" + new String(data));
} else if (resultCode == SerialPortOperationResult.LEVEL_3_HALTED) {
Logger.debug("devices is gone, please close it first, then open it again.");
serialPortDevice.close();
}
} catch (DeviceException e) {
e.printStackTrace();
}
This approach ensures the application can effectively manage unexpected disconnections and attempts to re-establish the serial port connection.