Connection Problem of Serial Device Server: After serial device server establishing connection, the server receives the unknown character
After the connection is established, the device sends unknown characters to the server. Reasons: Maybe use Telnet to use Telnet protocol (This phenomenon will only exist in the old firmware, which is the firmware version <2008, this problem does not exist in 2008 and later firmware.)
Module Id type
Solution: Select RAW; ID type is set to 0.