Waveshare RS232/485 TO WIFI POE ETH (B) User Manual page 44

RS232/485 TO WIFI POE ETH (B) User Manual
Length:
The sum of all bytes from the start of the function code to the checksum (excluding the
checksum). Note: The high byte comes first.
Function code:
Bit0：（UDP：0； TCP：1）
Bit1: (Long connection: 0)
Bit2：（IP：0； Domain name: 1)
Bit7: (Simplified Protocol: 0; Full Protocol: 1)
supported.
Note:
For Bit1, long connection, after sending data, the connection will be maintained until the target

address is changed again.
For Bit2, it represents whether the target address is IP or domain name, and if it is IP, the target

address is 4 bytes; If it is a domain name, the length of the target address is the length of the
entire domain name string (where the last byte of the target address is 0x00, that is, the end of
the string, and the length of the domain name is indefinite).
For Bit7, under the simplified protocol, the reply frame only contains data; Under the full

protocol, the reply frame will have frame formats such as sending failure, waiting timeout, and
responding device IP under UDP broadcast.
Reserved parameter area:
First byte: long connection, here 0x00.
Second byte: reserved
Target port:
Little-endian format, with the low byte first. For example, the port number 33 would be
represented here as 2100.
Target address:
If it is IP, it is 4 bytes, for example, 192.168.0.133 means 8500A8C0; If it is a domain name, the
length of the address is uncertain, ending with '\0'.
Data:
The length is variable, and the maximum is 4*1024 bytes.
Checksum:
Note: Only long connections are supported at present.
Note: Currently, only the simplified protocol is
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