Is there an agreement for transmitting part numbers through the serial port?

Question

I have some devices that read the RFID tag and transmit the serial number of the tag through the serial port.

It seems to me that it’s “better” to use two bytes for each digit of the serial number, especially since some devices send a trailing 0x0D 0xA (CR / LF).

Now I find one device that uses one byte per digit, so for sending "12" it does not send 0x31, 0x32, but rather 0x12. This means that I cannot distinguish between CR / LF and real 0xA and 0xD. I ask and get some waffles about it no matter how fixed-length strings - so why bother with CR LF? And, to be consistent, they use two bytes for CR / LF.

As you could put together, I am pretty new to this project and somewhat confused by the discrepancies between devices from different manufacturers.

The manufacturer of this will happily change his firmware to suit me. Should I ask them to use two bytes for each digit?

Answer 1

- , . , / . - . - : STARTBYTE, DATA, CHECKSUM sumtimes ~ CHECKSUM ( ) , , STOPBYTE. , , .

. . , CR/LF . , CR LF , . , . , , , ( ). . - . 0xFF 0x00 DATA0 DATA1 0xFF. 2 -. , . 0xFF 0x00 0xFF . , .

, CR/LF , , , RFID, CR/LF .

, , - . , .

• -

, , .

Answer 2

, , - , . ( , 256 ) .