I work with the RDM630 UART (RFID Reader) Module.
I have a problem, I can’t create the received checksums.
e.g. received date: 02 | 30 32 30 30 34 44 42 30 30 35 | 46 43 | 03
start | 10 ascii characters | checksum | end specified in spec
decoded hex date | 02h 00h 4Dh B0h 05h | FCh
when I do the xor Operation on the 5 bytes, I get 02 XOR 00 XOR 4d XOR b0 XOR 05 = FAh
wheres the fault?
Thanks for your help.
Yeah , it is very strange , I test a card , but work right . Other cards have the same problem to your RDM630?
e.g. received date: 02 | 30 31 30 30 30 37 33 34 45 30|44 32| 03
start | 10 ascii characters | checksum | end specified in spec
CardNumber Decimal: 48 49 48 48 48 55 51 52 69 48
CheckSum Decimal: 68 50
Refer to ASCII table,get Ascill value.
CardNumber Ascill value: 0 1 0 0 0 7 3 4 E 0
CheckSum Ascill value: D 2
(01H) xor (00H) xor (07H) xor (34H) xor (E0H) = D2H
Yes, I tested further tags and get the following answers:
card 1: 30 36 30 30 37 35 45 41 36 44 | 44 36
decoded 06h 00h 75h eah 6dh -> d6h
calculated checksum f4
card 2: 30 36 30 30 37 35 38 32 34 45 | 3B 44
decoded 06h 00h 75h 82h 4eh -> ??? here ascii translates “;D”
Where does the value 3b -> “;” comes from?
Where could be the fault? I dont think its a transmission fault - the values are still the same in nearly 100 transmissions.
Thanks for your help.
sorry i mentioned the wrong module - its a RDM6300 UART module that causes the faults.