RFID data format: RDM6300 vs EM4100 readers

Hi Everyone,

I have bought a few RDM6300 RFID readers. I can read the RFID token, no problem.

Reader similar to mine: http://www.ebay.com/itm/125K-RFID-rdm6300-ID-RF-UART-for-Arduino-Open-Source-Reset-Button-D13-LED-5cm-/301036583316?pt=LH_DefaultDomain_0&hash=item46172db994

Token used: http://www.ebay.com/itm/10pcs-EM4305-125Khz-Writable-Rewrite-RFID-Tokens-Blank-Card-/281077227315?pt=LH_DefaultDomain_0&hash=item4171821f33

I was able to write some code to "learn" some token, use them, etc...

Next step, was to generate a database in my PC that could use those tags as well. I bought the following USB reader (EM4100):


Once connected, it will read my token, no problem.

The problem is that the value read from one reader DOES NOT correspond to the other. Example:

Token labelled "0006547886"
USB reader reads "0006547886"
Arduino reader reads: 2,48,49,48,48,54,51,69,57,65,69,50,53,3
2 seems to be some sort of header, the next 10 digits are the ASCII value, followed by the "checksum (2 digit) and the last digit is the "footer"
ASCII value is then : 010063E9AE

Checksum = (01h) XOR (00h) XOR (63h) XOR (E9h) XOR (AEh)

Anybody has an idea on how to relate 0006547886 to 010063E9AE ?????

I'm totally lost !

More info about the RDM6300 reader: http://www.seeedstudio.com/wiki/125Khz_RFID_module_-_UART

The token value 6547886 when expressed in hexadecimal is 63E9AE
That is very close to what you see.
Often different manufacturers readers produce different codes with the same token as a way ensuring that all there readers are used in any one installation.

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So simple…

Sometime, when you’re too close to the trees, you no longer see the forest …

Thanks !

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