问题
I'm having trouble with RFID cards. I have 2 distinct devices that read RFID. When I scan ANY card, I always get 2 values each. I tested with a commun usb card reader, FYI.
The IDs I get are:
Device 1 (same as USB reader) = 0006628180
Device 2 (The odd one) = 10109044
Beware that this is the same card. I have other examples if you want. I just need to know what to do to get the same ID from both devices.
回答1:
Right, I feel stupid.
But if you stumble upon this question, here's an answer:
The ID often comes with more info in a single number. In this particular case the last 2 bytes (16 bits) of the ID are the card number:
6628180 = [....] 0010 0011 0101 0100 -> you can get those in the Windows calculator if you switch it to programmer mode.
Some devices just straight place both codes in a single ID:
10109044 = [....] 0100 0000 0111 0100 -> we can confirm that they are not the same
However, if we slice the 5 last digits of the ID (in this case 101 - 09044), we get:
09044 = 0010 0011 0101 0100 -> the same as the 2 bytes stored in the first value.
The reading of ID is based according to Motorola cards definition. Hope it helps.
来源：https://stackoverflow.com/questions/27481383/rfid-one-tag-gives-two-different-ids-in-two-different-readers