Example System Default Card Format HID 35bitsTotal Bit Length: 35 Facility Code: 3522 Facility Code Start Bit: 3 Facility Code Length: 12 Card Number Start Bit: 15 Card Number Length: 20 This Format will only allow us to use card number from 1-1048575 Because the card number bit length is only 20bits if you open a calculator and convert 1048575 to binary this will be the result in binary is 11111 11111 11111 11111 If we change the same format Total Bit Length: 35 Facility Code: 35 Facility Code Start Bit: 3 Facility Code Length: 7 Card Number Start Bit: 10 Card Number Length: 25 This Format will only allow us to use card number from 1-3355443 Because we increase the amount of bits for the card number section. More to come |