OBID
®
classic-pro
Manual
ID CPR30.xx
FEIG ELECTRONIC GmbH
Page 16 of 126
H01114-0e-ID-B.docx
2.3.4. Timing Conditions
Block timeout:
Defines the time within the reader response can be expected by the host. The host block
timeout shall be set to value longer than the time configured in CFG1.TR-RESPONSE-
TIME.
Host Reader:
..
max. TR-RESPONSE-TIME
Host Reader:
.. .. ..
Character timeout:
Within one protocol, the characters have to follow each other in intervals of maximum
12 ms.
max. 12 ms
max. 12 ms
max. 12 ms
Host Reader:
Char n
Char n+1
Char n+2
..
2.3.5. CRC16 Calculation Algorithm for Protocol Frames
Polynom:
x
16
+ x
12
+ x
5
+ 1 (reversed)
CRC_POLYNOM = 0x8408;
Start Value:
0xFFFF
CRC_PRESET = 0xFFFF;
C-Example:
unsigned int crc = CRC_PRESET;
for (i = 0; i < cnt; i++) // cnt = number of protocol bytes without CRC
{
crc ^= DATA[i];
for (j = 0; j < 8; j++)
{
if (crc & 0x0001)
crc = (crc >> 1) ^ CRC_POLYNOM;
else
crc = (crc >> 1);
}
}
