Feig Electronic ID ISC.MU02.02-CU, Руководство пользователя

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OBID i-scan
®
UHF Manual ID ISC.MU02.02
FEIG ELECTRONIC GmbH Page 18 of 96 H90701-3e-ID-B
Data format:
Start bits:
1
Data bits:
8
Stop bits: 1
Parity: even (default)
odd
none
Data timeout:
Within one protocol, the characters have to follow each other in intervals of max-
imum 12 ms.

max. 12 ms
 
max. 12 ms
 
max. 12 ms

Host
→
Reader:
Char n Char n+1 Char n+2 ..
6.2. CRC16 Calculation Algorithm
Polynom: x
16
+ x
12
+ x
5
+ 1
⇒
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);
}
}