Feig Electronic ID ISC.LRU3000, Руководство пользователя

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OBID i-scan
®
UHF Manual ID ISC.LRU3000/3500
FEIG ELECTRONIC GmbH Page 21 of 193 H90202-7e-ID-B.docx
Data format:
Start bits: 1
Data bits: 8
Stop bits: 1
Parity:
even (default)
odd
none
Timing conditions:
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 ..
6.3. CRC16 Calculation Algorithm
Polynomial: 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);
}
}