OBID
®
classic-pro
Manual
ID CPR30.xx
FEIG ELECTRONIC GmbH
Page 15 of 126
H01114-0e-ID-B.docx
2.3.3. Protocol Elements
LENGTH (n = 6...255):
Number of protocol bytes including LENGTH and CRC16.
COM-ADR:
0...254 address of device in bus mode
NOTICE:
The Reader can be addressed via COM-ADR 255 at any time if a RS232/485 interface
is available!
COMMAND-BYTE:
Defines the Command which the Reader should operate.
STATUS
1
:
Includes the status message or protocol data from or to the Reader.
DATA:
Is an optional data field with variable length. The number of DATA byte depends on the
command. The data will be sent always as MSB first if the Reader is in the ISO-Host Com-
mand Mode.
CRC16:
Cyclic redundancy check of the protocol bytes from 1 to n-2, as specified by CCITT-CRC16
Polynom
0x8408 (x
16
+ x
12
+ x
5
+ 1 reversed)
Start Value
0xFFFF
In case of USB communication the CRC16 value is not checked by the reader.
STX:
The STX sign (0x02) at the start of protocol indicates an Advanced Protocol-Frame.
ALENGTH (n = 8...65535):
Number of protocol bytes including STX, ALENGTH and CRC16
Data format:
Start bits:
1
Data bits:
8
Stop bits:
1
Parity:
even (default)
odd
none
1
