OBID i-scan
®
System-Manual
ID ISC.MR200
FEIG ELECTRONIC GmbH
Page 19 of 144
H40801-5e-ID-B.doc
2.2. Serial Data Format and Protocol Frames
The Reader ID ISC.MR200-A can be configured can be configured by different interfaces and data
may be written on Transponders or read from Transponders. The communication between Reader and
connected host (terminal, PC, etc.) is executed by means of fixed protocols. The used protocol is in-
tended for data bus use and is equipped with a bus address.
During data transfer via the asynchronous interface the Reader supplies the required data or a status
byte. The reply contains the transmitted control byte.
There is no reply from the Reader if there is a protocol frame failure.
Protocol frame: Standard Protocol-Length (up to 255 Byte)
Host
→
Reader
1
2
3
4...n-2
n-1
n
LENGTH =
n
COM-ADR
CONTROL-
BYTE
(DATA)
LSB
CRC16
MSB
CRC16
Host
←
Reader
1
2
3
4
(5...n-2)
n-1
n
LENGTH
(n)
COM-ADR
CONTROL-
BYTE
STATUS
(DATA)
LSB
CRC16
MSB
CRC16
Protocol frame: Advanced Protocol-Length
Reader
←
Host
1
2
3
4
5
(6...n-2)
STX
(0x02)
MSB
ALENGTH
LSB
ALENGTH
COM-ADR
CONTROL-
BYTE
(DATA)
©
n-1
n
ª
LSB
CRC16
MSB
CRC16
Host
←
Reader
1
2
3
4
5
6
(7...n-2)
STX
(0x02)
MSB
ALENGTH
LSB
ALENGTH
COM-ADR
CONTROL-
BYTE
STATUS
(DATA)
©
n-1
n
ª
LSB
CRC16
MSB
CRC16