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Serial data format and protocol frames
The communication between the reader and connected host (terminal, PC etc.) is handled
according to a specified protocol. The protocol used is suitable for use on a data bus and
includes a bus address.
The reader only supports the extended protocol frame (not compatible with the simple
protocol frame of the SLG D10). When the host application sends a protocol frame, the
reader always responds with a protocol frame.
With data transfer via the asynchronous interface, the reader returns the requested data or a
status byte. The response contains the transferred control byte. If a bad protocol frame is
transferred, the reader does not respond.
Protocol frame
Table 4- 1
Host → reader
Byte
1
Content
STX
Default
0x02
Table 4- 2
Host ← reader
Byte
1
Content
STX
Default
0x02
Table 4- 3
Function
STX
ALENGTH
(n = 8...65535)
COM-ADR
CONTROL-BYTE
STATUS
RF290R
Configuration Manual, 09/2014, C79000-G8976-C377-01
2
3
MSB
LSB
ALENGTH
ALENGTH
-
-
2
3
MSB
LSB
ALENGTH
ALENGTH
-
-
Description of the protocol byte
Description
If the response protocol of the reader starts with the character STX (0x02), the
protocol frame has the extended protocol length. In this case, the protocol length
is specified by the 2-byte parameter ALENGTH.
Number of protocol bytes including STX, ALENGTH and CRC16
0..254 address of the device in bus mode
The reader can be addressed at any time using COM-ADR 255.
Defines the command that the reader is to execute.
Includes the status message or protocol data from or to the reader.
1)
4
5
COM-ADR
CONTROL-
BYTE
-
-
4
5
COM-
CONTRO
STATUS
ADR
L-BYTE
-
-
(6 ... (n-2))
(n-1)
(DATA)
LSB
CRC16
-
-
6
(7 ... (n-2))
(n-1)
(DATA)
LSB
CRC16
-
-
-
4
n
MSB
CRC16
-
n
MSB
CRC16
-
19
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