RF290R
Configuration Manual, 09/2014, C79000-G8976-C377-01
19
Serial data format and protocol frames
4
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
2
3
4
5
(6 ... (n-2))
(n-1)
n
Content
STX
MSB
ALENGTH
LSB
ALENGTH
COM-ADR CONTROL-
BYTE
(DATA)
LSB
CRC16
MSB
CRC16
Default
0x02
-
-
-
-
-
-
-
Table 4- 2
Host ← reader
Byte
1
2
3
4
5
6
(7 ... (n-2))
(n-1)
n
Content
STX
MSB
ALENGTH
LSB
ALENGTH
COM-
ADR
CONTRO
L-BYTE
STATUS
(DATA)
LSB
CRC16
MSB
CRC16
Default
0x02
-
-
-
-
-
-
-
-
Table 4- 3
Description of the protocol byte
Function
Description
STX
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.
ALENGTH
(n = 8...65535)
Number of protocol bytes including STX, ALENGTH and CRC16
COM-ADR
0..254 address of the device in bus mode
The reader can be addressed at any time using COM-ADR 255.
CONTROL-BYTE Defines the command that the reader is to execute.
STATUS
1)
Includes the status message or protocol data from or to the reader.