Kathrein ARU4 Series, User Manual

Page: 39 / 122

39 of 122
11.3 Ethernet Transmission
A data transmission layer has been used for communication to our reader over Ethernet, just like in serial
communication.
The data transmission layer over Ethernet is a much more simple solution here since the TCP/IP protocol already has a
data security layer. As TCP/IP is a stream protocol, only the packet beginning and packet end are necessary.
There are 3 frame types in the protocol used in the Generation 3 readers.
If no data have been received for 100 milliseconds within a frame, the received part frame is dismissed. The payload (D1
to Dn) is identical to the Generation 2 payload.
11.3.1 Ethernet Transmission Generation 2 Readers
Frame Set-up
A frame looks as follows:
Start + data block + end
The start is made up of 0xAA 0xBB 0x01 0x01 , whereby the first 1 is the Datetransmit byte and the second 1 is a Stuffbyte. The
end is made up of 0xAA 0xCC . If the byte 0xAA appears in the KBRP frame, it must be doubled ( 0XAA 0xAA 0xAA ).
Port
The TCP communication port is the port 4007.
Example
The frame ASyncGetEPCs is shown here as an example. The ID for this command is 0x0111 , which makes the frame look as
follows:
0xAA 0xBB 0x01 0x01 0x11 0x01 0xAA 0xCC
Extended Block Structure
If a data block to be transmitted exceeds 16 kB, it is necessary to subdivide into several 16-kB blocks. These blocks
receive a block number, and the first block contains the total data length. It is necessary to confirm the reception of
each block by means of an answer.
First block:
Start + block number always 0 + 4-byte total data data block + end
All other blocks:
Start + block data block + end
Answer to confirm the reception:
Start + block end
The start consists of 0xAA 0xBB 0x0E 0x01 . The end consists of 0xAA 0xCC . If the 0xAA occurs in the KBRP frame, it is necessary
to double it:
0xAA
ൺ
0xAA 0xAA
.
11.3.2 Ethernet Transmission Generation 3 Readers
Frame Set-up
Data Frame
5A 50 L1 L2 L3 L4 D1 … Dn A5
5A start code
50 code for a data frame
L1 – L4 number of data bytes (D1 to Dn) in the data frame (32 bit; LSB first)