User's Manual

ACG HF Multi ISO RFID Reader V1.0
ACG Identification Technologies GmbH 44
12.2.1 STX
Start of transmission (02h)
12.2.2 Station ID
Unique ID of the station
00h: reserved for the bus master. Readers send response to this device ID.
FFh: Broadcast message. All devices will execute the command and send their
response.
12.2.3 Length
Length defines the length of the data block, including the flag byte, if binary protocol
version 2 is activated.
If length is set to zero, 256 data bytes are transmitted. The reader module only can
send 256 data bytes, but cannot receive commands with 256 bytes.
12.2.4 Flags
The flag byte gives additional information to the host.
Bit 3 – Bit 7 Bit 1 – Bit 2 Bit 0
RFU Leading Character Info Error State
Error State
If cleared, the command was processed successfully.
If Error State is set, an error occurred.
Leading Character Info
Bit 1 & 2 defines how to interpret the data in the binary frame.
Bit 2 Bit 1 Description
0 0 No leading character available, all values are hexadecimal.
0 1 The data contains one leading character.
1 0 All data bytes are characters.
1 1 RFU
12.2.5 Data
This part contains the command and the data. The command values are the same as
in ASCII protocol mode (‘x’, ‘s’, …) whereas data is transmitted in binary mode.
The length of the command block depends on the instruction.