Balluff BIS M-370-000-A02, Manual, Page: 183 / 198

BIS M-62_ MANUAL
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10
Bit 7
is always 1, to conform to Balluff’s proprietary Protocol.
Byte 1 : is always 0.
Byte 2 : contains the length of the packet in bytes (CBx Command or Command Fragment) to
be sent to the RFID Controller. This can be the length of an entire CBx command, or the
length of a fragment of a command, if the CBx command is larger than the space allowed to
send it in a single fragment.
Byte 3 through Byte N-2 are used for the actual CBx Command or Command Fragment to
be sent.
Byte N-1: the final byte of the Output Buffer is the Data Consistency Byte. It is a copy of
the Ouptut Buffer Control Byte. When changes to the Control Byte are made, the same
changes must
also be made in the Data Consistency Byte, before the changes “take effect”.
This is to guarantee the validity of the data between the two bytes.
The
INPUT Buffer is controlled by the Slave (RFID Controller) and is mapped the same way,
except for the packet bytes containing a response (or response fragment) from the controller.
Input Buffer
Byte #
00: INPUT BUFFER CONTROL BYTE (IBCB)
01: (Always 0)
02: Packet Length in Bytes
03:
04:
05:
06:
07:
08:
09:
10:
-
-
N-2: Packet Bytes (Response)
“ “
“ “
“ “
“ “
“ “
“ “
“ “
“ “
“ “
“ “
N-1: Data Consistency Byte (IBDCB)
Byte 0 is the Input Buffer Control Byte. The Slave uses the lowest four bits of this byte for
handshaking: to acknowledge receiving a command from the master (Bit 1), and to signal
that a response is ready for the master (Bit 0).
INPUT BUFFER CONTROL BYTE
7 6 5 4 3 2 1 0
[1]
[0] [0] [0]
[0] [0] [0] [0]
Bit 0 is toggled by the Slave when it has a new packet (response or response fragment)
ready for the Master.
Bit 1
is toggled by the Slave to acknowledge a packet (command or command fragment)
from the Master.