3 ] Basic Format Of Transmission Messages - Denso BHT-6000 User Manual

[ 3 ] Basic Format of Transmission Messages

Basically, the BHT-6000 transmits data as units of a file. First, it transmits a heading
text which includes the attribute information of a file (e.g., file name and the number of
data texts) to be transmitted. Following the heading text, it transmits the data text in
the file. A heading text and data text comprise a text.
In actual text transmission, the text is divided into several blocks, then a header,
terminator, serial number, receiver station's ID, and CRC-16 (Cyclic Redundancy Check)
are added to each block.
transmission blocks makes up one transmission message.
Shown below is an example of a transmission message formed with the BHT-Ir
protocol.
Heading
Text
text
D
L
E
D
L
Transmission
Message
E
D
L
E
In the above figure, DLE SOH, DLE STX and DLE ETX are text control characters as
described in [ 2 ] Control Characters. An ID denotes the ID number of the receiver
station, expressed by two bytes. A serial number is expressed by a five-digit decimal
number, starting from 00001 to 32767, and identifies data texts. For the CRC-16, refer
to [ 6 ] CRC.
You can use the control characters for expressing IDs serial numbers, or text data.
TIP
For DLEs, type DLE DLE per DLE.
This procedure forms a transmission block.
Data text 1
S I
Heading text
• O
H D
(2 bytes)
S I
Serial
number
• T
X D
(5 bytes)
I
S
Serial
T
• number
D
X
Data text 2
D
L •
E
D
Data text 1
L •
E
D
Data text 2
L
•
E
106
A set of
Data text n
E C
Transmission
T R
block
X C
E C
Transmission
T R
block
X C
E C
Transmission
T R
block
X C