
4. PROTOCOL A B-63322EN-1/01
-14-
4.1
MESSAGE FORMAT
The information (character-string) exchanged between the remote
buffer and host computer is called “message”. The general type of
message is shown as below:
Field
Byte
length
Abbreviation Meaning Remarks
Checksum 2 No It is used to indicate the lower 8 bits of binary sum of all
bytes from the command field to end code by two-digit
hexadecimal number (0 – 9 and A – F).
Transmit the MSB
before the LSB.
Command 3 No It is used to display the type of message (functions) and
to specify the operation and response of the partner.
Data 0 – n Yes It is the data part corresponding to a command.
Abbreviate it when a command without data part is used.
Details are described later.
SAT, SET, DAT, RTY
SDI, SDO
End code
(ETX)
1 No It indicates the end of message. Not transmit a code
which is the same as an end code to data part.
4.2
CODE SYSTEM
The communication codes between the remote buffer and host
computer are described below:
Field Command Code
Related
parameters
Checksum --- ISO/ASCII 5000#2
Command name --- ISO/ASCII 5000#2
DAT ISO/ASCII/EIA/Bin 0000#2Data part
Commands other
than DAT
ISO/ASCII 5000#2
ISO/ASCII 5000#2End code ---
CR/ETX 5000#3
Sum Command Data part
/
/
ETX
1 byte
Variable length (it can be omitted.)3 byte2 byte
Message