NEC RS-232C - Manual (Page 2)

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4. Communication Format
The command packet consists of four parts, Header, Message, Check code and Delimiter.
Sequence of a typical procedure to control a monitor is as follows,
[A controller and a monitor, two-way communication composition figure]
4.1 Header block format (fixed length)
1
st
byte) SOH: Start of Header
ASCII SOH (01h)
Header Message Check Code Delimiter
Header Message Check code Delimiter
SOH
Reserved
'0'
Destination Source
Message
Type Message
Length
1
st
2
nd
3
rd
4
th
5
th
6
th
-7
th
Monitor Controller
Header Message Check Code Delimiter
Header Message Check Code Delimiter
Get Parameter
Get Parameter Reply
Header Message Check Code Delimiter
Set Parameter
Header Message Check Code Delimiter
Set Parameter Reply
Header Message Check Code Delimiter
Header Message Check Code Delimiter
Get Parameter Reply
Save Current Setting Command
Get Parameter
Header Message Check Code Delimiter
The controller sends command to
get a value from the monitor that
you want to change.
The monitor replies a current value
of the requested item.
The controller sends commands to
set an adjusted value.
The monitor replies to the
controller for confirmation.
The controller sends command to
get a value for confirmation.
The monitor replies an adjusted
value.
The controller requests to store
the adjusted value to the monitor.
Header Message Check Code Delimiter
Header Message Check Code Delimiter
Command
Command Reply
The control does not suitable for
above fixed protocol; use the
proper command for each control.
Please refer section 5.5 and
section 7 to 13.
The monitor replies a proper
message defined for each control.
Header Message Check Code Delimiter
Save Current Setting Command Reply
The monitor replies to the
controller for confirmation.