NEC RS-232C Car Video System User Manual


 
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4. Communication Format
The command packet consists of four parts, Header, Message, Check code and Delimiter.
Recommended sequence of a typical procedure to control a monitor is as follows,
[A controller and a monitor, two-way communication composition figure]
For the general command (see the part "6.3. Operation Code (OP code) Table)
For the special command (see the part 7 to 14. and 5.5.2)
Header Message Check Code Delimiter
Monitor Controller
Header
Message
Check Code
Delimiter
Get Parameter
Get Parameter Reply
Set Parameter
Set Parameter Reply
Get Parameter Reply
Save Current Setting Command
Get Parameter
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.
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.
Save Current Setting Command Reply
The monitor replies to the
controller for confirmation.
Header
Message
Check Code
Delimiter
Header
Message
Check Code
Delimiter
Header
Message
Check Code
Delimiter
Header
Message
Check Code
Delimiter
Header
Message
Check Code
Delimiter
Header
Message
Check Code
Delimiter
Header
Message
Check Code
Delimiter
Monitor Controller
Header
Message
Check Code
Delimiter
Header
Message
Check Code
Delimiter