LG M3704C Owner's Manual page 61

RS-232C
Transmission / Receiving Protocol
02. Aspect Ratio(Command : k c) (Main picture format)
► To adjust the screen format.
You can also adjust the screen format using the ARC
(Aspect Ratio Control) button on remote control or in the
Screen menu.
Transmission
[k][c][ ][Set ID][ ][Data][Cr]
Data 1 : Normal Screen (4 : 3)
2 : Wide Scran (16 : 9)
4 : Zoom (AV,Component,HDMI-DTV)
6 : Original (AV)
7 : 14 : 9 (AV,Component,HDMI-DTV)
9 : Just Scan (Component (HD DTV), HDMI-DTV (HD DTV))
* 1:1 (RGB, HDMI-PC)
10 to 1F : Cinema Zoom 1 to 16 (AV,Component,HDMI-DTV)
B : Full Wide (AV)
Acknowledgement
[c][ ][Set ID][ ][OK][Data][x]
03. Screen Mute(Command : k d)
► To select screen mute on / off.
Transmission
[k][d][ ][Set ID][ ][Data][Cr]
Data 0 : Screen mute off (Picture on)
1 : Screen mute on (Picture off)
Acknowledgement
[d][ ][Set ID][ ][OK][Data][x]
Controlling the Multiple Product
A6