Wall-plate transmitters allow users to chose between VGA and HDMI distribution. There are three ways to chose how formats are toggled between.
1) Use the physical toggle button to switch between VGA and HDMI (factory default setting):
astparam s v_input_select auto;astparam save;reboot
2) Detect a change in video signal connection and switch based on that change (choose most recently plugged-in video signal):
astparam s v_input_select detect_sync;astparam save;reboot
3) Dynamically toggle between VGA and HDMI over the command line: