This mutes the program audio only and not the microphone.
Where ## is the current level of the selected input.
Request number of currently selected input
Where # is the input number.
Where ## is the current level
Where ## is the level from +12 to -48
Input 1 shown. Other inputs are identical just substitute 1 with 2, 3, or 4
To select Input 2 and increment its volume
Send in ASCII the command
Followed by the command
This will increase the volume of Input to by 1 step
Send the command repeatedly to increase the volume by further steps.