FSR IT-VCM - Manual (Page 7)

7
IT- VCM Operation
The IT-VCM audio input and output may be wired for balanced or unbalanced applications.
Bridging inputs allow either high or low impedance sources. The output is line-level, low-
impedance balanced.
Depending on the “POT CONTROL” dipswitch setting, the IT- VCM can be set for two
operating modes. When set to DISABLE, the audio level is controlled by normally open
momentary pushbuttons (not provided) connected to the SWITCH INPUT terminals for ramp up
and ramp down the audio level. If either button is held in, the audio level will ramp
automatically. If a button is pulsed (< ½ second), the audio level will increment or decrement
one step. In this mode the Volume serial commands can also be used to control the volume level.
When the “POT CONTROL” dipswitch is set to ENABLE, the potentiometer terminals are
activated and the audio level is controlled by a remote 10 kΩ linear taper pot or by an externally
applied 0 to 12VDC. In this mode, the volume up and volume down button terminals as well as
the Volume serial commands are disabled
Terminals provide a 0 to 10VDC output ramp. The ramp output can be used to drive an LED bar
graph display to indicate the current audio level.
A momentary closure between the MUTE and GROUND terminals will mute the audio source.
A second closure will un-mute (toggle action). An on board LED and an LED output terminal
indicate when the IT-VCM audio level is muted.
Settings retention: All current settings are saved in non-volatile flash memory upon power loss.
Settings include: Volume, Bass, Treble, Balance, Mute and settings.
There are additional control features such as bass, balance and treble adjustments that are
available through the RS-232 control input and are discussed in the RS-232 protocol section.