User Guide

NXC-VOL4 Volume Control Card
43
NXF CardFrame, NetLinx Control Cards, and NetModules
NXC-VOL4 Connections/Wiring
The NXC-VOL4 card contains four audio volume control channels. Each line-level channel is
isolated from system ground and can be configured for balanced or unbalanced line operation. It
supports programmable audio levels, audio mute, variable ramp speeds, and preset levels. Each
audio channel's input to output gain ratio is adjustable via the on-board jumpers shown in FIG. 8 on
page 41.
 Unity (jumper not installed)
 Gain (-10 dB Input level/+4 dB Output level setting on pins 1 and 2)
 Attenuate (+4 dB Input level/-10 dB Output level setting on pins 3 and 4)
NXC-VOL4 Channel Assignments
The NXC- VOL4 channel assignments are listed in the following table. This card has 2 ports with 2
audio "channels" in each port. The two audio "channels", which can be used as right and left,
should not be confused with the channel assignments, which are sent to and from the card.
Ramping a volume channel while the mute channel is on will not automatically turn off the mute
channel but the ramping will still occur; the volume change will be noticed when the mute channel
is turned off. For setting ramp rates and presets, refer to the Programming Information section on
page 45.
NXC-VOL4 Channel Assignments (per port)
Port 1
Channel:
Port 2
Channel:
Description
1 1 While channel is on, ramps the volume on audio channels 1 and 2 up (increase).
2 2 While channel is on, ramps the volume on audio channels 1 and 2 down (decrease).
3 3 While channel is on, the volume on audio channels 1 and 2 are muted (lowest
volume); when channel is off, the volume levels are restored to their previous levels.
4 4 While channel is on, ramps the volume on audio channel 1 up (increase).
5 5 While channel is on, ramps the volume on audio channel 1 down (decrease).
6 6 While channel is on, the volume on audio channel 1 is muted (lowest volume); when
channel is off, the volume level is restored.
7 7 While channel is on, ramps the volume for audio channel 2 up (increase).
8 8 While channel is on, ramps the volume for audio channel 2 down (decrease).
9 9 While channel is on, volume for audio channel 2 is muted (lowest volume); when
channel is off, the volume level is restored.