AMX NXC-VOL4 User Manual

Installation Guide
NXC-VOL4 Volume Card, 4 Channels

NetLinx Control Cards and NetModules

NetLinx Control Cards can be installed in either the NXF CardFrame, NI-4000, or NetModules. This document provides basic specifications and wiring information for the NetLinx Control cards. For detailed information on the cards, refer to the NetLinx CardFrame, Control Cards, and NetModules Instruction Manual found on-line at www.amx.com.
The NXC-VOL4 Volume Control Card provides four discrete volume control channels with LED feedback. The volume control channels can be programmed for mono or stereo operation, and balanced or unbalanced audio connections.
It supports programmable audio levels, audio mute, variable ramp speeds and preset levels. Use the on-board jumpers to set the gain/attenuation (Unity, Pro level (+4dBu) to Consumer level (-10dBu) conversion, or Consumer level to Pro
level on each channel).
I/O Jumpers (CH1-CH4)
FIG. 1 NXC-VOL4 Volume Control card

Specifications:

NXC-VOL4 Specifications
Power Requirements 197 mA @ 12 VDC
Volume 1-4 Four volume channels
Status 1-4 (3 LEDs per channel)
Gain jumpers 1-4 • Unity
Connections/wiring Two 10-pin 3.5 mm captive-screw terminals
Audio Specifications • Frequency response of 15 Hz - 25 KHz
Models • NXC-VOL4 Volume Card
Yellow LED shows level-up/down activity. Red LED shows mute mode:
• LED 1: Channel 1 RAISE (yellow)
• LED 2: Channel 1 LOWER (yellow)
• LED 3: Channel 1 MUTE (red)
• LED 4: Channel 2 RAISE (yellow)
• LED 5: Channel 2 LOWER (yellow)
• LED 6: Channel 2 MUTE (red)
• LED 7: Channel 3 RAISE (yellow)
• LED 8: Channel 3 LOWER (yellow)
• LED 9: Channel 3 MUTE (red)
• LED 10: Channel 4 RAISE (yellow)
• LED 11: Channel 4 LOWER (yellow)
• LED 12: Channel 4 MUTE (red)
Maximum Input Level: +10dBm
• Pro level to Consumer level conversion (attenuation of +4dBu IN to -10dBu OUT) Maximum Input Level: +10dBm
• Consumer level to Pro level conversion (gain of -10dBu IN to +4dBu OUT) Maximum Input Level: +6dBm
• THD less than.005% at nominal output level
• S/N ratio greater than 100 dB (IHF A)
• Crosstalk less than 80 dB
• Logarithmic attenuation range of 95 dB
• NXM-VOL4 Volume NetModule

Pinouts, Signals, and Functions:

NXC-VOL4 Pinouts, Signals, and Functions
Pin Signal Balanced Function Unbalanced Function
Channel 1
1 GND Audio GND Audio GND
2 Input 1+ Audio IN Audio IN
3 Input 1- Audio IN Audio GND
4 Output 1+ Audio OUT Audio OUT
5 Output 1- Audio OUT no connection
Channel 2
6 GND Audio GND Audio GND
7 Input 2+ Audio IN Audio IN
8 Input 2- Audio IN Audio GND
9 Output 2+ Audio OUT Audio OUT
10 Output 2- Audio OUT no connection
Channel 3
11 GND Audio GND Audio GND
12 Input 3+ Audio IN Audio IN
13 Input 3- Audio IN Audio GND
14 Output 3+ Audio OUT Audio OUT
15 Output 3- Audio OUT no connection
Channel 4
16 GND Audio GND Audio GND
17 Input 4+ Audio IN Audio IN
18 Input 4- Audio IN Audio GND
19 Output 4+ Audio OUT Audio OUT
20 Output 4- Audio OUT no connection
(jumper)
(jumper)
(jumper)
(jumper)

NXC-VOL4 Connections/Wiring:

The NXC-VOL4 card contains four audio volume control channels. Each line­level 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 below.
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 2 and 3)
NXC-VOL4 Volume Control card
FIG. 2

NXC-VOL4 Channel Assignments:

The NXC- VOL4 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 channels, which are sent to and from the card.
NXC-VOL4 Channel Assignments (per port)
Port 1 Channel:
1 1 While channel is on, ramps the volume on audio chan-
2 2 While channel is on, ramps the volume on audio chan-
3 3 While channel is on, the volume on audio channels 1 and
4 4 While channel is on, ramps the volume on audio channel
5 5 While channel is on, ramps the volume on audio channel
6 6 While channel is on, the volume on audio channel 1 is
7 7 While channel is on, ramps the volume for audio channel
8 8 While channel is on, ramps the volume for audio channel
9 9 While channel is on, volume for audio channel 2 is muted
Port 2 Channel: Description
nels 1, 2 up (increase).
nels 1 and 2 down (decrease).
2 are muted (lowest volume), and when channel is turned off the volume levels are restored to their previous levels.
1 up (increase).
1 down (decrease).
muted (lowest volume), and when channel is turned off the vol­ume level is restored.
2 up (increase).
2 down (decrease).
(lowest volume), and when channel is turned off the vol­ume level is restored.
Ramping a volume channel while the mute channel is on will not automatically turn off the mute channel but the ramping will still occur, and the volume change will be noticed when the mute channel is turned off.
For setting ramp rates and presets, refer to the Send_Commands. For reading current volume levels and displaying bargraphs see CREATE_LEVEL and SEND_LEVEL programming instructions. Volume (audio) channels 1 and 2 use levels 1 and 2 respectively.
Note: When controlling levels, such as with an active bargraph, there is no LED indication of volume changes.

NXC-VOL4 Levels:

Volume (audio) channels 1 and 2 use levels 1 and 2 respectively. For reading current volume levels and displaying bargraphs see CREATE_LEVEL and SEND_LEVEL. The two levels associated with each port of the NXC-VOL4 Control Card are listed in the table below:
NXC-VOL4 Levels
Port 1 Port 2
Level Description Level Description
1 Output #1 1 Output #3
2 Output #2 2 Output #4

CREATE_LEVEL

This keyword creates an association between a specified level of a device and a variable that will contain the value of the level. This can only appear in the DEFINE_START section of the program.
CREATE_LEVEL DEV, Level, Value
Parameters:
• DEV: The device from which to read the level.
• Level: The level of the device to read.
• Value: Variable in which to store the level value.
• DevLev: A DEVLEV structure.
• Value: Variable in which to store the level value CREATE_LEVEL DevLev, Val ue.
During execution of the program, NetLinx continuously updates the variable to match the level that it represents.

SEND_LEVEL

This keyword sends a value to a specific level on a NetLinx device/port. The syntax follows any one of the four following examples:
SEND_LEVEL DEV, Level, Value SEND_LEVEL DEV[ ], Level, Value SEND_LEVEL DEVLEV, Value SEND_LEVEL DEVLEV[ ], Value
Parameters:
• DEV: Device containing the specified level
• Level: Number of the level to receive the new value
• Value: New level value
• DEV[ ]: Device array (each device contains the specified level)
• DEVLEV: Device-level to receive the new value
• DL[ ]: Device-level array (each will receive the new value)

Programming Information:

These NetLinx Send_Commands control the NXC-VOL4.
NXC-VOL4 Send_Commands
PL
Ramps specified (audio) channel(s) from current level to a specified preset level or percentage at the current rate, or optionally in a specified amount of time.
PR
Sets the ramp rate of the specified channel(s) where Time is the time to ramp the full range both down to up and up to down, or optionally just down to up or just up to down.
Syntax:
SEND_COMMAND <DEV> 'P<Output Channel>L<Level>[T<Time>]'
Variables:
Output Channel: Target audio channel number (0-2). Output channel 0 means both channels 1 and 2.
Level: Target level (0-255 or 0-100%). Level 0 is lowest volume (mute) and 255 (or 100%) is maximum volume.
Time: Specifies the amount of time (in .10-second increments) it takes to ramp the specified audio channel to the specified level.
Example:
SEND_COMMAND MYDEVICE1, 'P0L50%' SEND_COMMAND MYDEVICE2, 'P0L50%'
Respectively, MYDEVICE1 is port 1 or channels 1 and 2 and MYDEVICE2 is port 2 or channels 3 and 4.
This ramps both audio channels to 50% volume at the current ramp rate.
If Time is set to 50, it takes 5 seconds to ramp through the full range of 0 to 255 (0-100%). It would take 2.5 seconds to ramp through half of the range and so on.
Syntax:
SEND_COMMAND <DEV> 'P<Output Channel>R<Time>[U|D]'
Variables:
Output Channel: Target channel number (0-2). Output channel 0 means both channels 1 and 2.
Time: Specifies the amount of time (in .10-second increments) that it would take to ramp the full range of 0-100% (down to up and up to down or optionally just down to up or just up to down).
U|D: Ramp the specified channel(s) from down to up (U) or from up to down (D).
Example:
SEND_COMMAND MYDEVICE 'P0R50'
Sets ramp rate of audio channels 1 and 2 to five sec­onds full range from down to up and up to down.
For full warranty information, refer to the AMX Instruction Manual(s) associated with your Product(s).
©2007 AMX. All rights reserved. AMX and the AMX logo are registered trademarks of AMX.
3000 RESEARCH DRIVE, RICHARDSON, TX 75082 • 800.222.0193 • fax 469.624.7153 • technical support 800.932.6993 • www.amx.com
AMX reserves the right to alter specifications without notice at any time.
12/07
93-2024 REV: D
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