QSC Audio Network Audio Systems Architect’s and Engineer’s Specification, Network Interface

Contact Closure Inputs and Outputs

Inputs	1 discrete input
Configuration	Single-ended input
Resistance for closure detect	< 1kΩ	max
Resistance for open detect	> 5kΩ	min
Input voltage limit	7.000 VDC maximum
	(“-” input terminal connected to chassis)
Output	1 discrete output
Configuration	Electromechanical relay, dry contacts,
	floating, C, NC, NO
Maximum steady-state current	0.5A
Maximum switched current	0.25A
Ground isolation	70V maximum
Connector	“Phoenix-style” (a.k.a. “Euro-style”)
	detachable terminal block connectors
Network Interface
Physical Network	Ethernet
Raw data rate	10 megabits per second
Frame format	D.I.X. (Ethernet)
Connector	RJ-45 female
Ethernet type	10BASE-T: (via RJ-45)
Cable type	10BASE-T: CAT-3 (or better) twisted pair
Max cable length	10BASE-T: 100 m to hub
Grounding	Floating
Transport Network	TCP/IP
Internetwork protocol	IP
Transport protocol	UDP
Application Protocol	QSC24
Version	1
Revision	7
General
Physical
Height	1.72" (1RU)
Width	19" (standard rack mount)
Depth	14.84" (37.7 cm), including rear supports
Weight	11 lbs. (5 kg)
Mounting	Rear support recommended for portable
	or mobile use
Operating Temp.	0 to 50° C
AC Power
Voltage	100-240 VAC (Universal Supply)
Current	1A RMS @ 120V, 1.1A RMS @ 100V,
	0.5A RMS @ 230V
Frequency	47–440 Hz

Specifications subject to change.

Architect’s and Engineer’s Specification

The CM16a Amplifier Network Monitor shall provide input, output, status monitoring, and control for DataPort equipped QSC power amplifiers in an Ethernet-TCP/IP based network audio system. Sixteen independent channels shall be provided, grouped in pairs to support up to sixteen power amplifier channels.

Amplifier Input Control and Monitoring. For each of the sixteen power amplifier input signals, the CM16a shall provide level, mute and polarity control, pre- and post-fader signal level metering and audio monitoring, and selectable +4 dBu/-10 dBV (3V/1V) input sensitivity.

The CM16a shall provide a page input, separate from the normal program inputs, whose signal may preempt the program signal of any or all of the sixteen program channels. This input shall have selectable +4 dBu/-10 dBV (3V/1V) sensitivity.

The CM16a shall provide for the storage and recall of up to sixteen different presets, numbered 0 through 15. Each preset shall be a “snapshot” of all of the CM16a functions and settings. Preset #0 shall be the default boot-up preset.

Amplifier Output Monitoring. For each of the sixteen power amplifier outputs, the CM16a shall provide clip detect monitoring, short/open circuit detect, voltage and current metering, amplifier headroom, load impedance, real output power to load, and audio monitoring of the voltage signal.

Amplifier Management. For each of the DataPort connected power amplifiers, the CM16a shall provide AC standby/operate mode control, AC power state indication, temperature metering, amp gain settings (front panel knob position with respect to full output), over-temperature detection, stereo/parallel/bridge-mono indication, amplifier model detection, and protect status detection (subject to the capabilities of each amplifier).

Audio Monitoring Chain. For each of the sixteen program channels, the CM16a shall provide three monitor points as follows: (1) pre-fader level control, (2) post-fader level control, or (3) power amplifier output. A channel’s monitor output may be selected from one of these three signals, or it may be switched off. The signal at the CM16a’s monitor output connector shall be the sum of the signal at its monitor input connector and as many as four of the sixteen channel monitor signals at one time per CM16a. A monitor level control shall be provided for each monitor tap point to adjust the individual levels of the channel monitor signals prior to their being mixed with the monitor input signal.

Contact Closure I/O. The CM16a shall provide one trigger contact-closure sense input which shall also be TTL signal compatible, and one dry- contact floating SPDT relay output. These shall be under software control, with functions definable by the QSControl custom software application. The contact closure sense input shall be capable of toggling between presets 14 and 15, regardless of the computer’s connection status.

Data Network. All CM16a functions shall be controlled and monitored via an Ethernet digital control network using the TCP/IP transport protocol and the QSC-24 control and monitoring application protocol. Rear-panel connections shall be provided for 10BASE-T Ethernet utilizing a standard RJ-45 Unshielded Twisted Pair Category-5 connection. Other than the AC power and bypass switches, the CM16a shall have no manual controls. A 9-pin, “D” subminiature connector shall be provided to allow interfacing to an RS-232 connection. This connector shall be used for CM16a setup, testing, diagnostics, and limited control functions.

Amplifier Interface. The CM16a’s interface to each power amplifier DataPort shall be via a HD-15 connector. The amplifier interface shall use a standard personal computer Video Graphics Adapter (VGA) CRT monitor cable 1. This interface shall transmit two amplifier input audio signals as well as all control and monitoring signals. Special signal conditioning and grounding techniques shall be used in this interface to ensure negligible levels of noise and crosstalk.

General. All audio inputs and outputs shall be balanced with a nominal input level of +4 dBu and maximum level of +21 dBu. Input connectors shall be of the “Euro-style” depluggable barrier strip type.

1QSC DataPort cable required for connection with QSC DSP devices.

2For lengths greater than 2 meters, a QSC DataPort cable is recommended.