Audio Terminals; Audio Input; Audio Output - March Networks 8704 S Hybrid NVR Installation Manual

Audio Terminals

Audio in and out terminals are available on the back of the unit. Terminals provide line level audio input/output.
Audio terminals
Pinout
Relay RS232
NC C NO Rx
A1 G A2 Tx
Alarms

Audio Input

Connect an audio cable to the Audio In terminal block. Use the audio cable to connect an audio
input device, such as a microphone, to the unit. Audio In pin 1 and 2 are the signals for audio input
channel 1 and 2 respectively. Connect the return to the "G" between the two audio inputs.
If you are connecting a microphone to the unit, you must use a pre-amplifier to amplify the signal to
line level. Place the pre-amplifier close to the microphone for best results.
Input specification: unbalanced, 10 kΩ, 1Vp-p (line level)

Audio Output

Connect an audio cable to the Audio Out terminal block. Use the audio cable to connect an
amplified audio output device, such as an intercom or speaker, to the unit. Ensure that the audio
output device (whether intercom or speaker) includes a built-in amplifier.
Audio Out pin 1 is the signal for audio output channel 1. Connect the return to the "G" beside the
audio output.
Output specification: unbalanced, 600 Ω, 1Vp-p (line level)
8704 S Hybrid NVR (Gen 2) Installation Guide
Audio Out
G G 1
1 G 2
Audio In
Feature Overview
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