Digital Alert Systems DASDEC-II MANUAL - Manual (Page 12)

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Digital Alert Systems: DASDEC User Manual
2
Setup: Hardware
2.1 Audio Wiring
Audio wiring on the DASDEC II has some flexibility due to the option of adding a second sound card and because of built-
in software control. Here are a few rules:
 EAS decoder input uses the analog audio line inputs or internal radio receivers.
 Each available analog line input can be used for decoding audio provided from an external receiver or another
EAS encoder. The web interface must be used to set an audio device input source from internal radios to line
input. Line input is NOT available on the AES digital card.
 An audio line input supports two (2) EAS decoders. The left side of the input is decoded separately from the right
side. So two line inputs provide four (4) EAS decoders.
 EAS alerts are selectively played out of the analog and/or digital line output ports. Software is used to select which
audio ports are used during alert origination and forwarding.
The Main analog audio output is instead routed out through the balanced audio output port. This output is
available on the screw terminal connector. The balanced audio hardware also features balanced stereo analog
audio input pass through for routing analog program audio through the DASDEC II. The inputs are also available
on the screw terminal connector. EAS alert play-out overrides the main audio output during the alert notification
(this is software configurable; the DASDEC II can be made to always override the input pass through source).
Audio pass through continues to operate when the DASDEC II is unpowered.
 The main or aux microphone inputs can be used to record EAS audio messages. The ALSA sound software
option is required for these recordings to be clearly audible. DASDEC IIs come equipped with both OSS and
ALSA sound system options. The option can be selected from the Web interface by the Admin user.
 AES Digital audio output is available as a hardware option. The AES option occupies one of the two PCI slots. It
provides both analog and digital audio output via two breakout cables. It also provides a separate output
monitoring analog mini-jack. The AES hardware option requires the ALSA sound system.
For decoding, each side of the stereo input of any audio input can be selectively used as a single decoder source. In other
words, one stereo input supports two EAS decoders. A dual RCA to 3.5 mm jack input adapter can be used to connect
two separate mono input signals to a DASDEC II line input jack.
For alert encoding/origination, an audio cable is run from the main balanced audio output or from software selected 3.5
mm line output jack into your systems alert audio wiring. Only analog audio output is supported.
2.2 AES Digital Audio Wiring
The DASDEC II includes the capability for an AES digital audio output, and a Failsafe AES audio loop through. Refer to
the diagrams below for cabling of the AES audio inputs and outputs.
NOTE: The SPDIF digital audio output port is not used.
NOTE: Audio input and digital audio pass-through is NOT available with this hardware option.
See Section 1.5 later on in the manual.
NOTE: The standard balanced audio hardware disables the main audio line out mini-jack.