AXYS
®
Octadrive DSP-DN User Manual rev 2.0
201703/ODSPDN_2.0
7
The unit has two analogue inputs, making it suitable for
connection to primary and secondary audio sources in life-
safety applications. The inputs are transformer-balanced
and offer low noise and very high CMRR (Common-Mode
Rejection Ratio).
The audio transformers fitted to the analogue inputs are
of professional grade and provide full galvanic isolation
from source and destination equipment, eliminating the
potential for ground loops to occur between items of
equipment which may be running on different AC supplies.
The analogue input and A-D converter stages accept a peak
signal level of +21 dBV without clipping. (At high input
levels, the digital gain within the DSP block will normally
need to be reduced to avoid continuous activation of the
limiter section.)
Both inputs can be routed to all eight analogue outputs
via the DSP core.
Both analogue inputs feed a pilot tone detector so that
continuous monitoring of the input connections may be
made. The detector will, when enabled, switch from Input
1 to Input 2 if pilot tone is lost. The Octadrive DSP-DN
incorporates surveillance functions which activate an
externally-accessible failure relay in the event of a PSU or
other malfunction, or a loss of pilot tone.
A further sixteen digital inputs are also available. These
are routed to the DSP core along with the analogue inputs,
and are also continuously monitored for pilot-tone, with
the same auto-switching arrangement as the analogue
inputs. All active inputs (as enabled via WinControl) are
routed to all output channels.
Pilot tone generation is available on both the analogue
and digital audio outputs. The frequency and level settings
are independently software configurable for both of these
separate output types.
The microphone input can be used for either Ambient Noise
Sensing (ANS) or Paging applications. The monitoring
scheme is capable of detecting open circuit or short circuit
failures for either electret or dynamic microphone types.
For paging purposes the microphone signal processing
includes a low-cut filter, gain control and limiter. A
monitored Push To Talk (PTT) switch input is also available.
The Dante
™
interface is bi-directional, the analogue inputs,
some of the processed inputs as well as the analogue
outputs can be transmitted to the Dante
™
network. The
input from an optional ANS or Paging microphone is
available as an ‘unprocessed’ and a ‘processed’ output
channel on the Dante
™
interface.
The Dante
™
card also allows the Octadrive DSP-DN to be
controlled by WinControl via the AxysBridge protocol by
using the Dante
™
Ethernet interfaces. These interfaces can
either connect to primary and secondary 1 Gb/s Dante
™
networks, or provide daisy-chaining in non-redundant
operation mode.
The headphone amplifier can be used for local monitoring
of all analogue inputs and outputs.
The mains power supply is conservatively-rated and
operates on any AC supply voltage from 100 V to 240 V.
The back-up supply operates on a DC supply voltage from
12 V to 48 V.