1
Introduction 1
RB-SD1IP Silence Detection Unit
Introduction
Fig 1-1: RB-SD1IP Front Panel
The RB-SD1IP Silence detection unit is an upgraded version of the existing
Sonifex RB-SD1. The unit is a 1U rack mount device used to monitor an
unattended stereo studio feed and in the event of the signal going “quiet”
after a given period the unit will switch through an alternative stereo audio
signal. This signal could be a recorded message (e.g. “Normal service will
be resumed”, etc), a feed from a CD or minidisc player, or an alternative
recorded program. Controls are provided to start external equipment and to
provide remote status indication.
The RB-SD1IP has several new features in addition to the functionality of
the standard RB-SD1.
Ethernet connectivity provides the ability to set up and control the unit via
a browser based Graphical User Interface (GUI). The network capabilities
allow the user to more finely control silence Levels (-60dBu to 0dBu in 3dBu
steps) and Time delays (1 second to 24 hours), you can also remotely lock/
unlock the front panel controls on the unit and choose to use either the
hardware configured settings or web based settings. In addition to the front
panel LEDs the GUI home page also offers a real time view of signal levels
and alarm statuses.
Also using the GUI, left and right channels can be treated independently,
remote relay triggers can be configured as one of many events including
the new GPI pins. You can also choose to lock/unlock the use of the remote
pins to control the unit. Firmware updates can also be performed using the
web GUI.
SNMP V1 is implemented so that the unit can be monitored by existing
Network Management Systems (NMS). The addition of 6 extra GPI pins to
the rear panel, allows customisable functionality, including the use of the
RB-SD1IP network interface to generate SNMP Traps on behalf of other,
non-networked, hardware.
The RB-SD1IP has been fitted with a USB interface on the front panel and
can act as a host in two ways. Firstly the USB port can be used to upgrade
the firmware on the unit from a USB flash drive. Such a drive can also hold
a pre-recorded message which the unit can play out in the event that both
main and auxiliary signals both fall silent.
As on the standard RB-SD1, the RB-SD1IP has 2 balanced stereo audio
inputs with a maximum input level of +28dBu. Each input is user-defined as
either the main source or auxiliary source and all channels are monitored
for failure. In the event of the main source dropping below a pre-set level
for a pre-determined amount of time, the unit will automatically attempt
to switch through to a valid auxiliary signal. The silence detect level is
adjustable between -60dBu and -15dBu in 3dB steps via a 16 position rotary
switch on the rear panel. The silence interval can be adjusted between 2
seconds to 30 seconds in 2 second steps, or, alternatively, set to 2 minutes
5 seconds also via a 16 position rotary switch on the rear panel. More fine
control of the detection levels and times can be set using the web browser
based GUI. The audio inputs and outputs use stereo professional balanced
XLR-3 connectors.
