Roland RSS Digital Snake S-4000, Owner'S Manual

Page: 37 / 108

S-4000 Digital Snake Owner’s Manual 37
5—S-4000 System Overview
The transmission protocol for REAC is based on 100BASE-TX (Fast Ethernet). To transfer 40
channels of digital audio, REAC uses the full bandwidth of this protocol. However, some 100BASE-
TX switching hubs cannot handle this amount of data traffic. Gigabit Ethernet switching hubs
can handle a larger amount of data traffic, so we recommend them for use with REAC devices
(just be sure that the Gigabit switching hub you use supports 100BASE-TX devices).
Consult the switching hub’s documentation for information on its proper use.
Built-in Redundant Connections
In case of an Ethernet cable failure, each REAC device provides two REAC ports—MAIN and BACKUP.
The MAIN port is used for the primary REAC connection, while the BACKUP port provides a redundant
backup. Should the primary connection fail, the backup connection will automatically take over. (Note:
Separate Ethernet cables are used for the MAIN and BACKUP connections.)
A/D-D/A Conversion and Signal Optimization
Before an analog audio signal can be transmitted through REAC, it must first be converted to digital
data. Once in digital form, the audio is sent down the Ethernet cable to the receiving REAC device.
When it arrives there, the signal is converted back to analog for connection to an audio device such
as an analog mixing console. This process of turning analog audio into digital data and back again is
called
analog-to-digital (A/D) and digital-to-analog (D/A) conversion.
The S-4000S and S-4000H units employ extremely high-quality 24-bit/96 kHz A/D and D/A converters
on all audio inputs and outputs for the very best possible sound quality.
Additionally, the S-4000S provides variable gain preamps on each of its 32 audio inputs. This allows
for signal optimization at the source, resulting in the highest A/D conversion quality.
RS-232C Serial Interface
The S-4000S and S-4000H feature REMOTE jacks that support the RS-232C serial interface protocol.
RS-232C is a standard communications interface found in computers.
The S-4000 System can be controlled from a remote device utilizing RS-232C, such as the included
S-4000R Remote Controller or a personal computer running the S-4000 Remote Control Software.
If RS-232C devices are connected to the REMOTE jacks on both the S-4000S and S-4000H, the
system can be controlled from either device (though only one remote device can control the
system at any given time).