Telecast
Introduction
1
Introduction
The Telecast Adder
TM
882 System consists of two Adder 882 Þber optic
multiplexer/demultiplexers that simultaneously send and receive up to eight audio signals, eight
digital datas, and four remote relay closures in each direction. These signals are transmitted on
optical Þbers. Audio inputs are set up by internal DIP switches that set ampliÞer gain to accept
either mic or
line levels. Audio outputs are always at line levels. Digital inputs and outputs are
RS-422 and RS-232 compatible signals. Four of the digital connectors also provide contact
closure input and output. The other four connectors alternatively provide SONY CCU compatible
interfaces. All connections are made via the rear panel. See Figure 1.
Figure 1. Rear Panel of the Adder 882
Within an Adder 882 unit, the audio signals are Þrst digitized and then multiplexed with the
digital data and control signals. The combined electrical signal is converted to an optical signal,
launched into the optical Þber and sent to a second Adder 882. This second unit receives the
optical signal, converts it into an electrical data stream, demultiplexes the signals and restores the
audio signals to analog levels.
An internal Ni-Cad battery provides backup in the event of line power loss.
The Adder 882 is available with several optical options and conÞgurations.
¥ Standard connection with bidirectional signals carried on two optical Þbers at either 850, 1300,
or 1550 nm.
¥ One Þber connection with optically combined bidirectional signals at 850/1300 nm or
1300/1550 nm as shown in Figure 2.
In a standard two Þber system,
identical
Adder 882 units are used at each location. The units both
transmit at 850 nm on ST connector
A
and receive the 850 nm signal on ST connector
B
. They are
connected by the two Þbers so that the optical output of each box is connected to the optical input
of the other. In both one and two Þber systems, the input of channel 1 on one unit becomes the
output of channel 1 on the other unit, and vice versa.
In a one Þber system, the two Adder 882 units are
not identical
and are conÞgured before
shipment. They must be used as a pair. The units are connected by a single Þber that is wavelength
division multiplexed (WDM). One unit transmits from the
A
ST connector at a wavelength of
1300 nm and also receives at 850 nm on the same connector. The other unit transmits from the
A
ST connector at 850 nm and similarly receives at 1300 nm on the same connector.
Figure 3 illustrates available optical conÞgurations of the ADDER 882.
2AMP, SLO BLO
AUDIO IN 1
AUDIO OUT 1
DC INPUT
12-24VDC
OPTICAL I/O
A(Tx)
B(Rx)
DATA I/O
AUDIO IN 2
AUDIO OUT 2
AUDIO IN 3
AUDIO OUT 3
AUDIO IN 4
AUDIO OUT 4
AUDIO IN 5
AUDIO OUT 5
AUDIO IN 6
AUDIO OUT 6
AUDIO IN 7
AUDIO OUT 7
AUDIO IN 8
AUDIO OUT 8
1
3
5
7
2
4
6
8
