OPTICAL SYSTEMS DESIGN
DOC ID: 10104512
OSD860 OPERATOR MANUAL
PAGE 2
1
TECHNICAL SUMMARY
1.1
PRODUCT DESCRIPTION
The OSD860 series is a high-quality digital video, data, audio and IP optical fiber transmission system.
The system consists of an OSD860 transmitter and OSD860 receiver which are designed to be used as
a pair. The OSD860 standard product provides forward transmission of two, four or eight channels of
PAL, NTSC or SECAM video and one way transmission of four data channels. The OSD860 can also
be configured with the following options;
•
Full duplex data operation.
•
Transmission of four audio and/or four additional high speed data channels.
•
Reverse path transmission configured to provide any combination of four audio channels
and/or four data channels.
•
Alternatively, the system may transmit eight audio only or eight data only signals either one
way or full duplex.
•
10/100 Base-T Ethernet connections via an RJ45 connector.
The basic OSD860 transmitter has up to eight analogue composite video inputs which are converted to
a digital signal with 9-bit resolution. The four digital data inputs can be RS232 on two channels, TTL
or RS422 on the other two channels, with RS485 available on one channel, and operate from DC to
150kbps. Another added option allows a further 4 or 8 high speed data channels operating up to
400kbps. User adjustable turnaround times are provided for the RS485 on the optional data channels
and a fixed 100us turnaround time for the standard channel.
The OSD860 transmitter can be optionally supplied with up to eight analogue audio channels where the
audio signals are converted using 24-bit resolution. The audio channels can be balanced or unbalanced
at 775mV nominal level and operate over a 15kHz bandwidth.
10/100 Base-T Ethernet connection is also a fitted option.
The resulting digital signals are multiplexed and transmitted as a digital bit-stream through the fiber as
a laser light source operating at 1310nm or at 1550nm including the eighteen CWDM wavelengths
between 1270 and 1610nm. Various transmitter power levels and receiver sensitivities are available
providing cost effective operation over up to 120km. Two fibers are normally employed, one for each
direction of transmission. Single fiber full duplex operation is possible by employing wavelength
division multiplexing (WDM).
The OSD860 transmitter also includes an optical receiver section that decodes the digital signal
transmitted by the OSD860 receiver, to provide data, optional audio and Ethernet output signals.
The OSD860 receiver incorporates a high performance optical receiver for the incoming digital bit-
stream. The received digital signal is then decoded into video, data and audio signals, which are
available at the unit’s outputs. The OSD860 receiver also includes a transmitter that outputs a digital
optical signal consisting of the return path channels for audio and/or data and IP. The unit provides
constant analogue composite video output level which is independent of link loss, and the audio and
data sections of the OSD860 receiver are also adjustment free over all link lengths.
The OSD860 is available in three physical configurations: 10T card, stand-alone modem case and 2RU
rack mounting chassis. The 2RU version allows two OSD860 units effectively doubling the video,
audio and data available in a single unit. The card versions are designed to fit the 3RU-high 19”
OSD370 or OSD350 chassis allowing multiple OSD card products to be conveniently powered from
and located in the one chassis. The module versions are intended for isolated use and require an
external power source of +10 to +18V
DC
. The 2RU rack mounting chassis is a fully independent mains
or -48V powered unit.
Summary of Contents for OSD860 SERIES
Page 2: ......
