Drake OBM100 Data Modulator - Manual (Page 6)

6 General Description / Installation and Mounting
OBM100 QPSK DATA MODULATOR
OBM 100 1.4
DHCP............
ENT ER
RF OUT PUT ASI INPUTS E THE RNE T RS232
AC POWE R
120 VAC 60 Hz
10 WATTS
OBM100 MAC ADDRESS
OUT OF BAND M O DU LAT O R
1 2 3 4
*0000000000000000*
OBM100 DESCRIPTION
The OBM100 is an out of band data modulator for use with
the SCT2X4 headend satellite to cable transcoder. The
purpose of the OBM100 is to provide a one way data
channel from the headend to a universe of set top boxes that
are being served by the headend. Usually program guide
and conditional access control information will be sent
through this channel.
The OBM100 provides two functions in the data manage-
ment process. First of all it accepts an ASI transport stream
from the SCT2X4 data output connector. This is data that is
sent over the satellite path to the headend. The OBM100
takes this low data rate stream and without making any
changes to the data, outputs the data through an Ethernet
connection to the headend control PC.
After the headend PC constructs a complete data stream for
the set tops, derived from the satellite delivered data and
from locally generated data, the resulting stream is output
from the headend control PC back to the OBM100 on the
same Ethernet cable that is passing the satellite delivered
data in the other direction. The OMB100 accepts this incom-
ing data and performs its second function – transmitting this
data stream to the set top boxes.
The OBM100 generates a QPSK modulated signal, modu-
lated by the data stream from the headend controller, at a
data rate of approximately 3 Mbps. This signal is upconverted
to any operator selected frequency between 70 and 130 MHz
for transmission throughout the cable plant.
INSTALLATION AND MOUNTING NOTES
This equipment is designed to be installed in a standard 19”
rack. When the unit is mounted above or below other rack
mounted equipment, a 1U space (1.75”) should be left
between the unit and the other equipment to allow ambient
air flow between the units.
Connect a cable from the OBM100 Ethernet connector to the
Ethernet connector on the PC based headend controller.
Connect each of the four ASI INPUT connectors of the
OBM100 to the ASI DATA connectors of the Drake SCT2x4
Transcoders in the system.
TYPICAL Drake BBT HEADEND INSTALLATION
R S232 in
Drake S CT 2X4 R F Ou t 4 QA M C hann el s
S at ellit e to Q AM
Tr a nsc ode r Drak e
R S232 in
Drake S CT 2X4 R F Ou t 4 QA M C hann el s PC 12 01
S at ellit e to Q AM
Tr a nsc ode r 12 w ay
A vai l M e d ia/ BB T R S2 32 in
T ra ns p ort Drake S CT 2X4 R F Ou t 4 QA M C hann el s C om b ine r
S at ellit e to Q AM
Tr a nsc ode r T o Sub s cri bers
R S232 in
Drake S CT 2X4 R F Ou t 4 QA M C hann el s
S at ellit e to Q AM
Tr a nsc ode r A SI Da ta o u t
H ead- end Co n tro ll er
PC B as ed
Connect the OBM100 RF OUTPUT connector to the output
Eth e rnet
Eth e rnet Dat a
C o n tr ol D at a
combiner which sends downstream RF.
Connect the AC line cord to an appropriate source of 120
volt, 60 Hz AC power. The OBM100 is always on once the
AC power cord is connected to its power source.
D rak e OB M1 00
D rak e D QT 1 000 2 56 QAM o ut
2 8VS B to 1 Q AM R S2 32 in
D rak e D QT 1 000 2 56 QAM o ut
2 8VS B to 1 Q AM R S2 32 in
12 N TS C in p ut s A n alo g to D ig i ta l E H 24 u p t o 1 2 M P EG2 /4 p rog ram s o ut at 6 4 or 25 6 QAM
6 d ual M PEG En co ders R S232 in
IP con n e ct io n
SC T e ci IP Con t rolle r R S2 32 o ut