Cisco Model D9479 Gigabit QAM Modulator Technical References
Sample Rack Configurations
This section provides two fully loaded and recommended rack
configurations for setting up your GQAM modulator. They include the
following configurations:
configurations for setting up your GQAM modulator. They include the
following configurations:
• Rack with a top-mounted exhaust fan
—Includes a 40 rack unit
(RU) configuration with up to 32 GQAM modulators. The remaining 8
RUs are configured with 4 vacant RUs at the top and 4 vacant RUs at
the bottom of the rack.
RUs are configured with 4 vacant RUs at the top and 4 vacant RUs at
the bottom of the rack.
The 4 RU space at the top of the rack is covered with closed panels
and uses an exhaust fan (top of rack) to draw the heated air upward
and out of the rack. This 4 RU space also allows the ventilation space
for the exhaust fan to operate efficiently.
and out of the rack. This 4 RU space also allows the ventilation space
for the exhaust fan to operate efficiently.
Note: Use an exhaust fan that allows air, at a minimum of 600 cubic feet
per minute (cfm), to flow through the rack (2000 cfm is the ideal rate).
The 4 RU space at the bottom of the rack is vented on the front and
back of the rack. The vents allow air to freely enter the rack and cool
the GQAM modulators.
the GQAM modulators.
• Rack with floor plenum forced air cooling
—Includes a 40 RU
configuration with up to 32 GQAM modulators. The remaining 8 RUs
are configured with 4 vacant RUs at the top and 4 vacant RUs at the
bottom of the rack.
are configured with 4 vacant RUs at the top and 4 vacant RUs at the
bottom of the rack.
The lower 4 RU spaces are covered with solid panels and the upper
4 RU spaces are vented along with the entire top of the rack. The floor
plenum forced airflow must allow air, at a minimum of 600 cfm, to flow
through the rack (2000 cfm is the ideal rate).
plenum forced airflow must allow air, at a minimum of 600 cfm, to flow
through the rack (2000 cfm is the ideal rate).
GQAM Modulator Installation
and Connections
and Connections
Complete steps 1 through 10 to install and connect the GQAM modulator
into the rack unit.
into the rack unit.
Important: Refer to the back page of this quick reference guide to view
the front and back panels of GQAM modulator models, as well as the
connection ports.
the front and back panels of GQAM modulator models, as well as the
connection ports.
WARNING: To avoid electrical shock, perform only the
instructions that are included in steps 1 through 10. Refer all
servicing to authorized service personnel.
servicing to authorized service personnel.
1
Installing the GQAM Modulator
into a Rack
into a Rack
CAUTION: Do not tangle or strain interconnecting cables.
Use caution when installing wiring and racks to avoid obstruction
of airflow into the side air vents of the GQAM or out of the vent
fans on the side of the GQAM.
of airflow into the side air vents of the GQAM or out of the vent
fans on the side of the GQAM.
Important: You must use the supplied notched rack mounts to provide
additional support and to allow correct air circulation through the unit.
Using standard L brackets will restrict airflow and cause the GQAM
modulator to overheat.
additional support and to allow correct air circulation through the unit.
Using standard L brackets will restrict airflow and cause the GQAM
modulator to overheat.
Complete these steps to install the GQAM modulator into the rack.
a. Unpack and inspect the GQAM modulator.
b. Record the MAC address from the label on the underside of the
GQAM chassis.
MAC
Address:
_____________________________________________
c. Install the supplied rack mounts.
Important: The supplied rack mounts (Cisco part numbers 734845
and 734846) must be used. When you use the supplied rack mounts,
you can install the GQAM above or below each other in the rack with
no space required.
and 734846) must be used. When you use the supplied rack mounts,
you can install the GQAM above or below each other in the rack with
no space required.
d. Place the GQAM modulator in the rack.
e. Insert a mounting screw through each of the four bezel mounting holes
on the front panel of the GQAM modulator and then into the rack.
f. Firmly tighten each mounting screw.
2
Connecting the Power Sources
Follow these steps to connect an earth ground and either a DC or an AC
power source to the GQAM modulator.
power source to the GQAM modulator.
Connecting an Earth Ground
CAUTION: The 48 VDC GQAM must be connected to an
earth ground.
a. Place a ground wire onto the ground lug (labeled GND) on the back
of the GQAM modulator.
b. Tighten the ground lug to secure the ground wire.
c. Connect the other end of the ground wire to the rack or to an earth
ground.
Connecting a DC Power Source Only
a. Verify that the DC power source is set to the OFF position.
b. Insert the wires from the DC power source into the terminal block
connector.
c. Use a small flat-blade screwdriver to tighten the screws at the top of
the terminal block connector to secure the wires.
d. Insert the terminal block connector into the terminal block on the back
panel of the 48 VDC GQAM modulator.
e. Keep the DC power source set to the OFF position until you are ready
to power on the GQAM modulator.
Connecting an AC Power Source Only
a. Verify that the power switch on the back of the GQAM modulator is
placed in the OFF position.
b. Connect the power cord to the AC power inlet on the back panel of
the 120/230 VAC GQAM modulator.
c. Connect the other end of the power cord to an AC electrical outlet.
d. Keep the power source set to the OFF position until you are ready to
power on the GQAM modulator.
3
Connecting DVB ASI Input Ports
Follow these steps to connect the RF input ports on the rear panel of the
GQAM modulator to the distribution plant (combiner).
GQAM modulator to the distribution plant (combiner).
a. Locate the 75-ohm coaxial cable attached to the DVB ASI source.
b. Attach the other end of this cable to one of four DVB ASI IN ports on
the rear panel of the GQAM modulator.
4
Connecting the 10/100BASE-T
Ethernet Port
Ethernet Port
Follow these steps to set up an Ethernet connection and enable the DNCS
to perform system management and diagnostics.
to perform system management and diagnostics.
a. Connect one end of a screened or shielded CAT-5 cable with an
RJ-45 connector to the rear panel of the GQAM modulator.
b. Connect the other end of this cable to the Ethernet hub.
5
Connecting to the Gigabit Ethernet
Port
Port
Follow these steps to connect a data sharing device (for example, the
DNCS or a video-on-demand [VOD] server) to the gigabit ethernet (GbE)
port on the GQAM modulator.
DNCS or a video-on-demand [VOD] server) to the gigabit ethernet (GbE)
port on the GQAM modulator.
a. Insert the gigabit interface converter (GBIC) into the GbE port on the
back of the GQAM modulator.
b. Depending on the type of GBIC you are using, connect the data
sharing device to the GQAM modulator using one of the following
methods:
methods:
•
Use two single-mode or multimode fiber cables with a type SC
connector (one for input and one to output data)
connector (one for input and one to output data)
•
Use 8-conductor CAT-5 Ethernet 10/100BASE-T wiring with
RJ-45 connectors
RJ-45 connectors
Note: The copper GBIC includes a ferrite clamp. Attach this clamp
as close as possible to the GBIC end of the Ethernet cable.
6
Provisioning the GQAM Modulator
on the DNCS
on the DNCS
To provision the GQAM modulator as a Digital Broadband Delivery System
(DBDS) element on the Digital Network Control System (DNCS), refer to
the Gigabit QAM Modulator Model D9479 Installation and Operation
Guide.
(DBDS) element on the Digital Network Control System (DNCS), refer to
the Gigabit QAM Modulator Model D9479 Installation and Operation
Guide.
7
Powering On the GQAM Modulator
Follow these steps to power on the GQAM modulator.
a. Place the power switch on the GQAM modulator in the ON position.
b. Verify that the GQAM modulator boots.
8
Connecting RF Out Ports
CAUTION: Turning on the GQAM modulator with the default
RF output level may cause RF interference with the services
of other units connected to the network. Therefore, set the
RF output level before you connect any RF OUT ports to the
network or distribution plant.
of other units connected to the network. Therefore, set the
RF output level before you connect any RF OUT ports to the
network or distribution plant.
Follow these steps to connect the RF out ports on the rear panel of the
GQAM modulator to the distribution plant (combiner).
GQAM modulator to the distribution plant (combiner).
a. Connect one end of a 75-ohm coaxial cable to each RF OUT port on
the GQAM modulator, as needed.
b. Connect the other end of each cable to the distribution plant
(combiner).
9
Verifying RF Output
To verify that you have established the correct RF output for the RF OUT
port, follow these steps.
port, follow these steps.
a. Connect an RF OUT port on the GQAM modulator to a spectrum
analyzer.
b. Verify the output level for the frequency and the channel using a
spectrum analyzer.
c. Repeat steps a and b for the remaining RF OUT port connections.
10
Verifying Audio and Video
on a DHCT
on a DHCT
After sessions are defined on the DNCS, verify that audio and video are
performing properly on a local Digital Home Communications Terminal
(DHCT).
performing properly on a local Digital Home Communications Terminal
(DHCT).
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