Cisco Cisco Digital Service Access Node (DSAN) 8211 Installation Guide
Chapter 1 Startup Guide
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OL-29938-01
To Perform a Basic Power Check
After connecting the plant coax to the DSAN Input port, open the DSAN housing
and use a digital multimeter (DMM) to check for the correct AC and DC voltages at
the test lugs on the power supply module.
and use a digital multimeter (DMM) to check for the correct AC and DC voltages at
the test lugs on the power supply module.
Important: Before testing, confirm that an AC shunt is installed at the port with AC
power.
power.
To Check and Adjust Input Signal Levels
The cable plant signals enters the DSAN unit at its Input port (Port 1). An input pad
is used to set the downstream signal levels at the DSAN input, which in turn defines
the signal levels at the DSAN input tuners. The nominal DSAN input signal level in
the digital tier should be set to +4 dBmV. Analog carriers should be 6 dB higher in
level. A plug-in input EQ is used to set the flatness of the input frequency spectrum.
The input frequency spectrum should be flattened as much as possible.
is used to set the downstream signal levels at the DSAN input, which in turn defines
the signal levels at the DSAN input tuners. The nominal DSAN input signal level in
the digital tier should be set to +4 dBmV. Analog carriers should be 6 dB higher in
level. A plug-in input EQ is used to set the flatness of the input frequency spectrum.
The input frequency spectrum should be flattened as much as possible.
Complete the following steps to set the input signal level and frequency spectrum
flatness at the input to the DSAN unit.
1 Connect the cable plant to the Input port (Port 1) on the DSAN unit.
2 Connect the test equipment to the Input port test point (FWD IN -20 dB TP) on
flatness at the input to the DSAN unit.
1 Connect the cable plant to the Input port (Port 1) on the DSAN unit.
2 Connect the test equipment to the Input port test point (FWD IN -20 dB TP) on
the DSAN unit.
3 Measure the signal levels at the lowest frequency and highest frequencies
specified in the system design.
4 Adjust the FWD IN EQ to flatten the frequency spectrum. Adjust the FWD IN
PAD to adjust the level of the input signals.
Note: A FWD IN PAD value of 1 dB and a FWD IN EQ value of 0 dB give the proper
setup for a flat input spectrum with digital signal levels at +4 dBmV (analog
channels are +10 dBmV, or 6 dB higher than digital). Changes to the FWD IN PAD
and FWD IN EQ values will not change the measured results at the FWD IN -20 dB
test point because this test point is located ahead of the input accessories.
setup for a flat input spectrum with digital signal levels at +4 dBmV (analog
channels are +10 dBmV, or 6 dB higher than digital). Changes to the FWD IN PAD
and FWD IN EQ values will not change the measured results at the FWD IN -20 dB
test point because this test point is located ahead of the input accessories.