Video Test Generator User Guide

802BT/802R Video Test Generator User Guide 133
Analyzing pseudo-random noise in a cable or distribution
system
The following example uses commands to test a connected HDMI/DVI cable or distribution
system.
To analyze pseudo-random noise in a cable or distribution system:
1. Connect the DVI or HDMI cable between the transmit and receive connectors on the
generator.
If you are testing a distribution system connect an access cable to the distribution
center to the transmit connector on the generator and a second access cable to the
receive connector on the generator.
2. Using a terminal emulator, establish a terminal connection with the generator. Refer to
“Setting up a terminal connection with the generator” on page 14.
3. Enter the following commands to configure the generator to output a digital signal
(HDMI or DVI):
SROP 2 4
This removes analog friendly mode and configures the generator to output either a DVI
or HDMI signal depending on the interface hardware the generator is equipped with
(DVI or HDMI).
4. (optional) Enter the following commands to set the status display mode:
SROP 8
5. Enter the following commands to analyze pseudo-random noise in a cable or
distribution system.
FMTL TEST165 // loads the TEST165 format for testing DVI
Note: For HDMI testing load the TEST81 format.
FMTU // applies the TEST165 or TEST81 format to the generator
6. Enter the following commands to configure the pseudo-random noise parameters.
PNSF 0 // selects internal timing source for pseudo-random noise
PNST 1 // specifies QDI-BCM algorithm
PNSA 1 // sets pseudo random noise to be calculated each pixel
PNSM 0 // sets pseudo random noise test to run in auto mode
PNSP 100 // sets pseudo-random noise for 100 “multi-shots”
PNAU // loads the generator with pseudo-random noise settings
Note: The test will stop automatically if configured to run in the single or multi-shot
mode. If you initiate the test in the continuous mode, you will have to enter a carriage
return to halt the test after PNAU is invoked.
7. Enter the following commands to view the results of the test.