Agilent Technologies N4962A, User Manual

Page: 59 / 88

Operation
Serial BERT 12.5 Gb/s User Guide 59
4.7 Basic BER Measurement
The N4962A can quickly be used for basic BER measurements as follows:
connect the OUT/OUT ¯¯¯ ports to the DUT input, connect the IN/IN ¯¯ ports to the
DUT output, use the internal clock, power the system, enable the PRBS output,
adjust the detector clock phase, and turn on the error detector.
When connecting the OUT/OUT ¯¯¯, and IN/IN ¯¯ ports, use a short 50 Ω coaxial
cable. To test single-ended DUTs, terminate the OUT ¯¯¯ and IN ¯¯ ports with 50 Ω
terminations.
• Connect TX CKO to TX CKI with coaxial cable (included; default)
•
Connect RX CKO to RX CKI with coaxial cable (included; default)
•
Connect OUT to DUT input with short 50 Ω coax cable
• Optionally connect OUT ¯¯¯to DUT input ¯¯¯¯ with short phase- balanced 50 Ω
coax cable
•
Connect DUT output to IN with short 50 Ω coax cable
•
Optionally connect DUT output ¯¯¯¯
to
IN ¯¯ with short phase- balanced 50 Ω
coax cable
Add appropriate attenuation or gain to DUT output, output
¯¯¯¯ signals
•
Terminate all unused RF connectors with 50 Ω terminations
• Turn on the power switch from the back panel
•
Adjust the DUT for the best chance for error-free operation (turn
attenuators off, etc)
•
Press the Data Path > Select Path button and select Enabled
•
If the DUT is inverting, press the Data Path > PRBS ¯¯¯¯ button to invert
the output
•
Press the Display > Scroll ↓ button and select Ø
•
Press the Adjust > Config State + button to auto-select the detector
phase
•
Observe the Error ε light (should remain off, indicating no errors
detected)
•
Press the Receiver > On button and ensure the light is on
•
Press the Display > Scroll ↑ button and select ε time (sec) (should be
increasing)
•
Press the Display > Scroll ↑ button and select BER
• Press the Receiver > On button and ensure the light is off when
complete