User guide

When using lower target BER values, the required measurement time per Input

Timing Setting is getting longer very quickly.

The required measurement time for a target BER of 10

-9

is approximately 338e6

seconds per Input Timing Setting, which is not practicable in a real measurement

setup.

N4876A System Setup Adjustment

The N4876A has to be adjusted to ensure error free operation for all data rates.

This adjustment is required once for a dedicated setup of N4903B, N4876A and

the cable kit being used, and has to be repeated whenever one of these are changed

in the setup or the operating temperature is changed by more than 5

Celsius,

compared to the previous adjustment.

N O T E

When the N4876A is enabled from the N4903B, the jitter amplitude in time is

decreased by a factor of 2 to make the jitter amplitude in UI at the N4876A output

match the setting in UI in the N4903B GUI.

Performing System Setup Adjustment Setting

Follow the given steps to perform system setup adjustment setting:

From the Navigation Menu, select External Instrument(s) and then click

Config sub-menu. The Config window shows a list of all instruments connected

to the N4903B.

Select the external instrument from the given list. For example, here you will

select N4876A.

Click Adjustment... to continue.

A message will pop up which warns you to save the instrument settings before

continuing the auto adjustment process.

9 Solving Problems

490 Agilent J-BERT N4903B High-Performance Serial BERT