PXIe Platform Bit Error Rate Tester
|
BERTPXIe-1003/1005
Coherent Solutions Ltd.
Version
1.00
41
To configure the pattern generation settings, click the PPG tab at the left side of the page. The
settings for each channel are displayed, as illustrated below:
8.5.1
Set up the transmitter de-emphasis
The pattern generator features adjustable two-tap, clocked/unclocked output de-emphasis to
respectively compensate for the pre-cursor or the post-cursor inter-symbol interference in the
transmission medium. The generator can be programmed to enable either the pre-cursor de-
emphasis or post-cursor de-emphasis, but not both simultaneously.
De-emphasis on the output channels boosts the high frequency content by the selected
amount. This type of adjustment can be useful for counter-balancing the loss of higher
frequency components in the signal as it travels down a length of coaxial cable.
The PLL must be enabled and locked for the pre-cursor or post-cursor de-emphasis to operate.
De-emphasis of the output waveform is realized by summation of the contributions of a main
tap and the pre-cursor tap. By default, there is no de-emphasis applied upon power-on.
The control of the pre-cursor and post-cursor de-emphasis is available at any data rate. When
both the pre-cursor and the post cursor de-emphasis are available, they are mutually exclusive.
8.5.1.1
Set the cursor and de-emphasis
To set the pre-cursor or post-cursor de-emphasis, take the following steps:
1.
Select an appropriate value from the DE-EMPHASIS drop-down list.
2.
Select
PRE
or
POST
from the CURSOR drop-down list.
