User guide

• Change the ‘centerspread’value: the bitrate remains unchanged, while the
upper and lower frequency changes according to the selected deviation. The
deviation value specifies ½ p-p value.
• Change the ‘downspread’ value: the upper frequency remains unchanged,
while the bitrate is adjusted. The deviation value specifies the p-p value.
For some setups, the I/Q modulator’s range limitations require to use centerspread
instead of downspread and adjust the bitrate (and deviation) accordingly. To ease
the handling of this setup, the SSC Advanced Edit Panel allows to edit the upper,
center, and lower frequency.
If the upper or lower frequency is change, the bitrate will be adjusted according to
the selected deviation. The center frequency corresponds to the configured bitrate.
The adjust buttons allow to adjust the corresponding frequency by the specified
ppm-value.
Please note that both the upper and lower frequency and the frequency adjustment
of all three frequencies are not reflected in the firmware. The GUI just calculates
the resulting bitrate and writes it to the firmware.
The Deviation of the clock rate. The range of SSC deviation are as following:
• Downspread with deviation of 0% … 0.5 %
• Centerspread with deviation of 0% … ± 0.5 %
• Upspread with deviation of 0% … 0.5 %
N O T E
The deviation in Upspread and Downspread is the p-p value while in Centerspread
it is 1/2p-p.
The deviation Frequency. The SCC provides the frequency range of 10 kHz – 100
kHz.
You can click on the corrosponding button to choose among Downspread,
Centerspread and Upspread deviation type. The green LED on the button indicates
the currently selected deviation type.
Jitter Tolerance Tests 8
Agilent J-BERT N4903B High-Performance Serial BERT 417
Deviation
Frequency
Type