User`s guide

Agilent X-Series Signal Generators User’s Guide 277
Digital Signal Interface Module (Option 003/004)
Operating the N5102A Module in Output Mode
This error is reported when the output FIFO is overflowing in
the digital module. This error can be generated if an external clock
or its reference is not set up properly, or if the internal VCO is
unlocked.
806 Digital module output FIFO underflow error; There are not enough samples being
produced for the current clock rate. Verify that the digital module clock is set up
properly.
This error is reported when the output FIFO is underflowing in the digital
module. This error can be generated if an external clock or its reference is not
set up properly, or if the internal VCO is unlocked.
2. If the port configuration is parallel or parallel interleaved, using an IQ signal type, press the
Clocks Per Sample softkey.
Notice that multiple clocks per sample can be selected. Some DACs require the ability to clock
multiple times for each sample; having a clocks per sample value greater than one reduces the
rate by a factor equal to the selected number of clocks per sample. The sample rate is viewed on
the first- level and Data Setup softkey menus.
3. Select the clocks per sample value to fit the test.
4. Press the Clock Source softkey.
From this menu, select the clock signal source. With each selection, the clock routing display in
the signal generator clock setup menu will change to reflect the current clock source. This will be
indicated by a change in the graphic.
5. Select the clock source.
If External or Device is Selected
Press the Clock Rate softkey and enter the clock rate of the externally applied clock signal.
NOTE The clock phase and clock skew may need to be adjusted any time the clock rate
setting is changed. Refer to
“Clock Timing for Phase and Skew Adjustments” on
page 264.
For the External selection, the signal is supplied by an external clock source and applied to the
Ext Clock In connector. For the Device selection, the clock signal is supplied through the Device
Interface connector, generally by the device under test.
If Internal is Selected
Using an external frequency reference, the N5102A module generates its own internal clock signal.
The reference frequency signal must be applied to the Freq Ref connector on the digital module.
a. Press the Reference Frequency softkey and enter the frequency of the externally applied
frequency reference.