Agilent Technologies N6700 manual Digitizer Function, Programming the Digitizer

4 Operating the Power System

The Digitizer Function

The digitizer function lets you access the enhanced voltage and current measurement capabilities of the power system. You can:

	Adjust the measurement sample rate - to a maximum of 50 kHz.
	Adjust measurement triggers to capture pre-trigger transients.
	Select a measurement window that can attenuate AC noise.
	Retrieve arrays of the digitized current or voltage measurement.
	Synchronize measurements using trigger signals.
	When a remote interface measurement is in progress, the front panel display
NOTE
	may indicate “-- -- -- -- --“. Front panel measurements resume when the remote
	measurement completes.

Programming the Digitizer

Adjust the Measurement Sample Rate

The following figure illustrates the relationship between measurement samples (or points), and the time interval between samples in a typical measurement.

TRIGGER	MEASUREMENT
OCCURS	SAMPLE (POINT)

TIME INTERVAL BETWEEN SAMPLES

ACQUISITION TIME

(TIME INTERVAL X #SAMPLES - 1)

Ripple rejection is a function of the number of cycles of the ripple frequency contained in the acquisition window. More cycles in the acquisition window results in better ripple rejection. You can vary the measurement data sampling rate using the following commands:

Front Panel:	SCPI Command:
Select Measure\Sweep.	For example, to set the time interval
Enter the points and press Select.	to 60µs* with 4096 samples, use:
Scroll to Time Interval, enter a	SENS:SWE:TINT 60E-6, (@1)
value and press Select again.	SENS:SWE:POIN 4096, (@1)

*The time interval is rounded to the nearest 20.48µs interval, which is 61.44µs.

Acquire Pre-trigger Data

The measurement system lets you capture data before, after, or at the trigger signal. As shown in the following figure, you can move the block of data being read into the acquisition buffer with reference to the trigger. This allows pre- or post-trigger data sampling.

70 Series N6700 User’s Guide