Agilent Technologies E1439 manual SigBwPtr, Be set, Invalid parameter combinations

Agilent E1439 Programmer's Reference

Functions listed alphabetically

	k=.62 for 110 dB bandwidth
	AGE1439_SIG_BW_MAX sets sigBw to the maximum value and the filter bandwidth to the
	minimum.
	AGE1439_SIG_BW_MIN sets sigBw to the minimum value and filter bandwidth to the
	maximum.
sigBwPtr	points to the current value of the sigBw parameter.
Caution	Selecting AGE1439_DECIMATE_ON when sigBw=0 results in aliasing (garbage data) due
	to upper limit of the sampling frequency and, therefore, causes the SETUP_ERROR bit to
	be set.
	Selecting AGE1439_DECIMATE_SHIFT for non-zoomed data is not a useful configuration.
	Comments
	To ensure full alias-free operation the analog anti-alias filter (set by the age1439_input_alias_
	filter function) should be ON unless the application inherently bandlimits the input signal to less
	than fs/2. The analog anti-alias filter has a fixed bandwidth and thus is fully effective only when fs
	≥ 100 MHz. If a slower external ADC clock is used, an additional analog filter of the appropriate
	bandwidth may be required for full alias protection.
	The decimation process used to reduce the output sample rate is driven from a "decimation
	counter" which keeps track of which samples to save and which ones to discard for each of the
	octave bandwidth reduction filter stages. In multi-module systems where synchronous sampling is
	required, the decimation counters in all the modules must be synchronous with each other. This
	condition can be forced by using the age1439_filter_sync function.

The following table lists parameter combinations (see also “age1439_data_setup” on page 90) which result in invalid measurement conditions:

Invalid parameter combinations
resolution	dataType	decimate	sigBw
(bits)
12 or 24	REAL or COMPLEX	OFF or SHIFT	1
12 or 24	REAL or COMPLEX	ON or SHIFT	0
12 or 24	COMPLEX	any	0
24	REAL or COMPLEX	OFF	2
24	REAL or COMPLEX	any	0 or 1
12 or 24	COMPLEX	SHIFT	any

All other combinations are valid.

Example

Here are some bandwidth and sample rate results using the "k" calculation for bandwidth:

fs = 100 MHz default internal ADC clock (all data in MHz)

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