User`s manual

In an indefinite length arbitrary block:

• “#” indicates the data to be sent is in an arbitrary block.

• “0” indicates that an indefinite length block of data is to be sent.

• “8-bit data bytes” is the data (i.e. frequencies) sent to the AFG.

There are eight bytes per frequency list frequency.

• NL ^END means a line feed (LF) is sent with END (EOI) asserted. It

indicates to the AFG that the end of the data block has been reached.

Additional information on arbitrary block data can be found in ANSI/IEEE

Standard 488.2-1987 IEEE Standard Codes, Formats, Protocols, and

Common Commands.

Frequency Points The number of frequencies generated (points) in a frequency sweep can be

from 2 to 1,073,741,824. The default number is 800. The number of points is

set with the

[SOURce:]SWEep:POINts command and applies to sweeps only.

Sweep Spacing The spacing between the frequencies (points) in a sweep can be either linear

or logarithmic as set by

[SOURce:]SWEep:SPACing. Linear sweeps can

start at 0 Hz. Logarithmic sweeps can start at the reference oscillator

frequency/4,294,967,296/npts. The number of waveform points (npts) for

sine waves and arbitrary waveforms is 1, for square waves npts is 4, for

ramp and triangle waves npts is the number of ramp points.

Sweep Direction The direction of the frequency sweep can be up or down. When the

direction is up, the sweep begins at the specified start frequency and stops at

the specified stop frequency. When the direction is down, the sweep begins

at the stop frequency and stops at the start frequency. You must stop (abort)

the sweep before changing direction.

For arbitrary waveforms when the direction is up, sampling begins at the

start frequency and stops at the stop frequency. When the direction is down,

sampling begins at the stop frequency and stops at the start frequency. You

must stop (abort) sampling before changing direction.

Frequency lists begin with the first frequency in the list and end with the last

frequency. There is no directional control.

Chapter 4 Sweeping and Frequency-Shift Keying 157