HP 33120A, User Manual

Page: 75 / 118

To Select Burst Modulation
•
The
Burst
annunciator turns on when burst modulation is enabled.
•
Only one modulation mode can be enabled at a time. When you
enable the burst mode, the previous modulation mode is turned off.
•
Front-Panel Operation : Enable burst modulation before you set up
the other modulation parameters. Press
Shift Burst
to output the
burst using the present settings for the carrier frequency, output
amplitude, and offset voltage.
•
Remote Interface Operation : To ensure proper operation, you should
enable the burst mode after you have set up the other modulation
parameters.
BM:STATe {OFF|ON}
Burst Carrier Frequency
The carrier frequency defines the repetition rate of the burst waveform
in the triggered and external gated modes. In the triggered mode, the
number of cycles specified by the
burst count are output at the frequency
of the carrier signal. In the external gated mode, the carrier frequency is
output when the external gate signal is true (
TTL
high).
Keep in mind that the carrier frequency is different than the “burst rate”
which specifies the interval between bursts (triggered mode only).
•
Carrier frequency: 10 mHz to 5 MHz (100 kHz for triangle and ramp).
The default is 1 kHz . You can use sine, square, ramp, triangle, or
arbitrary waveforms for the carrier waveshape.
•
Be sure to note the restrictions for carrier frequency and
burst count shown on the following pages.
Chapter 3 Features and Functions
Burst Modulation
84