HP 33120A, User Manual

Page: 59 / 118

SYNC Signal
A sync signal output is provided on the front-panel SYNC terminal.
All of the standard output functions (except dc and noise) have an
associated sync signal. For certain applications where you may not want
to output the sync signal, you can disable the
SYNC terminal.
The SYNC terminal can be enabled/disabled from the remote interface only.
•
By default, the sync signal is routed to the SYNC terminal (enabled).
•
When the sync signal is disabled, the output level on the SYNC
terminal is indeterminate (it might be a
TTL
“high” or a
TTL
“low”).
•
For sine , square , triangle , and ramp waveforms, the sync signal is a
TTL
“high” when the waveform’s output is positive, relative to zero
volts (or the dc offset value). The signal is a
TTL
“low” when the
output is negative, relative to zero volts (or the dc offset value).
•
For arbitrary waveforms, a momentary
TTL
“high” pulse (> 200 ns) is
output which corresponds to the first downloaded point in the waveform.
•
For AM and FM , the sync signal is referenced to the modulating
signal (not the carrier). A momentary
TTL
“high” pulse (> 200 ns) is
output at each zero-crossing point of the modulating signal.
•
For the triggered burst mode , a
TTL
“low” signal is output while the
specified number of cycles is output (for the duration of the burst).
After the specified number of cycles has been output, the sync signal
goes “high” until the next burst.
•
For the external gated burst mode , the sync signal is a
TTL
“high”
when the output is positive, relative to zero volts (or the dc offset
value). The signal is a
TTL
“low” when the output is negative, relative
to zero volts (or the dc offset value).
•
For FSK , a momentary
TTL
“high” pulse (> 200 ns) is output on the
transition to the “hop” frequency.
•
For frequency sweeps , the sync signal is a
TTL
“low” at the start of the
sweep (when the start frequency is output) and is a
TTL
“high” at the
end of the sweep (when the stop frequency is output).
•
Remote Interface Operation :
OUTPut:SYNC {OFF|ON}
Setting is stored in volatile memory.
Chapter 3 Features and Functions
Output Configuration
68