
Gated Mode
Gated mode is turned on with the
gated
soft-key on the
MODE
screen. The parameters
associated with Gated are set on the
TRIGGER INPUT SETUP
screen called by pressing the
TRIG IN key.
TRIGGER INPUT SETUP:
◊
source: internal
◊
slope: positive
♦
period: 2·00ms
Gate Source
The gate source can be selected with the
source
soft-key to be
internal, external
or
manual.
With
internal
selected the internal trigger generator is used to gate the main waveform; the
duration of the gate is half the generator period, see Internal Trigger Generator section.
With
external
selected the gate duration is from the point (nominally 1·5Volts) on the specified
edge of the signal at TRIG IN until the same level on the opposite edge.
With either
internal
or
external
selected the gate can
also
be opened and closed by the
MAN/SYNC key or remote command; with
manual
selected as the source,
only
MAN/SYNC or
remote command can be used to open or close the gate. With
internal
or
external
selected the MAN/SYNC or remote command gate signal is exclusive-OR’d with the
internal/external signal; with
manual
selected the gate is turned on and off with alternate key
presses/remote commands.
Gate Polarity
If
slope
on the
TRIGGER INPUT SETUP
screen is set to
positive
the gate will open at
the threshold on the rising edge and close on the threshold of the falling edge of an external
gating signal, i.e. the gate signal is true when the TRIG IN signal is high. If the
slope
is set
negative
the gate signal is true when the TRIG IN signal is low.
Sync Out in Triggered Burst and Gated Mode
When Triggered Burst or Gated modes are selected the SYNC OUT source automatically defaults
to
trigger
.
Trigger
is the output of the internal trigger generator when internal triggering or
gating is specified and is a positive-edged version of the actual external signal when external
triggering or gating is selected.
Alternatively, SYNC OUT can be set to
burst done
on the
SYNC OUT SETUP
screen. SYNC
OUT then provides a signal which is low during the waveform burst and high at all other times.
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