Stanford Research Systems SR785, Руководство по эксплуатации и программированию

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Trigger Menu 4-103
SR785 Dynamic Signal Analyzer
When the Analyzer Configuration is Dual Channel, the delay setting affects the Ch2
input. When the Analyzer Configuration is Independent Channels, the delay setting
affects the measurement displayed in Display B.
The triggered time record does not have to start with the trigger event. The time record
can start before the trigger (negative delay) or after the trigger (positive delay). A delay
of 0 starts the time record at the trigger. The Trigger Delay does not apply if the Trigger
Source is Continuous.
The trigger delay can range from -8,000 to +100,000 times the underlying FFT sample
rate.
When a large trigger delay is used, the display may update more slowly since the
acquisition time for each record (time record length plus trigger delay) is noticeably
long.
Command: TDLB (?) {i}
Trigd Source Mode
Set the trigger mode for the source [1-Shot, Continuous]. The Chirp, Burst Chirp, Burst
Noise and Arbitrary sources are all triggered sources. This box is unavailable if the
source is not a triggered source.
When the trigger is set to Auto-Arm, Continuous, the source is output continuously and
this menu box is ignored.
Triggering
The triggered sources are triggered by External triggers.
In the 1-Shot case, the source only triggers on the first trigger after [Start/Reset]. This
same trigger starts the measurement (and waterfall). This is useful when the source
length is very long compared to the measurement time or many measurements are
required to determine the response to a single source output. This allows a sequence of
many measurements to be triggered at the start of a single triggered source output.
In the Continuous case, the source triggers on every trigger, with a minimum trigger
period set by the source length (FFT time record, noise source period or arbitrary source
length). This is useful when the source length is the same as the FFT time record length.
Do not use Ch1 or Ch2 input trigger since the output will not start until a trigger is
received.
Source trigger outputs the source continuously over and over. FFT time records are
synchronized to the source start.
Watch Out For Triggered Sources
If a triggered source is selected (Chirp, Burst Chirp, Burst Noise or Arbitrary), the
triggered FFT measurement phase is stable only if the input signals are derived from the