4-45
IM AQ6376-01EN
Mesurement
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App
Index
Explanation
Data measurement or signal sweeping starts when triggered by an external signal.
An external trigger input terminal is located on the rear panel of the instrument. Input
signals are of TTL levels.
SMPL TRIG:
Measurement starts per external trigger signals. You can set
whether the trigger activates on a rising or falling edge of the signal.
Measurement starts approximately 70 µs after the trigger activates.
SWEEP TRIG:
Sweeping starts per external trigger signals. The trigger activates on
the rising/falling edge of the signal. Sweeping starts 5 ms at most after
the trigger activates.
SMPL ENABLE: A single or repeat sweep starts when the external trigger signal level is
low. The sweep is stopped when the signal level becomes high. If the
signal level becomes low again, the sweep starts from the point that it
stopped at.
Signal Logic and Delay Time (for SMPL TRIG)
EDGE
This key is used to set the external trigger signal detection edges.
RISE
The rising edge is recognized as a trigger.
FALL
The falling edge is recognized as a trigger.
DELAY ****.*µs
This key is used to set the delay time between trigger signal edge detection and data
measurement. The setting range is 0 to 1000.0 µs (fine: steps of 0.1; coarse: steps of 1).
For information about the external trigger measurement function, see section 1.2.
Measurement Sensitivity and Corresponding Pulse Width
The measurement sensitivity is determined based on the light pulse width. Select the
appropriate sensitivity level based on the pulse width in the table below.
Sensitivity Name and Corresponding Pulse Width
Sensitivity
setting
CHOP MODE
On-Screen Notation
Corresponding
Pulse Width
(Min.)
Normal
PEAK HOLD
Setting
EXT TIRG
Setting
NORM/HOLD
Invalid
NORM/HOLD P-NORM/HLD
E-NORM/HLD
PEAK: 100µs
EXT: 50µs
NORM/AUTO
NORM/AUTO P-NORM/AUT
E-NORM/AUT
300µs
NORMAL
NORMAL
P-NORMAL
E-NORMAL
1ms
MID
MID
P-MID
E-MID
3ms
HIGH1/CHOP
Valid
HI1/CHOP
P-HI1/CHOP
E-HI1/CHOP
50ms
HIGH2/CHOP
HI2/CHOP
P-HI2/CHOP
E-HI2/CHOP
200ms
HIGH3/CHOP
HI3/CHOP
P-HI3/CHOP
E-HI3/CHOP
2000ms
4.16 External Trigger Measurement