1-5
IM AQ6376-01EN
Functions
1
2
3
4
5
6
7
8
9
10
11
App
Index
1.2 Measurement
External Trigger Measurement <<See section 4.16 for the operating procedure>>
This function performs measurement in synchronization with an external trigger signal.
The SMPL TRG IN terminal is an input terminal on the TTL level and in positive/
negative logic (which can be set by the <EXT TRIGGER SETTING> key). The SMPL
TRG IN terminal is an input terminal for TTL level, positive/negative logic signals. The
measurement points (wavelength/frequency) are incremented each time edges of input
external trigger signals are detected. Thus, sweeping stops when a number of external
trigger signals equaling the specified number of sampling points is input. (However,
when the REPEAT sweep is performed, the sweep will be repeated until the
STOP
key is
pressed or until trigger signals are no longer input.)
The delay time (from the time when a trigger signal is detected until the time when the
sampling is performed) specific to the instrument is about 20 µs. Supply the trigger
signal at a timing appropriate for the measurement sensitivity. An optional delay time can
be set to this specific delay time. With the DELAY key of the EXT TRIGGER SETTING
key, the 0.0 µs to 1000.0 µs range can be set in units of 0.1 µs.
Note that after the measurement points are set, input trigger signals during the
movement to the next measurement point are ignored. The time varies depending on the
measurement wavelength band and the number of sampling points (sampling intervals).
Since the SMPL TRG IN terminal is pulled up internally, it can be set to the HIGH level
while it is in the open state and to the LOW level while it is in the GND short state.
Sweep Trigger <<See section 4.16 for the operating procedure>>
This function performs a single sweep measurement based on an externally input trigger
signal.
The instrument starts a single sweep measurement by allowing sweep trigger signals on
the TTL level and in negative logic to enter the TRGGER IN terminal at the back of the
instrument.
The signal logic of the sweep trigger input signals is fixed to negative logic, which cannot
be changed.
The pulse width of sweep trigger signals must be 5 ms or more.
The action when entering a sweep trigger is the same as that for the SWEEP key or
SINGLE key.
The sweep trigger function detects sweep trigger signals by polling in certain cycles.
Thus, the time after a sweep trigger signal is input until the sweep starts will fluctuate in
the range of 5 ms.
Trigger Output <<See section 4.17 for the operating procedure>>
This function outputs trigger signals from the trigger output terminal on the rear panel of
the instrument (only during sweeping).
