JYTEK USB-61210, User Manual

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Operation & Calibration 27
External Digital Triggering
An external digital trigger occurs when a rising or falling edge is
detected on the digital signal connected to the AITG (analog input
trigger) pin. Trigger polarity can be programmed using JYTEK software
drivers.
Figure 3-7: Digital Triggering
3.1.4 Trigger Modes
Analog input supports post, pre, middle, delay, gate, post trigger with
retrigger, and delay trigger with retrigger modes.
Post-Trigger Acquisition Mode (no retriggering)
Post-trigger acquisition is indicated when data is to be collected after
the trigger event, as shown..
Figure 3-8: Post Trigger without Retriggering
WARNING:
Signal level of the external digital trigger signals should be
LVTTL-compatible, with a minimum pulse of 20ns.
Positive-edge (rising)
trigger event occurs
Negative-edge (falling)
trigger event occurs
Time
Ɣ
Operation
initiates
Trigger
N samples Data
Ɣ
Trigger event occurs
Ɣ
Acquisition begins
Ɣ
Acquisition stops
Ɣ
Data transfer to system commences