Ocean Optics External Triggering Options - Manual (Page 8)

External Triggering Options Instructions
8 200-00000-000-01-201401
Once you select an external trigger mode, your computer will appear unresponsive. This
is normal, as the computer is waiting for a trigger. You must apply one more trigger to
the spectrometer after selecting a new trigger mode.
Since this is a level-triggered mode, the delay between the trigger pulse and spectrum acquisition varies,
depending on the speed at which the software polls the line and recognizes it is HIGH, as well as the
amount of time until the start of the next integration period.
External Synchronization Trigger Mode – S2000 and
S1024DW Spectrometers Only
In this edge-triggered mode, the spectrometer is idle until you apply the initial trigger to the spectrometer.
With each trigger, the spectrometer:
1. Stops taking its current scan (if applicable)
2. Transfers data to the software
3. Begins a new scan
4. Integrates until another trigger is applied
In the External Synchronization Trigger mode, the frequency of triggers to the spectrometer determines
the effective integration time. The effective integration time is the time between rising edges of signals
applied to Pin 5 of the J2 Accessory Connector. All other acquisition parameters are set in the software.
The source for the integration clock is the external triggering device itself, such as a periodic TTL signal.
External Synchronization Triggering – Trigger Timing
When to Use External Synchronization Trigger Mode
Use the External Synchronization Trigger mode if you:
• Must synchronize your scans to an external clock source
• Are using a lock-in amplifier
• Are using a chopper