BNC 725 - Manual (Page 34)

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To facilitate time-delay scanning experiments, the delay of the pulse relative to the trigger can be
“swept” or incremented by a specified value each time the channel is triggered. The sweep value
must be positive. The increment resolution is 5 ns. However, the actual delay is rounded to the
nearest 10 ns at full internal clock. For example if the increment is set to 5 ns, the actual delay is
incremented by 10 ns every second trigger event.
The front panel LED for the delayed pulse after trigger will glow green until an input signal is
detected. The LED will be unlit for the delay time and will glow red for the duration time. What
happens next depends upon the channel settings:
Retriggering
enabled? Edge
triggered? The channel LED…
no yes or no remains red (no more triggers accepted)
yes no glows green (waiting for next trigger)
yes yes is off; glows green once input goes low.
To try the delayed pulse mode:
1. Under General Properties, choose 100/64 (low resolution) clock mode for Channels A
and B.
2. Click OK to save the change. A warning may appear listing channels for which the
clock range settings are invalid. Click OK to close the warning. The software will go into
“offline” mode allowing you to adjust the timing settings for the listed channels.
3. In Channel A’s properties screen, select Delayed Pulse After Trigger.
4. On the Delay tab, enter a delay of 1s and duration of 500 ms.
5. On the Triggering tab choose Retrigger N Times and set N=0. Choose Input high (level
trigger).
6. Click Apply.
7. Go “online” and click Program > Program all channels.
8. Click the external trigger button (connected via BNC cable). One second after you push
it, the output of Channel A will go high for 500 ms.
9. The channel LED remains red, indicating it is not ready to trigger. Push the button again.
You’ll see that you cannot retrigger the channel. Click the Reset button on the Channel