Analog Output Timing Signals; Ao Start Trigger Signal; Using A Digital Source - National Instruments USB-621 Series User Manual

Analog Output Timing Signals

PFI
20 MHz Timebase
100 kHz Timebase

AO Start Trigger Signal

© National Instruments Corporation
Figure 5-3 summarizes all of the timing options provided by the analog
output timing engine.
Ctr n Internal Output
AO Sample Clock
Timebase
Figure 5-3. Analog Output Timing Options
USB-621x devices feature the following AO (waveform generation) timing
signals:
• AO Start Trigger Signal
• AO Pause Trigger Signal
• AO Sample Clock Signal
• AO Sample Clock Timebase Signal
Use the AO Start Trigger (ao/StartTrigger) signal to initiate a waveform
generation. If you do not use triggers, you can begin a generation with a
software command.

Using a Digital Source

To use AO Start Trigger, specify a source and an edge. The source can be
one of the following signals:
• A pulse initiated by host software
•
(USB-6211/6215 Devices)
• (USB-6212/6216 Devices)
PFI
Programmable
Clock
Divider
Sample Clock
Timebase Divisor
PFI <0..3>
PFI <0..15>
5-5
Chapter 5 Analog Output
AO Sample Clock
NI USB-621x User Manual