National Instruments Data Acquisition Device NI USB-621x - AO Start Trigger Signal; Using a Digital Source

Chapter 5 Analog Output
© National Instruments Corporation 5-5 NI USB-621x User Manual
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
AO Start Trigger 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) PFI <0..3>
•
(USB-6212/6216 Devices) PFI <0..15>
•
(USB-6218 Devices) PFI <0..3>, PFI <8..11>
• AI Start Trigger (ai/StartTrigger)
20 MHz Timebase
100 kHz Timebase
Programmable
Clock
Divider
AO Sample Clock
Timebase
Ctr n Internal Output
AO Sample Cloc
k
PFI
PFI
Sample Clock
Timebase Divisor