© National Instruments | 3-37
NI 6612 User Manual
Timing Settings
For this type of generation use Implicit timing by calling the DAQmx Timing (Implicit) VI or function.
Triggering Setting
By default, the NI 6612 begins generating the pulses when you call the DAQmx Start Task VI
or function. The NI 6612 can also begin generating pulses in response to a digital trigger.
To use a start trigger, call the DAQmx Start Trigger (Digital Edge) VI or function. Inputs to this
VI or function include:
• Source—To specify which terminal to use as the Start Trigger signal
• Edge—To specify a rising or falling edge.
The following DAQmx Trigger properties configure the Start Trigger:
• Start.Delay, Start.DelayUnits—To set the delay from when the trigger occurs to when the
NI 6612 begins generating pulses. Note: even if the Start.Delay is set to 0, the NI 6612
inserts a minimum delay equal to two ticks of the counter timebase.
• Start.DigEdge.DgFltr.Enable, Start.DigEdge.DigFltr.MinPulseWidth—To enable and
configure a digital filter on the start trigger input. This filter eliminate noise on the start
trigger signal. Refer to Chapter 4,
PFI, for more information.
Buffer Considerations
DAQmx supports configuring and using the waveform buffer in different ways to support a wide
variety of applications. For example, you can configure DAQmx to:
• read data from the buffer once and stop.
• read data from the buffer multiple times (or continuously).
• update the buffer while the device is generating waveforms.
Refer to the Buffering topic in the NI-DAQmx Help for more information.
Other Features
Frequency Division
The counters can generate a signal with a frequency that is a fraction of an input signal. With
frequency division, the NI 6612 receives a signal with frequency, f, and outputs a signal with
frequency, f/N.
For frequency division, use the steps described in
Generating a Waveform with Constant
Frequency and Duty Cycle
. Also:
• Route the input signal, f, to be the counter timebase using the Co.CtrTimebaseSrc DAQmx
Channel property.
• Create the channel in terms of ticks.
To Next Page
Loading...
Need help?
General
