Counter Triggering - National Instruments NI cRIO-905x Series User Manual

Table 17. Counter Timing Measurements (Continued)
Measurement
Buffered Position
Buffered Two-Signal Edge Separation

Counter Triggering

Counters support three different triggering actions:
• Arm Start Trigger—To begin any counter input or output function, you must first enable,
or arm, the counter. Software can arm a counter or configure counters to be armed on a
hardware signal. Software calls this hardware signal the Arm Start Trigger. Internally,
software routes the Arm Start Trigger to the Counter n HW Arm input of the counter.
For counter output operations, you can use it in addition to the start and pause triggers.
For counter input operations, you can use the arm start trigger to have start trigger-like
behavior. The arm start trigger can be used for synchronizing multiple counter input and
output tasks.
When using an arm start trigger, the arm start trigger source is routed to the Counter n
HW Arm signal.
• Start Trigger—You can use the start trigger for counter output functions. You can
configure a start trigger to begin a finite or continuous pulse generation. After a
continuous generation has triggered, the pulses continue to generate until you stop the
operation in software. For finite generations, the specified number of pulses is generated
and the generation stops unless you use the retriggerable attribute. When you use this
attribute, subsequent start triggers cause the generation to restart.
When using a start trigger, the start trigger source is routed to the Counter n Gate signal
input of the counter. Possible triggers for counter output operations are a hardware signal.
For counter input functions, you can use the arm start trigger to have start trigger-like
behavior.
• Pause Trigger—You can use pause triggers in edge counting and continuous pulse
generation applications. For edge counting acquisitions, the counter stops counting edges
while the external trigger signal is low and resumes when the signal goes high or vice
versa.
For continuous pulse generations, the counter stops generating pulses while the external
trigger signal is low and resumes when the signal goes high or vice versa.
When using a pause trigger, the pause trigger source is routed to the Counter n Gate
signal input of the counter.
Implicit Timing Support
No
Yes
NI cRIO-905x User Manual | © National Instruments | 65
Sample Clocked Timing
Support
Yes
Yes