National Instruments DAQ M Series - Manual (Page 124)

© National Instruments Corporation 12-1 NI 6236 User Manual
12
Triggering
A trigger is a signal that causes an action, such as starting or stopping the
acquisition of data. When you configure a trigger, you must decide how you
want to produce the trigger and the action you want the trigger to cause.
NI 6236 devices support internal software triggering, as well as external
digital triggering. For information about the different actions triggers can
perform for each sub-system of the device, refer to the following sections:
• The Analog Input Triggering section of Chapter 4, Analog Input
• The Analog Output Triggering section of Chapter 5, Analog Output
• The Counter Triggering section of Chapter 7, Counters
Triggering with a Digital Source
Your DAQ device can generate a trigger on a digital signal. You must
specify a source and an edge. The digital source can be any of the PFI,
RTSI, or PXI_STAR signals.
The edge can be either the rising edge or falling edge of the digital signal.
A rising edge is a transition from a low logic level to a high logic level. A
falling edge is a high to low transition.
Figure 12-1 shows a falling-edge trigger.
Figure 12-1. Falling-Edge Trigger
High
Falling Edge Initiates Acquisition
0 V Digital Trigger