National Instruments NI 6120 用户手册

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Appendix B
Common Questions
© National Instruments Corporation
B-5
Timing and Digital I/O
What types of triggering can be hardware-implemented on the 
NI 6115/6120?
Hardware digital and analog triggering are both supported on the 
NI 6115/6120.
If I’m using one of the general-purpose counter/timers on the 
NI 6115/6120, but I do not see the counter/timer output on the I/O 
connector, what am I doing wrong?
If you are using NI-DAQ or LabWindows/CVI, you must configure the 
output line to output the signal to the I/O connector. Use the 
Select_Signal
 call in NI-DAQ to configure the output line. By default, 
all timing I/O lines except EXTSTROBE* are high-impedance.
What are the PFIs and how do I configure these lines?
PFIs are Programmable Function Inputs. These lines serve as connections 
to virtually all internal timing signals. 
If you are using NI-DAQ or LabWindows/CVI, use the 
Select_Signal
 
function to route internal signals to the I/O connector, route external signals 
to internal timing sources, or tie internal timing signals together.
If you are using NI-DAQ with LabVIEW and you want to connect external 
signal sources to the PFI lines, you can use AI Clock Config, AI Trigger 
Config, AO Clock Config, AO Trigger and Gate Config, and Counter Set 
Attribute advanced-level VIs to indicate which function the connected 
signal serves. Use the Route Signal VI to enable the PFI lines to output 
internal signals.
Table B-1.  Signal Name Equivalencies
Hardware
Signal Name
LabVIEW 
Route Signal
NI-DAQ Select_Signal
TRIG1
AI Start Trigger
ND_IN_START_TRIGGER
TRIG2
AI Stop Trigger
ND_IN_STOP_TRIGGER
STARTSCAN
AI Scan Start
ND_IN_SCAN_START
SISOURCE
ND_IN_SCAN_CLOCK_TIMEBASE
CONVERT*
AI Convert
ND_IN_CONVERT