Deciding Which Lines You Want To Monitor - National Instruments 653 Series User Manual

Deciding Which Lines You Want to Monitor

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Table 2-4. Port and Timing Controller Combinations (Continued)
Transfer Possible Port
Width Combinations
16 bits Port 0, Port 1
Port 2, Port 3
32 bits Port 0, Port 1, Port 2, Port 3
You need to specify which of the lines in your acquisition you want to
monitor for changes.
Specify which bits are significant to you by using a software line mask in
the
DIG_Trigger_Config
Digital Trigger Config VI for LabVIEW. In the following example, the user
specifies the mask to detect changes on the two least-significant bits of a
port. Pattern 1 does not have changes in the two bits of interest, and data is
not latched. For pattern 2, however, a change is detected on one of the two
bits of interest, and the value of the entire port is acquired.
Mask
Initial Input Pattern
Input Pattern 1
Input Pattern 2
Figure 2-15. Change Detection Example Settings
function in NI-DAQ C interface, and the
0 0 0 0 0 0 1 1
0 0 0 0 0 0 1 0
0 1 0 0 0 0 1 0
0 0 0 0 0 0 1 1
2-29
Chapter 2 Using Your NI 653X
Timing Controllers
That Can Be Used
Group 1
Group 2
Group 1
No change on specified bits.
Data is not latched.
Change detected,
latch entire port.
NI 653X User Manual