Figure 10-4. filter example – National Instruments DAQ M Series User Manual
Page 119

Chapter 10
Digital Routing and Clock Generation
10-10
ni.com
The filter setting for each input can be configured independently. On power
up, the filters are disabled. Figure 10-4 shows an example of a low to high
transition on an input that has its filter set to 125 ns (N = 5).
Figure 10-4. Filter Example
Enabling filters introduces jitter on the input signal. For the 125 ns and
6.425 µs filter settings, the jitter is up to 25 ns. On the 2.55 ms setting, the
jitter is up to 10.025 µs.
When a PFI input is routed directly to RTSI, or a RTSI input is routed
directly to PFI, the M Series device does not use the filtered version of the
input signal.
Refer to the KnowledgeBase document, Digital Filtering with M Series, for
more information about digital filters and counters. To access this
KnowledgeBase, go to
ni.com/info
and enter the info code
rddfms
.
1
2
3
1
4
1
2
3
4
5
RTSI, PFI, or
PXI_STAR Terminal
Filter Clock
(40 MHz)
Filtered Input
Filtered input goes high
when terminal is sampled
high on five consecutive
filter clocks.