Using Rtsi Terminals As Timing Input Signals; Rtsi Filters - National Instruments PXI-6238 User Manual

Chapter 10 Digital Routing and Clock Generation

Using RTSI Terminals as Timing Input Signals

You can use RTSI terminals to route external timing signals to many
different M Series functions. Each RTSI terminal can be routed to any of
the following signals.
•
•
•
•
•
•
•
•
•
•
•
Most functions allow you to configure the polarity of PFI inputs and
whether the input is edge or level sensitive.

RTSI Filters

You can enable a programmable debouncing filter on each PFI, RTSI, or
PXI_STAR signal. When the filters are enabled, your device samples the
input on each rising edge of a filter clock. M Series devices use an onboard
oscillator to generate the filter clock with a 40 MHz frequency.
Note NI-DAQmx only supports filters on counter inputs.
The following is an example of low-to-high transitions of the input signal.
High-to-low transitions work similarly.
Assume that an input terminal has been low for a long time. The input
terminal then changes from low-to-high, but glitches several times. When
the filter clock has sampled the signal high on N consecutive edges, the
low-to-high transition is propagated to the rest of the circuit. The value of
N depends on the filter setting; refer to Table 10-2.
NI 6238/6239 User Manual
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
AI Convert Clock
AI Sample Clock
AI Start Trigger
AI Reference Trigger
AI Pause Trigger
AI Sample Clock Timebase
AO Start Trigger
AO Sample Clock
AO Sample Clock Timebase
AO Pause Trigger
Counter input signals for either counter—Source, Gate, Aux,
HW_Arm, A, B, or Z
10-6 ni.com