National Instruments NI 6612 User Manual

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Chapter 5 Counter Signal Routing and Clock Generation
100 MHz Timebase
The 100 MHz Timebase can be used as the timebase for all internal subsystems.
The 100 MHz Timebase is generated from one of the following sources:
• Onboard oscillator.
• Various signals as shown in Figure 5-1.
20 MHz Timebase
The 20 MHz Timebase also can be used as the Source input to the 32-bit general-purpose
counter/timers.
The 20 MHz Timebase is generated by dividing down the 100 MHz Timebase.
100 kHz Timebase
The 100 kHz Timebase also can be used as the Source input to the 32-bit general-purpose
counter/timers.
The 100 kHz Timebase is generated by dividing down the 20 MHz Timebase by 200.
External Reference Clock
The external reference clock can be used as a source for the internal timebases (100 MHz
Timebase, 20 MHz Timebase, and 100 kHz Timebase) on your device. By using the external
reference clock, you can synchronize the internal timebases to an external clock.
The following signals can be routed to drive the external reference clock:
• RTSI<0..7>
• PFI<0..39>
• PXI_Trigger<0..7>
• PXIe_CLK100
1
• PXI_STAR
1
• PXIe-DSTAR<A, B>
1
To route a signal to the external reference clock, set the DAQmx Timing Property RefClk.Src to
the desired signal name.
The external reference clock is an input to a Phase-Lock Loop (PLL). The PLL generates the
internal timebases.
1
PXIe_CLK100, PXI_STAR, and PXIe-DSTAR<A,B> are advanced terminals. See Filtering NI-DAQmx
Name Controls
in LabVIEW Help for more information on showing advanced terminals.

National Instruments NI 6612 Specifications

General

Brand	National Instruments
Model	NI 6612
Category	Computer Hardware
Language	English