Measuring Ocxo Stable Frequency Deviation - National Instruments NI 6608 User Manual

Chapter 2 Device Overview
NI PXI-6608 in Slot 2
of PXI Chassis
10 MHz
OCXO
80 MHz
VCXO
Phase
Lock
Loop
NI PXI-6608 or NI PXI-6602
in Slot 3 of PXI Chassis
10 MHz
OCXO
80 MHz
VCXO
Phase
Lock
Loop

Measuring OCXO Stable Frequency Deviation

NI 660x User Manual
disables its internal clock, then uses the OCXO clock instead, illustrated in
Figure 2-7.
80 MHz Phase Locked to
10 MHz PXI Backplane Clock
10 MHz PXI Backplane Clock
80 MHz Phase Locked to
10 MHz PXI Backplane Clock
10 MHz PXI Backplane Clock
Figure 2-7. OCXO as the 10 MHz PXI Backplane Clock
When you power the NI 6608 device, the OCXO requires adequate
warm-up time to reach stable frequency. Five minutes is adequate warm-up
time for a power-off duration of less than one hour, with maximum
deviation within 20 ppb, or parts per billion, while four hours of operation
is adequate for a power-off duration of up to 90 days.
TIO(0)
PXI CLK10 in
(Driving
10 MHz
Supplied by
OCXO)
TIO(1)
TIO(0)
PXI Star
(Not Used
for
Backplane
Clock)
TIO(1)
2-10
PXI Backplane
10 MHz
Circuit
to
Drive
10 MHz
PXI
Backplane
Clock
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