Does a PXIe‑6674T Automatically Override a PXI Chassis Oscillator?

Updated Mar 16, 2026

Reported In

Hardware

  • PXIe-6674T
  • PXI Chassis

Issue Details

When I connect a PXIe-6674T on my chassis timing slot does this automatically replace the chassis internal oscillator with the timing card's internal OCXO oscillator? The documentation states that if a 10 MHz reference is detected on the PXI_CLK10_IN connector, the chassis will replace its internal 10 MHz backplane clock with the external source, but it is not explicitly stated whether installing a PXI timing card automatically triggers this override as well.

Solution

The PXIe‑6674T does not automatically override the chassis oscillator because the module can route multiple possible clock signals to the chassis CLK_REF_IN line. Since no default routing is defined, the chassis cannot assume which reference to use. Therefore, the desired clock source must be explicitly routed through the NI‑Sync driver to ensure the chassis uses the timing card’s reference.

Related Links

Other Support Options

Ask the NI Community

Collaborate with other users in our discussion forums



Request Support from an Engineer

A valid service agreement or active software subscription may be required, and support options vary by country.