Specifies whether to use fractional mode for the local oscillator (LO) phase-locked loop (PLL). Fractional mode gives a finer frequency step resolution, but it may result in non harmonic spurs. Refer to the specifications document for your device for more information about fractional mode and non harmonic spurs.

Note The LO PLL Fractional Mode Enabled property is applicable only when using the internal LO.
Note For the PXIe-5831/5832 with PXIe-5653, this property is ignored if the PXIe-5653 is used as the LO source. For the PXIe-5841 with PXIe-5655, this property is ignored if the PXIe-5655 is used as the LO source. For the PXIe-5842, this property is ignored.

To use this property for the PXIe-5830/5831/5832 and PXIe-5842 VST with 54 GHz Frequency Extension, you must first use the Active Channel property to specify the name of the channel you are configuring. You can configure LO1 and LO2 channels by using lo1 or lo2 as the channel string, or set the channel string to lo1,lo2 to configure both channels. For all other devices, the only valid value for the channel string is "" (empty string).

Default Value: Enabled

Supported Devices: PXIe-5644/5645/5646, PXIe-5830/5831/5832/5840/5841/5842

Remarks

The following table lists the characteristics of this property.

Short Name LO PLL Fractional Mode Enabled
Data type ci32.png
Permissions Read/Write
High-level VIs N/A
Channel-based Yes
Resettable Yes
Disabled 1900

The property is disabled.
Enabled 1901

The property is enabled.