Specifies whether to use fractional mode for the LO phase-locked loop (PLL).

Syntax

RFMXINSTR_ATTR_LO_PLL_FRACTIONAL_MODE

Numeric Value

Data Type

Access

Applies To

90

int32

Read/Write

Lo

Remarks


Fractional mode provides a finer frequency step resolution, but may result in non harmonic spurs. Refer to the specifications document of your device for more information about fractional mode and non harmonic spurs.

For PXIe-5830/5831/5832, if you want to configure or read on LO1 or LO2 channel, use "lo1" or "lo2" as part of the selector string. You do not need to use a selector string or use "lo1, lo2" as part of the selector string if you want to configure this attribute for both channels. You can also use RFmxInstr_BuildLOString utility function to create the LO String. For all other devices, lo channel string is not allowed.
Note

This attribute is not supported on a MIMO session.

You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read on that signal instance. Refer to the Selector String topic for information about the string syntax.
Note

The LO PLL Fractional Mode attribute is applicable only when using the internal LO.

Note

For PXIe-5831 with PXIe-5653, PXIe-5832 with PXIe-5653, this attribute is ignored if the PXIe-5653 is used as the LO source.

The default value is Enabled.

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

Name

Value

Description

RFMXINSTR_VAL_LO_PLL_FRACTIONAL_MODE_DISABLED

0 (0x0)

Indicates that the attribute is disabled.

RFMXINSTR_VAL_LO_PLL_FRACTIONAL_MODE_ENABLED

1 (0x1)

Indicates that the attribute is enabled.