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

Syntax

NIRFSA_ATTR_LO_PLL_FRACTIONAL_MODE_ENABLED

Numeric Value

Data Type

Access

Applies To

1150187

ViInt32

Read/Write

N/A

Remarks


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

Note

The NIRFSA_ATTR_LO_PLL_FRACTIONAL_MODE_ENABLED attribute is applicable only when using the internal LO.

Note

For the PXIe-5831 with PXIe-5653 and PXIe-5832 with PXIe-5653, this attribute is ignored if the PXIe-5653 is used as the LO source. For the PXIe-5841 with PXIe-5655, this attribute is ignored if the PXIe-5655 is used as the LO source.

To use this attribute for the PXIe-5830/5831/5832, you must use the channelName parameter of the niRFSA_SetAttributeViInt32 function to specify the name of the channel you are configuring. You can configure the 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 the only valid value for the channel string is "" (empty string).

Defined Values:

Name

Value

Description

NIRFSA_VAL_DISABLED

1900 (0x76c)

The attribute is disabled.

NIRFSA_VAL_ENABLED

1901 (0x76d)

The attribute is enabled.

Default Value: NIRFSA_VAL_ENABLED

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