Configures the VBW settings including VBW Auto, VBW(Hz) and VBW to RBW ratio.

Syntax

int32 __stdcall RFmxSpecAn_SpectrumCfgVbwFilter(niRFmxInstrHandle instrumentHandle, char selectorString[], int32 vbwAuto, float64 vbw, float64 vbwToRBWRatio)

Parameters

NameDirectionTypeDescription
instrumentHandle[in]niRFmxInstrHandle

This parameter specifies the RFmx session refnum. Instrument Handle In is obtained from the RFmxInstr_Initialize function.

selectorString[in]char

This parameter specifies a Selector String comprising of the signal name. If you do not specify the signal name, the default signal instance is used. The default value is "" (empty string).
Example:
""
"signal::sig1"
You can use the RFmxSpecAn_BuildSignalString function to build the selector string.

vbwAuto[in]int32

This parameter specifies whether the VBW is expressed directly or computed based on VBW to RBW ratio. This value is expressed in Hz. The default value is True.

Name

Value

Description

RFMXSPECAN_VAL_SPECTRUM_VBW_FILTER_AUTO_BANDWIDTH_FALSE

0 (0x0)

Specify the video bandwidth in the RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_BANDWIDTH attribute. The RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_VBW_TO_RBW_RATIO attribute is disregarded in this mode.

RFMXSPECAN_VAL_SPECTRUM_VBW_FILTER_AUTO_BANDWIDTH_TRUE

1 (0x1)

Specify video bandwidth in terms of the VBW to RBW ratio. The value of the video bandwidth is then computed by using the RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_VBW_TO_RBW_RATIO attribute and the RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_BANDWIDTH attribute. The value of the RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_BANDWIDTH attribute is disregarded in this mode.

vbw[in]float64

This parameter specifies the video bandwidth when you set the VBW Auto parameter False. This value is expressed in Hz. The default value is 30KHz.

vbwToRBWRatio[in]float64

This parameter specifies the VBW to RBW Ratio when you set the VBW Auto parameter to True. The default value is 3.

Returns

Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. Examine the status code from each call to an RFmx function to determine if an error has occurred.

To obtain a text description of the status code and additional information about the error condition, call the RFmxSpecAn_GetError function.

The general meaning of the status code is as follows:

Value

Meaning

0

Success

Positive Values

Warnings

Negative Values

Errors