Configuring Active Channels (LabVIEW)

To set or get certain parameters and properties you must specify an active channel using the Active Channel property or the active channel parameter of a VI. Such parameters and properties are referred to as channel-specific parameters and properties. An active channel is one of many entities which share the same channel-specific parameters and properties. Such entities are segments, receive channels, space-time streams (or spatial streams) and combinations of a segment, receive channel, and a space-time stream and users for a multiple-input multiple-output OFDM signal conforming to the IEEE Standard 802.11n-2009, IEEE Standard 802.11ac-2013, IEEE P802.11ah/D1.3, IEEE Standard 802.11af-2013, or IEEE P802.11ax/D6.0.

You must set the Active Channel parameter or property for channel-specific parameters and properties only when you set the Standard property to 80211N MIMOOFDM, 80211AC MIMOOFDM, 80211AH MIMOOFDM, 80211AF MIMOOFDM, or 80211AX MIMOOFDM. You must specify a valid active channel string. The following table lists the various valid channels for different standards. The following table lists the various valid active channel strings for different standards.

Note  Square brackets ([]) indicate optional elements.

Note  When you set the Standard property to 80211A/G/J/P OFDM, 80211B/G DSSS, or 80211G DSSSOFDM, you must set the Active Channel property or parameter to "" (empty string) or NULL.

Active Channel Syntax to Set Properties

Use the Active Channel property on the property node to configure the properties of a channel. For example, the following block diagram shows how you can set the spectral mask reference level to -70 dBm/Hz for channel1 and -71 dBm/Hz for channel2. The toolkit sets the spectral mask reference level for channel0 and channel3 to the default values.

To set the same value on multiple channels, use an active channel to indicate a list of channels that you want to configure. The following block diagram shows how you can configure channel1 and channel2 to have a spectral mask reference level of -70 dBm/Hz.

You can also use an active channel to indicate the range of channels that you want to configure. The following block diagram shows how you can configure channel0, channel1, channel2, and channel3 to have a spectral mask reference level of -70 dBm/Hz.

If you set the active channel to "" (empty string) and configure a channel-based property, the toolkit sets this property to the configured value for all the channels. In the following block diagram, the toolkit sets the spectral mask reference level to -70 dB for all the channels.

If you specify an active channel, you can configure only channel-specific properties for the specified channel. The toolkit returns an error if you configure non-channel specific properties.

Active Channel Syntax to Get Properties

You can read multiple properties for an active channel on one instance of the property node, as shown in the following block diagram.

Use a stream active channel string to configure the active channel for stream-based properties.

You must specify an active channel string for each channel to read multiple properties. The following block diagram shows how to specify the active channel for each channel to read the RMS EVM.

You can also use a For Loop to read properties for multiple channels.

If you specify an active channel, you can read only channel-specific properties for the specified channel. The toolkit returns an error if you attempt to read non-channel-specific properties.