NI-DCPower contains high-level VIs and functions that set most of the properties and attributes in the NI-DCPower API.

Some properties and attributes are not accessible through the high-level VIs and functions. You must set the values for these properties and attributes using the appropriate property or attribute.

Accessing Properties in LabVIEW

In LabVIEW, properties are accessed through the NI-DCPower property node. To access properties in LabVIEW, complete the following steps:

  1. Open a VI.
  2. In the block diagram view, navigate to the NI-DCPower palette.
  3. Add the property node icon to the block diagram.
  4. Left-click the property node, and select the property that you want to use.
  5. To add additional properties, resize the property node. To resize the property node, drag the resizing handle at the top or bottom of the node and release the mouse button.

When to Use an Active Channel

The Active Channel property defines the channels that channel-based properties apply to. The Active Channel is listed first in the property node.

You must pass an Active Channel in any of the following cases:

  • For multichannel sessions, if you want to configure the channels differently from one another.
  • For multichannel sessions, when reading a property where multiple channels may have different values for that property.
  • For multichannel sessions where the channels span multiple physical instruments, if you are reading any instrument-based properties; in this case, pass the instrument name to Active Channel rather than a channel name.

You do not need to pass an Active Channel, or can pass an empty string, in any of the following cases:

  • If the properties you are using are neither channel-based nor instrument-based
  • If your session includes only one channel
  • If you want to configure all channels in a multichannel session identically
  • If you want to read a property from all channels when all channels have the same property value or from an instrument-based property

Accessing Attributes

In C and Visual Basic 6.0, access the attributes with the Get Attribute and Set Attribute functions. The Get and Set Attribute functions exist for each supported data type in NI-DCPower.