Note In the following section, any references in the NI-DCPower API to a "source” actually refers to the sink functionality of the electronic load. Likewise, any references to an “output” instead refers to an input.

The PXIe-4051 channels can sink voltage and current in Single Point or Sequence Source mode.

Within Single Point and Sequence Source mode, you can input the following:

  • DC Voltage
  • DC Current
  • Constant Resistance
  • Constant Power

The niDCPower Configure Source Mode With Channels VI defines the Source Mode the PXIe-4051 channel is operating in.

Single Point Source Mode

In Single Point Source Mode, the electronic load applies a single sink configuration when it enters the Running state.

You can then update the sink configuration dynamically (when a channel is in the Running state) by modifying those properties that support dynamic reconfiguration.

Sequence Source Mode

In Sequence Source mode, the electronic load steps through a predetermined set of sink configurations. Each sequence comprises a series of inputs for an NI-DCPower channel.

Sequence Source mode encompasses two types of sequences:

  • Simple sequence—Allows you to define a series of voltage inputs or current inputs and Source Delays for a single channel.
  • Advanced sequence—Allows you to define numerous properties per sequence step, in addition to basic voltage inputs or current inputs and Source Delays, for any number of channels.
    • Note You cannot program both simple sequences and advanced sequences within the same session.

    A channel steps through a sequence without any interaction between the host system and NI-DCPower. Because the host system is not involved in executing the changes between steps of the sequence, the changes between steps in a sequence are deterministic.

    Simple Sequences versus Advanced Sequences

    In Sequence Source Mode, you can use either simple sequencing or advanced sequencing. Each sequencing type has distinct capabilities and each is supported differently.

    Task Simple Sequencing Advanced Sequencing
    How to create Set the Source Mode to Sequence and use the niDCPower Set Sequence VI Set the Source Mode to Sequence; use the niDCPower Create Advanced Sequence With Channels VI, related advanced sequencing functions, and individual NI-DCPower properties
    What you can configure Voltage or current level per step of the sequence, along with Source Delay for each step A wide variety of NI-DCPower properties per step of the sequence
    Channels the sequence applies to Any number of channels Any number of channels
    Controlling the initial state Manually configure the channel(s) before calling the Set Sequence function You can create a Commit step to configure channels to a known state before the sequence runs
    Importing and exporting sequences No capability Can be transferred between sessions with the niDCPower Export Attribute Configuration and niDCPower Import Attribute Configuration VIs
    Note You cannot program both simple sequences and advanced sequences within the same session.

    Refer to the NI-DCPower examples in your application development environment to see how you can program with simple sequences and advanced sequences.

    Sinking Examples

    The following images are VI snippets that you can open as graphical code in LabVIEW. To add a VI snippet to your block diagram, save the image to your computer. Drag the saved image onto a LabVIEW Block Diagram Window. The depicted code will be added to your VI.

    Note The PXIe-4051 does not support a programmable voltage limit. While using a voltage limit as an input to the NI-DCPower examples, you must set the limit to Inf.
    Figure 11. NI-DCPower Sourcing/Sinking Current Example


    Figure 12. NI-DCPower Sourcing/Sinking Voltage Example


    Figure 13. NI-DCPower Constant Resistance and Constant Power Example