Output Connected Properly Reads True After Calling NI-DCPower Disable VI

Updated Oct 25, 2018

Reported In


  • Power Supply
  • PXI-4132
  • PXIe-4112
  • PXIe-4113
  • PXIe-4135
  • PXIe-4136
  • PXIe-4137
  • PXIe-4138
  • PXIe-4139
  • PXIe-4154


  • LabVIEW


  • NI-DCPower

Issue Details

The documentation for the NI-DCPower Disable VI states that the VI opens the output relay on devices that have an output relay.  I hear the output relay disconnect after calling the NI-DCPower Disable VI.  However, when I read the Output Connected property, it reads TRUE.



If it is necessary to disconnect the output of a DC Power Supply or SMU, set the niDCPower Output Connected property to FALSE as shown below.
Note: Not all DC Power Supplies and SMUs support disconnecting the output.

Another way to disconnect the output of a DC Power Supply or SMU is to call the NI-DCPower Disable VI After calling this VI, the output will be disconnected (by opening the output relay).  However, the Output Connected property will still read TRUE when you read it back. This is to maintain IVI Compliance for NI-DCPower and is expected behavior. 

Additional Information

IVI Class Driver for DC Power Supplies
Test developers can write generic applications to control DC Power Supplies from several instrument manufacturers using the IVI DC Power Supply Class Driver. Refer to the related links for more information about IVI.

Note: Calling the IviDCPwr Disable VI will call into the specific instrument driver's equivalent function (for example, NI-DCPower Disable VI). 

The Output Connected property is not exposed to the IVI DC Power Supply Class Driver API.  Thus, if the Output Connected property was set to FALSE after calling the IviDCPwr Disable VI, it would not be possible to set it back to TRUE without closing and reinitializing the session. Setting the Output Connected property to TRUE allows users to disable, abort, reconfigure, and initiate the power supply without having to close and open a new session.


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