LabVIEW Error: -1074118635 at niDCPower

Updated Apr 22, 2020

Issue Details

  • My PXI(e) Programmable Power Supply generates error 1074118635 in LabVIEW. How Can I fix this?
  • Why do I see error "niDCPower Initiate. vi - Internal serial communication bus failed. Try resetting the device. If the error persists, contact National Instruments"?
  • My PXI(e) Programmable Power Supply is getting stuck in a protective position after this error occurs. How do I resolve this?


This error usually occurs when the power supply encounters a high frequency, common mode power or voltage spike. 
If the device becomes stuck in a protective mode, functionality can be restored by resetting the device.

To prevent the error from occurring, several measures can be taken. These are listed below.


Check Grounding and Connections

Often times, a sudden voltage spike will cause the device to enter a protective state. This may be due to:

  • Voltage peaks between the PXI chassis ground and the isolated source output of the device.
  • Improper grounding of any devices that are a part of the PXI system.
An oscilloscope can be used to monitor the signals between the PXI(e) device and the chassis ground. This will highlight any common mode transient that may be present.


Closing the Output Relay of the Device

PXI(e) Power Supply cards have an output relay that disconnects when the PXI system is powered on. This relay is controlled by the Output Connected Property.
If the relay is open at the beginning of the operation, this error can occur.

By default, this property is set to True, which means that the relay is closed whenever niDCPower Commit or niDCPower Initiate are called. To open the relay: To ensure that the relay is in a closed state when beginning any tests, the niDCPower Commit VI can be used with a Wait function at the beginning of the device's configuration.


Removing Common Mode Transient

A common mode choke can be used to try and remove the common mode transient. When doing this, both leads from the device can run through the same choke. However, the wires should wrap around the choke several times. A diagram of how this can be seen in this article.

Alternatively, a low pass filter can be implemented to help reduce the common mode transient.

Additional Information

There are numerous possible causes for this error so the list above is not exhaustive. If the error persists after trying these troubleshooting steps, contact National Instruments Technical Support.