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Power a PXI Express Chassis without Embedded Controller

Updated Apr 19, 2023

Reported In


  • PXIe-1062Q

Issue Details

When I try to power on my PXI Express chassis, it does not power on without a controller installed. I also do not hear the switch being pressed. Is something wrong?


Commonly you can't turn a PXIe chassis ON without an embedded controller, the switch on an NI PXIe chassis is a software switch, unlike a hardware latch on previous PXI systems. This is the reason why you do not actually hear the power button when you press it to turn it on. With a software switch, the chassis will not power on unless there is a controller in the chassis.

You can turn ON/OFF your PXIe chassis if it has an Inhibit Switch in the rear panel. You need to move the switch from Default position to Manual Mode to bypass the controller and enable the power supply. Then you can power ON the chassis. If you want to power off the chassis, you can use the Inhibit signal (active low) on pin 5 (see image below) of the Remote Inhibit and Voltage Monitoring connector to power off the chassis.

You can check the article below to verify if your PXIe chassis supports the Inhibit modes. 

​Remote Inhibit, Voltage/Fault Monitoring, and Remote System Monitoring on PXI Chassis


Additional Information

If you need to test the voltage lines of the PXIe chassis, but you don't want to plug in the controller, you can verify the integrated LED in the Power Inhibit Switch.  
  • If the inhibit switch LED is steady green (not flashing), the chassis is powered on and operating normally.
  • If the inhibit switch LED is flashing green, the air-intake temperature has exceeded the chassis operating range.
  • If the inhibit switch LED is flashing red, the power supply outputs are not within voltage regulation requirements.
  • If the inhibit switch LED is steady red, the system fans or power supply fan has failed. The remaining fans will automatically be driven high.
Note: Check the Specifications Manual of your chassis to ensure the above behavior.