STATUS LED Indicators

The following table describes the STATUS LED indicators.

Table 3. STATUS LED Indicators
LED Color LED Pattern Indication
Yellow Blinks twice and pauses

The cRIO-904x is in safe mode. Software is not installed, which is the factory default state, or software has been improperly installed on the cRIO-904x.

An error can occur when an attempt to upgrade the software is interrupted. Reinstall software on the cRIO-904x. Refer to Installing Software on the Controller for information about installing software on the cRIO-904x.

Blinks three times and pauses

The cRIO-904x is in user-directed safe mode, or the cRIO-904x is in install mode to indicate that software is currently being installed.

This pattern may also indicate that the user has forced the cRIO-904x to boot into safe mode by pressing the reset button for longer than five seconds or by enabling safe mode in MAX. Refer to the Measurement & Automation Explorer (MAX) Help for information about safe mode.

Blinks four times and pauses

The cRIO-904x is in safe mode. The software has crashed twice without rebooting or cycling power between crashes.

Continuously blinks

The cRIO-904x has not booted into NI Linux Real-Time. The cRIO-904x either booted into an unsupported operating system, was interrupted during the boot process, or detected an unrecoverable software error.

On momentarily

The cRIO-904x is booting. No action required.

Red Continuously blinks

This indicates a hardware error. An internal power supply has failed. Check front-panel I/O and C Series module connections for shorts. Remove any shorts and cycle power the cRIO-904x. If the problem persists, contact NI.

Solid The cRIO-904x internal temperature has exceeded a critical threshold. Ensure the ambient operating temperature does not exceed the specified operating temperature. If the problem persists, contact NI.
— Off

The cRIO-904x is in run mode. Software is installed and the operating system is running.