Hello,
In the SCXI-1313, each channel has a 100:1 high-voltage attenuator. To enable or disable the attenuator, either change the default configuration settings for the SCXI-1313 in Measurement & Automation Explorer or adjust the input limit ranges in your LabView application (AI Config VI). If you want to use the default configuration (the one in MAX), just leave the input limits controls with default values.
When using virtual channels, the input limits configured in the virtual channel configurator are used to set the attenuation circuitry appropriately.
Good luck with your application!