Create a new or edit an existing Data Logging Test Mode
Go to the Test Modes section of FieldLab Desktop and create a new Data Logging Test Mode, or edit an existing Data Logging Test Mode.

Instructions for creating a new Data Logging Test are here: Create a new Data Logging Test Mode
In the Logging Interval pull-down menu, select High Speed

Select the sub-second interval
You can choose to log at 2, 4, 8, 16, 32, 64, or 128 readings per second.

Save the Test Mode
Once you have adjusted all the settings in the Test Mode to your specifications, Save the Test Mode.
Get the new or edited Test Mode onto your FieldLab device.
If this is a new Test Mode, you will need to add it to a FieldLab device: Add Test Modes to a FieldLab.
If you adjusted the settings in an existing Test Mode, you will need to sync the Test Mode with your FieldLab device: Sync Test Modes