Solution
This floating behavior is expected for NI devices. We do not specify what the device will read if nothing is connected to the channel. You may also see different results on the channels even if they are on the same device. Some will pull the voltage high for the reading, while others will pull the voltage low. To test out your DAQ card to make sure it is reading correctly do the following:
- Attach a known voltage source to the channel, such as 1.5V battery.
- In Measurement & Automation Explorer (MAX) open up the Test Panels for your device
- Enter values for the Channel Name, Mode, Input Configuration and any other relevant parameter.
- Click Start.
The graph should read the voltage level of the device connected to your DAQ card.