Your device uses software calibration to adjust the software scaling of signals read from and produced by your device. Using a precise reference signal, your device measures and calculates scaling constants for analog input and analog output. The scaling constants are stored in nonvolatile memory (EEPROM) on your device. NI recommends that you calibrate your device just before a measurement session but after your computer and the device have been powered on and warmed up for at least 15 minutes. You should allow this same warm-up time before performing any calibration of your system. Frequent calibration produces the most stable and repeatable measurement performance. The device is not harmed in any way if you recalibrate it often.
C Series devices do not self-calibrate or automatically calibrate. You must use a manual procedure to calibrate these devices.