National Instruments DAQCard-1200 - Manual (Page 69)

Chapter 5 Calibration
© National Instruments Corporation 5-3 DAQCard-1200 User Manual
When you perform analog input calibration, you must first configure the
ADC for referenced single-ended (RSE) mode and for the correct polarity
at which you want to perform data acquisition. When you perform analog
output calibration, you must first configure the analog input circuitry for
RSE and for bipolar polarity, and you must configure the analog output
circuitry for the correct polarity at which you want to perform output
waveform generation. Refer to the NI-DAQ Function Reference Manual for
PC Compatibles for more details on the
Calibrate_1200 function.