Appendix A Specifications
DAQCard-1200 User Manual A-2 © National Instruments Corporation
Maximum working voltage
(signal + common mode)........................Negative input/AISENSE should
remain within ±6 V (bipolar) or
–6 to 2 V (unipolar) of AGND
Overvoltage protection...........................±35 V powered on and ±25 V
powered off
Inputs protected......................................<ACH0..ACH7>
FIFO buffer size......................................1,024 samples
Data transfers..........................................Interrupts, programmed I/O
Dither......................................................Available
Transfer CharacteristicsRelative accuracy....................................±0.5 LSB typ dithered,
±1.5 LSB max undithered
DNL........................................................±1 LSB max
No missing codes....................................12 bits, guaranteed
Offset error
Pre-gain error after calibration........10 µV max
Pre-gain error before calibration.....±20 mV max
Post-gain error after calibration.......1 mV max
Post-gain error before calibration....±200 mV max
Gain error (relative to calibration reference)
After calibration...............................0.02% of reading max
Before calibration............................±2% of reading max
Gain ≠ 1 with gain error
adjusted to 0 at gain = 1...................±0.8% of reading max
Amplifier CharacteristicsInput impedance
Normal powered on.........................100 GΩ in parallel with 50 pF
Powered off.....................................4.7 k min
Overload..........................................4.7 k min