Chapter 3
Hardware Overview
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National Instruments Corporation
3-3
Input Polarity and Input Range
The NI 6115/6120 has bipolar inputs only. Bipolar input means that the
midpoint of the input voltage range is centered at zero volts.
You can independently configure each channel for a different input voltage
range.
The software-programmable gain on this device increases its overall
flexibility by matching the input signal ranges to those that the ADC can
accommodate. It has ranges of ±42 V, ±20 V, ±10 V, ±5 V, ±2 V, ±1 V,
±500 mV, and ±200 mV and is suited for a wide variety of signal levels.
By choosing the optimal gain setting, you can maximize usage of the
dynamic range of the ADC, which effectively increases input signal
resolution. Table 3-1 shows the overall input range and precision according
to the gain used.
Caution
The NI 6115/6120 is not designed for input voltages greater than ±42 VDC.
Input voltages greater than ±42 VDC can damage the NI 6115/6120, any device connected
to it, and the host computer. Overvoltage can also cause an electric shock hazard for the
operator. NI is
not
liable for damage or injury resulting from such misuse.