National Instruments 779631-01 PXI Multifunction I/O Module

The part number 779631-01 from National Instruments is the identifying part number for the PXI-6251 PXI Multifunction I/O Module. The 779631-01 PXI Multifunction I/O Module features 16 analog input channels that can be configured as either 8 differential or 16 single-ended inputs. Each channel is equipped with a 16-bit analog-to-digital converter (ADC), ensuring high-resolution signal acquisition. The input ranges are programmable, offering options from ± 0.1 V to ± 10 V to accommodate various signal levels. The maximum sampling rate is 1.25 MS/s for single-channel measurements and 1 MS/s aggregate for multichannel measurements, providing flexibility and high-speed data acquisition.

The device guarantees no missing codes with differential nonlinearity (DNL) and integral nonlinearity (INL) that meet strict performance standards. It supports a small signal bandwidth of 1.7 MHz and features an input impedance greater than 10 GΩ when powered on. The module also includes overvoltage protection up to ±25 V for up to four analog input pins, ensuring safe operation under various conditions. 

The 779631-01 PXI Multifunction I/O Module includes two analog output channels, each with a 16-bit digital-to-analog converter (DAC). These outputs can generate signals within ranges of ± 5 V, ± 10 V, or an external reference range set on APFI 0. The maximum update rate is 2.86 MS/s for a single channel and 2 MS/s for both channels, ensuring fast and accurate signal generation. The outputs have a settling time of 2 µs for a full-scale step to within 15 ppm (1 LSB).

The device provides 24 digital I/O lines, including 8 lines on port 0 and 16 programmable function interface (PFI) lines. These lines can be individually programmed as inputs or outputs and support static digital I/O operations. The digital I/O lines are TTL compatible and can handle input voltages up to ± 20 V on up to two pins. The 779631-01 PXI Multifunction I/O Module also features two 32-bit general-purpose counters/timers capable of performing edge counting, pulse generation, frequency measurement, and more. The counters support various input and output applications, including position measurements using quadrature encoders and pulse train generation.