National Instruments 779512-01 Multifunction I/O Device

The part number 779512-01 from National Instruments is the identifying part number for the PCIe-6251 Multifunction I/O Device. This module is available in PCI/PCIe/PXI/PXIe/USB configurations. The module has 8 differential or 16 single ended analog input channels with a maximum sampling rate of 1.25 MS/s. To convert the analog signal to digital for further processing, the module has a 16-bit analog to digital converter. The input voltages of the analog channel are in the range of ±0.1 V, ±0.2 V, ±0.5 V, ±1 V, ±2 V, ±5 V, and ±10 V with a CMRR ratio of 100 dB. 

The device has an input impedance of >10 GΩ in parallel with 100 pF when the module is functioning and 820 Ω when the device is in the OFF state. The input FIFO size of this module is 4,095 samples with a Scan list memory of 4,095 entries. To provide data transfers from one non-contiguous block of memory to another using a series of smaller contiguous-block transfers this module relies on the DMA (scatter-gather) function. It also supports interrupts and programmed I/O for data transferring. 

This module has an overvoltage protection range of ±25 Volts for up to four AI pins when the device is operational and ±15 V for up to four AI pins when the device is OFF. The input current during overvoltage condition is ±20 mA maximum/AI pin. The module features 1 Analog trigger channel with Start Trigger, Reference Trigger, Pause Trigger, Sample Clock, Convert Clock, and Sample Clock Timebase functions. 

To produce an output the 779512-01 Multifunction I/O Device has 2 Analog outputs with a resolution of 16 bits and a single channel sampling rate of 2.86 MS/s. The output voltage range of the module is ±5 V, ±10 V, ± external reference on APFI 0 with an output drive current of ±5 mA. The output FIFO size is 8,191 samples shared among the channels used. The module has two 32-bit counter/timers with counter measurements of Edge counting, pulse, semi-period, period, and two-edge separation. The Internal base clocks of the module have frequencies of 80 MHz, 20 MHz, and 0.1 MHz.