The NI PCIe-6251 is a 16-bit multifunction DAQ module for PCI Express systems, integrating analog input, analog output, digital I/O, and counter/timer functions into a single card. It delivers 16 single-ended or 8 differential analog input channels at up to 1.25 MS/s per channel, with 7 programmable input ranges from ±0.1 V to ±10 V. Two 16-bit analog output channels support update rates to 2.86 MS/s, while 24 digital I/O lines and two 32-bit counters at 80 MHz provide timing and control capabilities. The NI-PGIA 2 amplifier ensures fast settling and 16-bit precision across the full sample rate, with exceptional channel isolation: -95 dB crosstalk on non-adjacent channels and -75 dB on neighbors. A 100 dB common-mode rejection ratio and 50 ppm accuracy specification support high-fidelity measurements. Six DMA channels minimize CPU overhead during data transfers, while analog and digital triggering with start, reference, and pause functions enable synchronized acquisition. The single 68-pin VHDCI connector accommodates external signal conditioning, and the card fits x1, x4, x8, and x16 PCI Express slots. Operating range is 0 °C to 55 °C.
Technical Specifications
• Analog Inputs: 16 single-ended or 8 differential channels, 16-bit resolution, 1.25 MS/s max (single channel), 1.00 MS/s aggregate, ±0.1 V to ±10 V programmable ranges, 50 ppm accuracy
• Analog Outputs: 2 channels, 16-bit DAC, 2.86 MS/s single-channel, 2.00 MS/s dual-channel update rate
• Digital I/O: 24 lines total; 8 correlated DIO channels; up to 48 TTL/CMOS compatible
• Counters/Timers: Two 32-bit channels at 80 MHz
• Triggering: Analog (10-bit precision) and digital; start, reference, and pause functions
• Bus Interface: PCI Express x1 (v1.0a compliant); compatible with x1, x4, x8, x16 slots
• Connector: One 68-pin VHDCI
• DMA: Six channels
• Dimensions: 4.2 in. × 6.1 in. (full-length) or 3.9 in. × 6.6 in. (half-length)
• Operating Temperature: 0 °C to 55 °C
– Key Features
• NI-PGIA 2 amplifier for high-speed, 16-bit precision measurements
• Minimal crosstalk: -95 dB (non-adjacent), -75 dB (adjacent channels)
• 100 dB CMRR for noise rejection
• DNL correction and overdrive protection on analog outputs
• DMA-based data transfer eliminates CPU bottlenecks
– Compatibility & Integration
Supported by NI-DAQmx and NI-DAQmx Base driver software. Not compatible with Traditional Legacy NI-DAQ drivers. Interfaces with signal conditioning modules via the 68-pin VHDCI connector.
