Product Details

The NI PCI-6251 is a high-speed M-series multifunction DAQ card built for PCI bus dynamic test and measurement systems. It supports 16 single-ended or 8 differential analog input channels with 16-bit resolution, single-channel sampling rate up to 1.25 MS/s and aggregate multichannel scanning rate of 1 MS/s. It integrates 2 analog output channels with 16-bit resolution and 2.86 MS/s update rate, 24 TTL-compatible digital I/O lines and two independent 32-bit, 80 MHz counter-timer channels. Users can select seven programmable voltage ranges including ±0.1 V, ±0.2 V, ±0.5 V, ±1 V, ±2 V, ±5 V and ±10 V to match different sensor signal levels. It adopts NI-MCal calibration technology to maintain stable long-term measurement accuracy, and the 100 dB CMRR effectively suppresses power frequency noise and common-mode interference in laboratory and light industrial environments. The onboard 4095-sample FIFO buffer stabilizes continuous data streaming and reduces data loss risk during high-speed multi-channel scanning tasks. Compared with PCI-6250 without analog output, this model adds analog output channels to support closed-loop stimulus-response testing while retaining high-speed sampling performance.

This DAQ card uses a 68-pin VHDCI signal connector for all I/O wiring, compatible with matched shielded cables and terminal blocks for low-level signal measurement. It supports analog triggering, digital triggering and flexible clock configuration. Users can synchronize this card with other NI DAQ hardware via the RTSI bus to build multi-board coordinated test systems. The dual 32-bit counter channels can complete pulse counting, frequency measurement, period capture and incremental encoder signal monitoring. Digital I/O lines can read external status signals and drive low-power TTL circuits for trigger routing and simple interlock control, and part of digital lines support hardware-timed correlated operation. It supports DMA data transmission to reduce CPU occupancy during continuous high-speed sampling, and built-in self-calibration compensates gain and offset drift to maintain stable measurement accuracy for long-running dynamic logging tasks.

This multifunction daq card is widely used in transient signal capture, vibration and shock testing, ultrasonic measurement, closed-loop control verification, high-speed manufacturing test stations, dynamic strain acquisition and OEM high-speed measurement equipment integration. It supports NI-DAQmx drivers, compatible with LabVIEW, LabWindows/CVI and C/C++ programming environments, so engineers can quickly develop high-speed acquisition and analog output control programs. As a discontinued legacy M-series DAQ hardware, the PCI-6251 is mainly used for maintenance and spare replacement of existing high-speed measurement platforms. It can maintain reliable fast scanning and analog output performance, retain mature test workflows and avoid the high cost of rebuilding the whole measurement system. Its operating temperature range is 0°C to 55°C, supporting stable continuous operation in laboratory and light industrial environments.