Product Details

The NI PCI-6221 is a cost-effective M-series multifunction DAQ card designed for PCI bus test and measurement systems. It supports 16 single-ended or 8 differential analog input channels with 16-bit resolution, and the maximum aggregate sampling rate reaches 250 kS/s. It integrates 2 analog output channels with 16-bit resolution and up to 833 kS/s single-channel update rate, 24 TTL-compatible digital I/O lines and two independent 32-bit, 80 MHz counter-timer channels. Users can select programmable input voltage ranges including ±0.2 V, ±1 V, ±5 V and ±10 V to match different sensor output levels. It adopts NI-MCal calibration technology to improve long-term measurement accuracy, and the high common-mode rejection ratio effectively suppresses power frequency noise and interference in general laboratory environments. The onboard 4095-sample FIFO buffer stabilizes continuous data streaming and reduces data loss during multi-channel scanning tasks. The analog output channels can generate adjustable voltage signals within ±10 V range, which supports closed-loop stimulus-response testing compared with PCI-6220 without analog output.

This DAQ card has 37-pin and 68-pin versions for selection, using dedicated signal connectors for all I/O wiring, compatible with matched shielded cables and terminal blocks for low-level signal measurement. It supports digital triggering and flexible clock configuration, and can synchronize 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 sampling, and built-in self-calibration compensates gain and offset drift to maintain stable measurement accuracy for long-running logging tasks.

This multifunction daq card is widely used in laboratory automation, sensor calibration, closed-loop control test, design verification, small batch manufacturing test stations, strain signal acquisition and OEM measurement equipment integration. It supports NI-DAQmx drivers, compatible with LabVIEW, LabWindows/CVI and C/C++ programming environments, so engineers can quickly develop multi-channel acquisition and analog output control programs. As a discontinued legacy M-series DAQ hardware, the PCI-6221 is mainly used for maintenance and spare replacement of existing measurement platforms. It can maintain stable multi-channel 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.