National Instruments USB-6421 USB Data Acquisition Device

The USB-6421 (part number: 789887-01) is a USB Data Acquisition Device from National Instrument’s mioDAQ series. Designed to handle even the most demanding test and measurement applications, this USB DAQ is equipped with 16 single ended (or 8 differential) analog input channels. The device also features 2 analog output channels and 16 digital I/O channels. The digital I/O channels of the USB-6421 can be used as triggers, clocks, or I/O for the four onboard counters, or they can be hardware-timed channels up to 10 MHz or static input/output channels. The I/O connector features two 36 position spring terminals.

This USB DAQ device has 4 (32 bit) general purpose counters that quickly adapt to offer support for various frequency and position measurements. These measurement types include pulse width, edge counting, and semi-period. The maximum single-channel sampling rate of the USB-6421 is 250 kS/s. For multichannel operations, the device can achieve an aggregate rate of 250 kS/s- ensuring that data collection across multiple channels is swift and accurate. The USB-6421 mioDAQ device utilizes a USB Type-C connector for bus power. The connectors of the device are secured with screw flanges with a 1.80 lb / in. torque.

The analog output channels of the device can output ± 10 V, with update rates of 250 kS/s/ch. On the other hand, the analog input channels have with four input range choices from ± 200 mV to ± 10 V. The USB-6421 has published APIs and examples for LabVIEW, Python, C/C++, and FlexLogger Lite- which is NI's free data collecting program.

The physical dimensions of the USB-6421 measure 116.7 mm x 177.0 mm x 30.4 mm (4.59 in. x 6.97 in. x 1.20 in.) , and it weighs an easily manageable and portable 590 g (1.30 lb). While in use, the DAQ device should be kept within an operating temperature range of 0 °C to 55 °C. When not in use, it can be safely kept in storage temperatures ranging from -20 °C to 70 °C. The recommended warm-up time is 15 minutes, and it is recommended to have the device calibrated every 2 years.