Product Overview
The National Instruments USB-6221 BNC is a multifunction data acquisition device for USB based systems. It provides 16 analog input channels, 2 analog output channels, 24 digital input and output lines, and 2 counters. The BNC version offers convenient shielded connections for analog signals and is suitable for bench top and laboratory measurement.
The USB-6221 is part of the NI M Series DAQ family. It is used in automated test, laboratory measurement, production verification, and educational applications. The device connects to a laptop or desktop computer through USB and is supported by NI-DAQmx software for configuration and programming.
Analog Input and Output
The USB-6221 BNC provides 16 analog input channels with 16 bit resolution and a maximum sampling rate of 250 kS/s. The input range includes standard voltage levels such as plus or minus 10 V, plus or minus 5 V, and plus or minus 1 V. The analog input system supports hardware timed acquisition, triggering, and multi channel scanning.
The device includes two 16 bit analog output channels for control voltages, setpoints, and waveform generation. The analog output system supports hardware timed generation, which is useful for stimulus response testing and control applications. The BNC connections help reduce noise pickup and simplify connection to shielded cables and sensors.
Digital I/O and Counters
The USB-6221 BNC provides 24 digital input and output lines for logic control, relay driving, and status monitoring. Two 32 bit counters are available for event counting, frequency measurement, pulse generation, and position sensing. The digital and counter functions can be synchronized with analog input and output operations through NI-DAQmx timing features.
This combination allows the device to coordinate mixed signal tasks, such as acquiring analog data while counting encoder pulses or generating a digital trigger. The BNC analog connections and separate digital connections make the device suitable for test benches that use both shielded analog signals and logic level signals.
USB Connectivity and Software
The USB-6221 BNC connects to a host computer through USB. This makes it convenient for bench top and portable measurement setups. The device can be used with compatible cables and accessories for signal connection. Proper shielding and grounding help maintain signal quality in noisy environments.
The device is supported by NI-DAQmx driver software. It can be programmed with LabVIEW, LabWindows/CVI, Measurement Studio, and other NI-DAQmx compatible development environments. NI-DAQmx provides configuration tools for channels, timing, triggering, and scaling. This helps reduce development time for data acquisition applications.
Typical Applications
Bench top analog data acquisition with BNC connections
Analog waveform generation and stimulus response test
Mixed signal automated test systems
Sensor measurement and voltage monitoring
Digital logic control and event counting
Laboratory automation and educational measurement
The USB-6221 BNC provides 16 analog inputs, 2 analog outputs, 24 digital I/O lines, and 2 counters in a USB DAQ device with BNC connectivity. Its mixed signal capability and NI-DAQmx support make it suitable for bench top and laboratory test applications.
