DAQ (Data Acquisition) is an important process of collecting the necessary information about the electrical and physical phenomenon happening in the experiment or project. The collected information helps us understand how the experiment goes and what kind of performance the system demonstrates. Data acquisition is performed via sensors, measuring devices, instrumentation, and computers, which together consists of a DAQ (data acquisition) system.
The above diagram shows that a DAQ (data acquisition) system consists of sensors, DAQ device and the computer. The DAQ device performs the functions of signal conditioning and ADC (Analog-to-Digital) conversion. The computer provides the platform to run the application of the DAQ system, which requires the special driver software to be installed on the computer. The sensors or transducers interact with the system under measurement via contact or non-contact ways and convert the physical values, such as temperature or pressure to electrical signals, voltage or current depending on applications. The three function blocks must be connected or interfaced to transmit signals between them. This function is carried out by Data Bus based on protocols, such as RS232, RS485, Ethernet, USB, or other field buses.
Professional DAQ systems are built for specific applications and usually can be very expensive. NI offers different products for various applications and customer needs, such as PC-based systems, CompactRIO system and PXI systems.
In a PC-based measurement and control system, the DAQ system is connected to the PC or laptop via USB or Ethernet. The DAQ systems have two main architectures, multifunction IO devices and CompactDAQ Chassis. With a PC-based DAQ system, we can save time for setup, access to the measurements and change configurations of channels, data rates and output rates with ease. It also allows us to build on the measurement system with NI LabVIEW to automate the measurements, perform complicated analysis and integrate instruments from other vendors.
Multifunction IO DAQ Devices provide combinations of analog I/O, digital I/O and counter/timer functionality in a single device for computer-based systems. The Multifunction I/O devices offer varying channels, sample rates, output rates, and many other special features to meet common data acquisition requirements. The NI Multifunction I/O Devices can be used for industry application as well as automated data collection in laboratory environment for research or design verifications. The included DAQExpress software provides basic measurement and analysis and the NI DAQmx driver provides the ability to create customized automated measurement and control applications via supported NI programming environments and, Python, ANSI C, C#.NET, and MathWorks Matlab software.
- Analog, digital, and counter/timer I/O all-in-one
- USB or PCI/PCIe bus connectivity
- Up to 80 analog input channels, 4 analog output and 4 counters
- Software-selectable input ranges and input channel isolation available
- Multiplexed or simultaneous analog architectures
- Voltage measurements up to 10MS/s per channel
- DAQExpress measurement software included
- DAQmx APIs can be installed for LabVIEW, C, C#.NET, Python, etc.
- Electronics testing
- Design Verification
- Laboratory automation