Data Acquisition System refers to an integrated system that automatically collects conditioned electrical or non-electrical signals from sensors and other test equipment, then transmits them to upper computers or servers for analysis, processing, monitoring, and storage.

Technical White Paper: Building a Data Acquisition System

Technology is a rapidly iterating cycle. The following white paper analyzes and summarizes technical trend outlook reports from multiple data acquisition equipment providers, covering five aspects: I/O micro-innovation, Moore's Law in data loggers, fiber optic data acquisition and transmission, ultra-stable systems, and massive data management, to explain the key technical points required for building a next-generation data acquisition system.

Technical White Paper: Data Acquisition Technical Points

Measurement noise, which refers to any redundant signal added to the measurement signal, has always been a headache for engineers when implementing data acquisition applications. 1. Choose the right sensor: Common voltage sensors may not be suitable for complex testing environments, in which case current loop sensors, sensors with built-in conditioning, or even digital sensors can be considered. 2. Proper placement and shielding: There are two general principles—the noise source should be as far away as possible from the data acquisition equipment, cables, and sensors, while the data acquisition equipment should be placed as close as possible to the sensors. 3. Filtering techniques: Choose between hardware filtering and software filtering based on the actual situation.

NI CompactRIO monitoring equipment is rugged modular hardware with data processing capabilities for connecting to sensors installed on motors, pumps, fans and any other field assets. NI CompactRIO provides industrial interoperability, integrating ruggedness, connectivity and signal conditioning functions into modular analog and digital I/O that can be directly connected to any sensor or signal, helping companies cost-effectively monitor various assets in real time and provide real-time alarms.

Resolution usually refers to the smallest part that the maximum signal can be divided into after sampling. For example, with a data acquisition card equipped with a 12-bit analog-to-digital converter (ADC), when the input voltage range is ±10V (i.e., Vpp=20V), the minimum voltage it can resolve is 20V/(2^12)=4.88mV. The concept of accuracy refers to the absolute value of the maximum deviation between the measured value and the "true" value. The signal in the entire data acquisition system is affected by errors such as reference drift over time and temperature, random errors, nonlinear errors, gain errors, etc. The combined impact of these factors on the measurement results is what we call measurement accuracy. In short: accuracy describes how accurately the ruler measures, while resolution describes how fine the smallest scale on the ruler is.