Data acquisition
I’ve written a series of posts on test engineering which are listed in order here. In previous posts I covered the test system design process, sources of noise, and noise suppression techniques. If you’ve been reading the posts in order, you will by now have some knowledge of how to design a test system and select system components to reduce noise in a circuit. In this post I will discuss the next step: acquiring and analyzing data.
The purpose of a test system is to determine if a Device Under Test (DUT) meets the test specifications. This requires data. A DAQ is used to digitize signals and convert it to data.
What is a DAQ? A DAQ is a device that digitizes signals and converts them into data which can be processed and analyzed by a computer, as seen in Figure 1. A DAQ consists of analog and digital inputs and outputs (IO) which form the interface between the DAQ and the physical world. The DAQ uses software drivers to communicate with the computer over USB or Ethernet and provides APIs to enable programs to access the digitized data.
Why is a DAQ needed? A computer doesn’t work with voltage/current signals, it works with files and binary data. A DAQ converts real world signals into digital data that can be processed by computers.
How does a DAQ work? A DAQ uses analog to digital converter chips (ADCs) to sample a signal at a set…
