Written by Grant Maloy Smith, the data acquisition expert

In this article we will learn about the different types of Digital Data Acquisition (DAQ) Systems, describing them with enough detail that you will:

  • See what the major variants of digital DAQ systems are
  • Learn about how these types differ from each other and why
  • Understand how they can be used and where

Introduction

There is a wide variety of types of digital data acquisition systems (DAQ) on the market today. They are available in a variety of form factors, speed, sample rate ranges, signal input types, and many other criteria. DAQ systems cover a very broad range of measurement applications or acquiring and sampling electrical signals, from general-purpose to very specific, which further influences their designs. 

Although the focus of this article is on Digital data acquisition systems, there are other kinds of data recorders to mention:

  • Digital Data Acquisition
  • Data Loggers
  • Data Recorders
  • Signal Conditioners
  • Oscilloscopes
  • Spectrum Analyzers
  • Vibration Analyzers

Data Acquisition System Types

We can sort digital data acquisition systems types according to several important criteria:

All data acquisition system types mentioned below offer signal conditioning amplifiers (i.e. signal conditioning circuitry) for sampling and collecting data from all sorts of analog signals and analog sensors such as strain gauge, IEPE, thermocouple, RTD, LVDT, voltage, current, etc.

Data Acquisition Systems by Form Factor

One of the most useful ways to sort the wide range of DAQ systems on the market today is by form factor. DAQ hardware is available in a wide variety of sizes, from those you can hold in your hand to benchtop systems and multi-chassis rack-mounting systems. As you would expect, the smallest systems have fewer channels than larger ones.

DAQ systems are available in a variety of form factors, including:

  1. Computer-connected DAQ Modules
  2. Stand-alone Data Acquisition Systems (also called Portable data acquisition systems with a built-in computer)
  3. Rack-mounting Data Acquisition Systems
     

Computer-connected Data Acquisition Modules

DAQ systems that connect to the user’s computer are generally less expensive than those with built-in computers. They can also be smaller and lighter by virtue of not having a computer and its related peripherals, such as one or more hard drives, a keyboard, and a display, for example. 

Dewesoft makes several popular computer-connected DAQ modules:

Series Interface to PC Top Sample Rate/ch Features

SIRIUS modular data acquisition systemsSIRIUS

USB 2.0
EtherCAT
200 kS/s or 1 MS/s Small, with top performance signal conditioning, EtherCAT, and USB output.
SIRIUS waterproof IP67 data acquisition systems
SIRIUS Waterproof
USB 2.0
EtherCAT
200 kS/s Waterproof IP67 DAQ devices with top performance signal conditioning, EtherCAT, and USB output.
SIRIUS XHS high-speed data acquisition system
SIRIUS XHS
USB 3.0
GLAN
15 MS/s Small, with the highest sample rate system available, highest bandwidth, and dynamic range.
DEWE-43A handheld data acquisition systemDEWE-43A USB 2.0 200 kS/s Handheld, 8 universal analog inputs, 8 counters, 2 x CAN BUSx
SIRIUS mini 4-channel data acquisition system
SIRIUS mini
USB 2.0 200 kS/s Very small, USB-powered, 4-channel IEPE, and Voltage data acquisition system.
SIRIUS R4 data acquisition system
R4-HUB
USB 2.0 200 kS/s or 1 MS/s Benchtop accepts up to four SIRIUS signal conditioning slices for a total of up to 64 analog channels.
KRYPTON EtherCAT DAQ modules
KRYPTON
EtherCAT 20 kS/s analog / 40 kS/s digital inputs Tiny single-channel and very rugged single and multi-channel modules, extreme environment performance
IOLITE data acquisition systrems
IOLITE Rack
EtherCAT 20 kS/s analog / 40 kS/s digital inputs Benchtop and rack-mounting, for real-time control applications
IOLITE distributable, EtherCAT data acquisition modules
IOLITE
EtherCAT 40 kS/s Tiny single- and multi-channel, distributable EtherCAT DAQ modules 

Each of these DAQ system models connects to a host PC computer using a USB, EtherCAT, or GLAN (Ethernet) data interface. The host computer needs to run DewesoftX data acquisition software which is included for FREE with all Dewesoft DAQ hardware.

Stand-alone or Portable Data Acquisition Systems

When a computer is added to a DAQ device, it becomes a stand-alone data acquisition system, meaning that it does not require any additional hardware to perform data recording and analysis as a data acquisition system. These systems usually also have built-in displays and keyboards, although these elements can be connected externally as well. Internal data storage is always included.

Dewesoft makes several popular stand-alone or all-in-one data acquisition systems:

Series Top Sample Rate/ch Max Channel Count Features
MINITAURs data acquisition system with built-in computer
MINITAURs
200 kS/s 8 analog
8 counter/encoder
24 digital
1 CAN bus
Very small stand-alone system. Display (optional) and keyboard are separate.
SIRIUS R1DB and R2DB data acquisition systems
R1DB and R2DB
200 kS/s or 1 MS/s 16 analog
8 counter/encoder
24 digital
1 CAN bus
Smallest benchtop unit, configurable with up to two SIRIUS DualCoreADC, SIRIUS HD, or SIRIUS HS DAQ modules. Built-in display, keyboard, and batteries.
SIRIUS R3 data acquisition system
R3
200 kS/s or 1 MS/s 32 analog
16 counter/encoder
48 digital
2 CAN bus
Benchtop unit, configurable with 3 SIRIUS DualCoreADC, SIRIUS HD, or SIRIUS HS DAQ modules.
SIRIUS R4 data acquisition system
R4
200 kS/s or 1 MS/s 64 analog
32 counter/encoder
96 digital
4 CAN bus
Benchtop unit, configurable with 4 SIRIUS DualCoreADC, SIRIUS HD, or SIRIUS HS DAQ modules. The display and keyboard are separate.
SiRIUS R8 high channel count data acquisition system
R8
200 kS/s or 1 MS/s 128 analog
64 counter/encoder
192 digital
9 CAN bus
Large benchtop unit, configurable with 8 SIRIUS DualCoreADC, SIRIUS HD, or SIRIUS HS DAQ modules. Optional built-in display and batteries
IOLITE LX Embedded data acquisition system
IOLITE LX
Up to 40 kS/s Up to 8 IOLITE DAQ slots Embedded data acquisition system with ARM processor and Linux OS

Rack-mounting Data Acquisition Systems

When DAQ systems are going to be installed permanently, for example in a laboratory or test bench, it makes sense to put them in standard 19” rack enclosures. This provides physical protection for the system as well as the cables and is especially useful in high channel count applications.

Dewesoft makes several rack-mounting compatible DAQ systems:

Series Top Sample Rate/ch Max Channel Count Features
IOLITE R12 industrial rack-mountable data acquisition system
IOLITE R12
40 kS/s 12 slots for analog, digital I/O. Industrial EtherCAT compatible data acquisition and control system, configured with up to 19 IOLITE DAQ modules.
R3 rack mountable data acquisition system
R3
200 kS/s or 1 MS/s 32 analog
16 counter/encoder
48 digital
2 CAN bus
Benchtop unit, configurable with 3 SIRIUS DualCoreADC, SIRIUS HD, or SIRIUS HS DAQ modules. 
R8 high-channel-count data acquisition system
R8
with Rack-mount accessory
200 kS/s or 1 MS/s 128 analog
64 counter/encoder
192 digital
9 CAN bus
Large benchtop unit, configurable with 8 SIRIUS Dual-Core, SIRIUS HD, or SIRIUS HS DAQ modules. Optional built-in display and batteries.

Distributed Data Acquisition Systems

What does “distributed” mean? Most engineers are familiar with the classic DAQ system that sits on a lab bench. But what about applications that have a wide array of measurement points located some distance from each other? In the past, these applications could only be handled by using multiple DAQ systems and then attempting to merge and synchronize their data together after the testing.

Today there is a new kind of DAQ system. A distributable data acquisition system capable of locating input modules all-around a factory or other large area or structure. These DAQ systems are designed to have built-in synchronization across all of the measurement units and input channels. They digitize the signals right at the measuring points, sending back digital data to a central computer, EtherCAT master, or even a central database or cloud database.

The example photo below shows how data acquisition systems are distributed over a large area. This distribution of DAQ systems brings several advantages:

  1. The single cable connecting DAQ hardware units for power, synchronization, and data.
  2. Sensor cable lengths are kept to a minimum since DAQ systems are placed close to them. This removes signal noise and improves signal quality overall. 

Krypton DAQ systems distributed on an airplaneKRYPTON DAQ systems distributed on a heavy machinery vehicle

Sample schematic where our Dewesoft KRYPTON and SIRIUS DAQ devices can be distributed on larger test subjects like airplanes, excavators, bridges, etc. The devices are distributed using a single EtherCAT cable between devices which carries synchronization, power, and data.

Dewesoft offers several distributable data acquisition systems:

Series Top Sample Rate/ch Max Channel Count Features
KRYPTON EtherCAT DAQ modules
KRYPTON
EtherCAT 20 kS/s analog  IP67 rugged single and multi-channel DA modules. Offer extreme environment performance. Up to 100m device to device.
SIRIUS modular data acquisition systemsSIRIUS EtherCAT EtherCAT 200 kS/s or 1 MS/s Top performance signal conditioning DAQ modules, distributable via EtherCAT. Up to 100m device to device.
SIRIUS XHS high-speed data acquisition system
SIRIUS XHS
GLAN 15 MS/s Small, with the highest sample rate system available, highest bandwidth, and dynamic range.
IOLITE distributable, EtherCAT data acquisition modules
IOLITE
EtherCAT 40 kS/s Tiny single-channel and very small multi-channel modules, made for industrial applications. Up to 100m device to device.

Data Acquisition Systems by Acquisition Speed

Along with accuracy, sampling speed is one of the most important performance characteristics of any measuring system. 

Included with all Dewesoft systems, DewesoftX DAQ software supports the full range of sample rates that the hardware allows, from extremely slow speed sampling on the range of minutes or even hours between samples), all the way up to 15 million samples per second (per channel!) with SIRIUS XHS DAQ modules.

Here is a top-level overview of Dewesoft DAQ systems by top acquisition speed:

Slow to Medium Medium to Fast Fast Very Fast
Up to 20 kS/s Up to 200 kS/s Up to 1 MS/s Up to 15 MS/s
IOLITE data acquisition systrems
IOLITE Rack
DEWE-43A handheld data acquisition system
DEWE-43A
SIRIUS modular data acquisition systemsSIRIUS HS SIRIUS XHS high-speed data acquisition system
SIRIUS XHS
IOLITE distributable, EtherCAT data acquisition modules
IOLITE
MINITAURs data acquisition system with built-in computer
MINITAURs
SIRIUS XHS high-speed data acquisition system
SIRIUS XHS
 
IOLITE LX Embedded data acquisition system
IOLITE LX
SIRIUS mini 4-channel data acquisition system
SIRIUS mini
   
KRYPTON EtherCAT DAQ modules
KRYPTON
SIRIUS modular data acquisition systems
SIRIUS
   
SIRIUS modular data acquisition systems
SIRIUS EtherCAT
SIRIUS rack data acquisition systems
SIRIUS Rack models
(R1DB, R2DB, R3, R4, R8, R8rt)
   

Dewesoft DAQ systems by top acquisition speed

Slow to Medium systems (100 S/s to 20 kS/s) are typically found in:

  • Process control and machine monitoring applications
  • Real-time control, factory automation
  • Voltage and current monitoring, power plant tests, relay and valve tests
  • General-purpose testing across every industry
  • Civil engineering, structural monitoring

Medium to Fast systems (200 kS/s) are often found in:

  • Noise and vibration (NVH), modal tests, sine processing, structural analysis
  • The road load, combustion analysis, cold and hot weather, and vehicle tests of all kinds
  • Aerospace and military testing of engines, control surfaces, wind tunnel tests
  • Electromotor tests, elevator

Fast systems (1 MS/s) are used for:

  • Dynamic shock, impact, and crash tests
  • Ballistics testing
  • Power analysis
  • Power quality analysis
  • E-mobility

Very fast systems (15 MS/s) are used primarily for:

  • Transient capture applications
  • Impact and crash tests
  • Weapons testing
  • Power analysis
  • Power quality analysis
  • E-mobility

Data Acquisition Systems by Environment Protection or Ruggedness (IP rating)

Rugged data acquisition systems are built to work in very harsh environments. The most important considerations include a wide operating temperature range, the ability to withstand high shock and vibration, and resistance to water, dust, smoke, ice, etc.

Model

Water/Dust Proof Rating

Temperature Operating Range Max. Shock Rating Max. Vibration Rating
KRYPTON EtherCAT DAQ modules
KRYPTON
IP67 -40 to +85° C
-40 to +185° F
100 g, 6 ms, half-sine See technical details
KRYPTON CPU rugged data processing computer
KRYPTON-CPU
IP67 -40 to 70° C
-40 to 158° F
100 g, 6 ms, half-sine See technical details
SIRIUS waterproof IP67 data acquisition systems
SIRIUS Waterproof
IP67 -40 to +60° C
-40 to 140° F
100 g @ 4 ms 50x, half-sine, all axis See technical details
SBOX waterproof data processing computer
S-BOX Waterproof
IP67 -40 to 50° C
-40 to 122° F
100 g, 4 ms, half-sine
50x pos./neg in each axis
See technical details
SIRIUS fanless data acquisition systems
SIRIUS Fanless
IP50 -10 to 40 °C Vibration sweep sinus (EN 60068-2-6:2008)
Vibration random (EN 60721-3-2: 1997 - Class 2M2)
Shock (EN 60068-2-27:2009)
MIL-STD-810D
See technical details
R8 high-channel-count data acquisition system
R8R and R8Rrt
       

Digital DAQ systems by the ruggedness

Data Acquisition Systems With Control Capability

There is a whole new kind of DAQ system available from Dewesoft. So-called data acquisition and control systems. These systems can be used in a real-time control system loop and offer high-speed buffered data acquisition and also stream reduced data to any 3rd-party EtherCAT controllers.

Model Streams data to EtherCAT master Streams high-speed data via USB to Dewesoft system Module slots per chassis Single and multi-channel modules Dual Data Bus capability
IOLITE data acquisition systrems
IOLITE Rack
Yes Yes
(To host PC)
R12 = 12
R8 = 8
Multi-channel only Yes
IOLITE distributable, EtherCAT data acquisition modules
IOLITE
Yes No N/A (multi-channel modules are DIN rail mounted) Yes Yes
IOLITE LX Embedded data acquisition system
IOLITE LX
Yes Yes
(To host PC or Internal Storage)
8 Multi-channel only Yes
SIRIUS RT data acquisition and real-time control system
SIRIUS RT
Yes Yes
(Integrated PC)
8 (up to 128 analog channels) Multi-channel only Yes

Digital DAQ systems by control capability

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