Selecting the Right Data Logger

Product Selection Guide

	Low-Cost Portable Data Loggers	Programmable Data Loggers	Wireless Data Loggers	Embedded Data Logging System
Price in USD	$63–$97	$169–$4,000	$499–$1,999	>$2,500
Measurement	Temperature, Humidity	Temperature, Humidity, Pressure, Thermocouple, Event, Voltage, Any Sensor	Temperature, Humidity, Pressure, Thermocouple, Event, Voltage, Any Sensor	Temperature, Humidity, Pressure, Thermocouple, Event, Voltage, Any Sensor
Topology	Stand-Alone	PC-Based	PC-Based	Stand-Alone
Software	Basic Turnkey	Configurable or Programmable	Configurable or Programmable	Programmable
Custom User Interface	No	Yes	Yes	Yes
Data Storage	< 40,000 Samples	PC Hard Drive	PC Hard Drive	< 512 MB Internal, 4 GB SD Expansion, External USB
Fastest Sampling Interval	10s (6 S/min)	1.25us (800 kS/s)	10us (100 kS/s)	1.25us (800 kS/s)
Size (cm)	9.8 x 2.6 x 2.6	Varies	21.4 x 9.5 x 10.2	18 x 8.8 x 8.8
Display	LED, LCD	PC Monitor	PC Monitor	HMI Connection
Power	Battery	Varies	9 to 30 VDC	Redundant 9 to 35 VDC
Extreme Ruggedness	No	No	No	Yes
	Learn More	Learn More	Learn More	Learn More

Table 1. NI Data Logger Product Selection Guide

Data Logger Topologies

Stand-Alone

Stand- alone hardware can continuously measure and log data without connection to a PC. Application logic occurs on the logging hardware processor. Data storage occurs on hardware with the capability of transferring data to a PC. 

View Stand-Alone Low-Cost Portable Data Loggers

View Stand-Alone Embedded Data-Logging Systems

PC-Based

Operation requires full-time connection to a PC over any appropriate bus technology. Data storage mainly takes place in the PC memory. There is limited to no memory on logging hardware.

View PC-Based Programmable Data Loggers 

Data Logger Software Types

Turnkey

Turnkey software is fixed-functionality software without the ability to scale, configure, or customize beyond its original state. 

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Figure 1. USB-500 application software is shipped with low-cost portable data loggers.

View Turnkey Software

Configurable

Configurable software provides basic functionality out of the box with the ability to add or modify functions, algorithms, and other user-defined steps. It does not require the user to modify software through programming. 

Figure 2. LabVIEW SignalExpress can be used with NI programmable data loggers.

Compare Configurable and Programmable Software Options

Programmable

Programmable software features an open environment where the user can create custom UI, execution logic, signal processing and analysis, and file formats and logging. 

Figure 3. The LabVIEW graphical programming environment offers the ultimate software flexibility.

Compare Configurable and Programmable Software Options

What Should Determine the Best Software and Topology for Your Application?

Consider the following five questions when shopping for a data logger.

1. Can it take the measurements you need now and in the future?
   You should view data loggers as tools for engineers, scientists, technicians, students, and anyone else working in a measurement environment. Selecting data loggers that easily expand can often save you money in the long run because you avoid using multiple pieces of equipment for each project. Modular and expandable systems make it possible for you to purchase only the equipment you need now and buy more later as your needs grow.
   
2. How close is the closest computer resource (PC)?
   It is safe to say that the electronic file from a data logger almost always ends up on a PC. This could be for full-time storage in a database, data processing, charting, or reporting for visual analysis and review. If the signals you are logging can be close to a PC, choosing a PC-based data logger can save you a step in the process by localizing, or even automating, that entire process. USB has usable ranges of 5 m on one cable or about 10 to 20 m with repeaters, and Ethernet has a range of 200 m between hubs and an install base covering most of the planet. The computer in question does not necessarily need to be dedicated to the data logger system. With the multicore processors in PCs today, a decent-sized data logger program can run in the background and cause little to no interruption in normal use.
   
3. What is the environment to which this logger could be exposed?
   For some applications, such as road tests or in-vehicle tests, cabling to a PC may be a problem. In these cases, you can use a laptop or a data logger with embedded storage. Either way, you need to consider environmental specifications such as the operating temperature range, power supply needed by the data logger, and shock and vibration survivability. NI C Series programmable data loggers are built with a sturdy, metal housing and, in some configurations, operate in environments ranging from -40 to 70 °C. They also can sustain shocks up to 30 g.
   
4. How much software flexibility do you need?
   Almost all data loggers come with software. Sometimes it is built into the product, such as the data loggers with onboard memory. Other times it comes as an application for a PC to view live data. Either way, it is important to understand the capabilities and limitations of data-logging software. With data loggers built from C Series hardware, you can select the software that best suits your needs. In addition to the three levels of data-logging software from National Instruments, which offer interactive software with no programming required or a full graphical programming environment, you can program USB C Series data loggers with ANSI C, C++, C#, Visual Basic 6.0, and Visual Basic .NET, which gives you ultimate flexibility when it comes to data acquisition and logging with your data logger.
   
5. Where will this data logger need to be installed?
   Mounting and connectivity is a bigger issue than most people think, and having something as simple as predrilled holes can mean large time savings when it comes to system installation and integration. All C Series multimodule chassis come with multiple mounting options including rack mount, DIN-rail mount, and flat panel mount. Dimensional drawings in both PDF and CAD file versions are online. (Learn more about mounting options under the resources tab on chassis model pages.) 
   

Additional Resources

What Is a Data Logger?
Overview and Comparison of C Series Hardware
Three Levels of Data-Logging Software from National Instruments