The manual approach to measurements involves an instrument and a device under test (DUT), a human, a pen and paper, and maybe even a look-up chart to convert measurement data. Manually interacting with box instrumentation is common when you are making simple and infrequent measurements. In this situation, there are usually few testing requirements and recording the data is trivial. For example, if you have a need for taking one-off voltage measurements, it makes perfect sense to use a multimeter in a manual fashion. With these types of tests, it takes little time to complete and record the measurement; so investing in an automated solution would not save you any time or money.
As you may have experienced, it is rarely the case that modern test systems require just a single and infrequent measurement be acquired. Often the initial requirements are more complex and/or your application needs change over time. Manual measurements become increasingly complex as system requirements become more challenging. In these situations automated testing solutions can reduce time, cost, and errors. Automation is a PC-based approach that uses software and a bus to control instruments in place of manual interactions. Bus and software technologies have evolved over time making it simpler and more cost-effective to automate box instruments. An automated approach can also address some of the following common challenges that arise when taking manual measurements.
Manually acquiring measurements from box instruments can become repetitive and difficult to reproduce without error. When working with a box instrument, you are most likely writing values down by hand or entering them into a spreadsheet. Consider what you end up with: a notepad or Excel sheet filled with numbers you entered, which is obviously prone to human error, and results that are difficult to reproduce or redo if you need to start over. Now, those results are often just the starting point and they probably aren’t actually the information you need to record your data. You most likely have to analyze the numbers using a look-up table or calculator, which just adds another element of complexity to the manual measurement challenge. Automated software solutions eliminate the inefficiencies of manual repetitive measurements and ensure more accurate test results. Considering how much money you spend on your testing equipment, you want to ensure that you can produce accurate results and deliver them quickly. With an automated instrument control system, you can streamline the entire measurement process and ultimately save time and money because you don’t have to rerun tests as a result of human error.
Most likely, you are using more than one signal or instrument in your measurement system. An example of a system that would require a mixed signal and multiconfiguration is a stimulus response test. This test would require that some signal be sent from instrument number one to a DUT, which would result in a response signal from the DUT to be acquired by instrument number two. Manually interpreting and recording all the data from this test would be challenging to do just once, so you can imagine how time consuming and error-prone it would become if it needed to be done multiple times. With an automated software solution, you can consolidate multiple measurements and instruments into a single system. Software technologies have advanced so that you can now integrate instruments from multiple vendors or with different measurement types into a single system to automate more complex tests.
A test system commonly involves data processing or analysis that dictates some action. Look at the stimulus response test example from above and add the requirement that some alarm be triggered if the resulting signal from the DUT exceeds a particular threshold. This requirement means that a data-driven decision must be made through data processing and analysis of the signal. Manually performing a data-driven decision, such as triggering an alarm, is impossible to do instantaneously and could result in unrecoverable consequences. Automated software solutions offer advanced analysis and signal processing routines so that you can easily implement data-driven decisions in your test systems. You can also ensure that actions are taken quickly as a result of the data to reduce the amount of time between routines. Therefore, you can ensure that your measurement system is producing reliable results and will help you achieve shorter design cycles.
As you begin to acquire more than one data point, storage reporting can become challenging. It takes a lot of time to manually record data, and even one human-injected error can render an entire data record useless. Data rarely just lives in a spreadsheet or on a notepad. Some interpretation of the data must occur and high-level findings need to be surfaced to understand the testing results. It’s challenging to report and share data findings manually because of the amount of overhead and work required to deliver the information. Automated software solutions often take advantage of new technologies that allow you to store large amounts of data on disk or publish data to the cloud. The flexibility to choose how you store your data can simplify how you interpret and report the data to others. With an automated solution, you can publish your data nearly anywhere—from a file on your local disk to the cloud, inline with your measurements, or after your tests are complete. This freedom allows you to interpret and share your results more quickly than would ever be possible with a manual measurement system.
Although manual measurements have their place, automating your measurements offers benefits such as saved time and money. As test system requirements become more complex, challenges associated with taking manual measurements will increase. By automating your measurement solutions, you can drastically reduce challenges such as repetition, data error, multisignal and instrument integration, decision making, storing, and reporting. NI LabVIEW system design software is at the forefront as the leading software platform for automating measurement data and ensures that you deliver better quality test data in a shorter amount of time.
Using LabVIEW to Automate Measurements
LabVIEW is a software environment that provides seamless integration to help you build custom instrument control systems and communicate with nearly any instrument over any bus—everything from box instrumentation to PXI modular instruments. With LabVIEW, you can consolidate your measurements in one environment and select from a comprehensive suite of math and signal processing libraries to analyze your data and make complex data-driven decisions. Additionally, you can visualize your results through custom user interfaces and choose how you want to store or report your findings.