By creating a single AOI that encapsulates the control of a single drive, the programmer can save hours of programming by reapplying the same AOI to every single drive. In a system that uses Variable Frequency Drives, it’s not uncommon to see hundreds of such field devices. To further expand on the points above, let’s discuss practical advantages of building AOI through various examples.

Troubleshooting AOIs is difficult | From our experience, the time it takes to learn how to navigate AOIs is well worth the investment in time saved by engineering and maintenance.

However, it becomes extremely inefficient to duplicate large chunks of code AOIs will save a lot of time. It is true that in most cases, code can be copied and pasted.

AOIs are unnecessary | We see a wide range of AOI implementations in the field.

Once you explain how AOIs are implemented to those who will be working with them, they become quite easy to troubleshoot and work with.

AOIs are difficult to work with | Just like with any other programming language, a “function” construct needs to be understood by those who work with it.

Here are these reasons and our arguments against them, It is important to note that although AOIs are a powerful construct, they’ve gained a bad reputation in the eyes of many. They can be used within a PLC program to standardize the implementation of specific code, shorten development time and reduce possible human mistakes when duplicating code. They are custom functions defined by the programmer. In PLC programming, AOIs are exactly the same. By doing so, programmers have the advantage of re-utilizing their function and simplifying the code they build. They are constructs that allow programmers to create custom pieces of code. In other programming languages (Java, C, C++, Python), programmers are taught functions early on.

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