Software development and testing comprises about half of the control system design and integration effort, so a programming platform that can ease and speed the process is vital. Such PC-based platforms are typically used to program a family of target programmable logic controllers (PLCs), with both the PLC hardware and the programming software provided by the same vendor. Since the programmer's expertise can vary widely, there are important considerations when evaluating software programming platforms including ease of use, embedded training, and easy configuration of features.
As automation applications vary widely, so does the amount of time required to program a PLC or similar device. For ease of use, the PC-based controller programming software platform should include ladder logic as one of its programming languages. Although several other programming languages are sometimes used, ladder logic is the best choice in many applications because it is very orderly and similar to schematic wiring diagrams, making it simple to follow. Using ladder logic and limiting the number of instructions used in the program cuts complexity, making it easy for others besides the original programmer to understand.
The features and functions of several programming platforms can be compared along with their accompanying PLC hardware targets, with users selecting the best combination of both. This is a better approach than evaluating either the PLC family in isolation because picking the best PLC hardware won't pay off if the programming software is too hard to use.
In today's multimedia-rich world, online training documentation and videos are becoming the norm, and should be embedded with the programming platform. Users must evaluate the training materials available online and note that while most have built-in help files, only a few have detailed help instruction with training videos built into the programming platform. These videos are often the quickest way to attain software fluency and execute successful projects.
Software tech support is another consideration. With some software platforms, a yearly service fee costing thousands of dollars is required for anything but limited support, and sometimes an hourly rate for support is added. Other vendors offer free tech support, which can result in substantial savings over the lifecycle of the programming platform.
Data logging and remote access is becoming common today, and the software platform should provide methods to configure these functions, with no custom programming required. These functions should be built-in to both the programming platform and the target hardware to provide secure access, either from the programming platform, or via a browser or a mobile app.
Considering the wide range of automation applications, a software platform that supports a wide range of PLCs, small to large, is important. The programming platform should be easy to use, cost-effective, and acceptable to programmers.
This article was contributed by Automation Direct, Cumming, GA. For more information, click here .