PACs (Programmable Automation Controllers) meet the complex demands of modern industrial automation applications because they combine features of more traditional automation technologies: Distributed Control Systems (DCs), Programmable Logic Controllers (PLCs), Remote Terminal Units (RTUs), and Personal Computers (PCs).
The software built for a PAC is not just integrated with the hardware. It’s also integrated internally: it provides not only an integrated development environment (IDE) for programming but also suite of related programs such as human machine interface (HMI) development.
The IDE is a single software program which handles everything related to control programming, such as compiling, editing, and debugging. A software suite, made up of two or more software applications, offers a similar feel and look in all of them, so that familiarity with one helps you use the others more easily.
The software application in the suite is together work behind the scenes in ways that significantly reduce development time. Common tagging means that definitions and names you setup in one of the suite applications are also used in the others. For instance, if you desire a string variable in the control development software, that same definition will be used in the HMI development software. If you name a digital I/O point in the control software, that name will appear automatically when you are configuring OPC data communications.
According to the ARC Advisory group, usually credited with coining to the term PAC, among a PAC’s defining characteristics are three elements related to software:
• Tightly integrated controller hardware and software. The software that is used with a programmable automation controller is designed specifically for the PAC.
• A single development platform, using a single database and common tagging for tasks development across a disciplines range.
• Programmability using software tools which capable of designing control programs to support process flows across several units or machines.