For example, you can run databases, protocol converters, and recipe managers on an IPC, as well as your SCADA and MES software.īut, like any PC, IPCs can require more frequent updates and patches and may not be able to operate effectively for as long as a traditional PLC. The advantage here is that IPCs can run multiple applications-not just the control programs. Frank Burger with system integrator Avanceon says these software-based controllers feature similar programming environments and firmware as a PAC, but they’re hosted on a regular computer platform.
HONEYWELL PLC BASICS PC
The third controller option facing buyers is the industrial PC or IPC.
Using a PLC for these applications would generally require adding hardware modules to perform those types of tasks. That’s why PACs are often used for controlling larger processes and integrating things like safety, motion, distributed I/O, and network communications. PACs also allow tag-based programming, which increases the flexibility and scalability of the controller by allowing tags to be assigned to functions before tying them to specific I/O or memory addresses. But PACs let you focus on writing in the programming language you prefer while they handle memory management in the background. Both PLCs and PACs serve the same general purpose, but PLCs are typically specified for very basic discrete control operations, while PACs tend to be preferred when complex equipment features or automation infrastructures are required.Įxplaining all this a bit further, Nate Kay with system integrator Martin CSI says: Most classic PLCs use a memory-based form of programming, where the addresses are tightly coupled to a physical memory structure.
HONEYWELL PLC BASICS SOFTWARE
After all, with all the software and chip advances that have occurred over the past few decades, unless you’re looking at the simplest controller to handle the most basic control functions, you’re likely looking at a PAC. Though controller suppliers use the term PAC to distinguish these advanced controllers from their more basic PLCs, the boundaries between the two have become somewhat blurred. Basically, this term better reflects the expanded-and still expanding-capabilities of controllers. With all these new capabilities, the PLC became more than just a basic controller, and that’s how the term programmable automation controller-or PAC-came into being. Some of these new functionalities included integrated servo and drive control, network communications, advanced process control, and the ability to handle multiple programming languages. Over the years, suppliers added new capabilities to basic PLCs to address various end user needs. This capability really set the stage for the future of automation and control and many of the advances we’re seeing today.īut just as no technology is static, neither is the PLC. And though PLCs are essentially very basic computers used to control machine functions, they allow engineers to develop, modify, and expand the functionality of control systems through software, rather than hardware changes to the system that were required in the past with electromechanical relays. It’s been a little more than 50 years now since the invention of the programmable logic controller, or PLC. I’m David Greenfield, Director of Content, and today we’re going to look at the controller options facing OEMs and end user automation equipment buyers.
Welcome to Take Five with Automation World.