What should you consider when choosing a PLC design/setup for a renewable energy project (solar and/or storage)?
There aren't many different options you typically buy the software that goes with your PLC.
This software is used to develop, configure or edit the logic that will go in the PLC. Most PLCs have software that you either have to buy separately or that comes with the controller purchase. It all depends on the specific OEM and model you choose. Some PLCs have these modules built in, while others have the option to add on modules depending on the kinds of connections you need.
From there, PLCs can have additional modules for serial communication, ethernet communication, and other types of hardwired I/Os. The main module is the controller module, where the logic runs to and from. Most PLCs are module-based, meaning that they have a base with slots that the different modules fit into. What are the main features of a PLC? What does a PLC usually include (hardware/software) and what options are available? We typically recommend using a dedicated hardware PLC like the GE, Ovation or Allen-Bradley when an RTAC doesn't completely fill the advanced control requirements, or when you need extremely fast response control.Īll of these controllers are industrially hardened to withstand rugged conditions like a substation or outdoor SCADA rack. However, RTACs do have some limitations in terms of advanced control capabilities. They are able to run and execute logic for nearly any application, sending out commands to control plant devices and regulating output. SEL RTACs are powerful multipurpose controller/communication devices that can fulfill many roles at a solar PV plant. RTAC stands for Real Time Automation Controller. While not strictly PLCs, RTACs by Schweitzer Engineering Laboratories (SEL) can be used to perform the same or similar functions. They are open architecture, which means they are not limited to a proprietary SCADA platform or specific devices and equipment. These are slot-based hardware PLCs that can communicate with field or substation devices and equipment via several network protocols. Allen-Bradley is also known as Rockwell Automation. The PLCs we use and recommend most often are GE RX3i controllers, Emerson Ovation controllers and Allen-Bradley ControlLogix controllers. What are some of the most commonly used and recommended PLC manufacturers and models for solar PV projects? The PLC can then run the embedded logic on its own without the need for an outside computer and operating system (OS) like Windows. The logic, or PLC program, is stored inside the hardware using non-volatile flash memory, a battery backed-up RAM, or a special chip. PLC programming is the process of programming or writing the logic that the controller will follow in order to control its connected devices. In this article we will focus on PLCs, which are a type of hardware-based PPC.Ī Programmable Logic Controller (PLC) is a dedicated piece of hardware that controls devices or processes based on pre-programmed, closed-loop logic. You can learn more about the difference between them here. There are two main types of PPCs: PC-based and hardware-based.