Did you know that Mitsubishi FR-A800, FR-E800 and FR-F800 series Variable Frequency Drives (VFDs) include built-in Programmable Logic Controller (PLC) functionality?

That’s right, the VFDs/Inverters that you are used to using to drive your 3-phase motors have a built-in PLC that can be enabled to do logic control without an external device.  Not only this, but you can add extra input and outputs via add-on cards to expand the functionality.
Let’s look at a simple example – the E800 VFD 
 

This new inverter from Mitsubishi comes in two different styles, the classic serial connection and Ethernet connection. And both have a MELSEC 2K Step PLC included.  This might allow you to reduce internal components and save panel space, eliminating wiring time, and reducing system setup times.

Not only could you have a system comprised of a single VFD providing both functions of a PLC and Inverter, but you can use inverter-to-inverter communication.  The inverter-to-inverter link function enables communication between multiple inverters connected by Ethernet in a small-scale system by using the I/O devices and special registers of the PLC function.

You can also connect a GOT2000 series operator interface panel to the VFD to interact with the system and change various parameters in your PLC program.

Using expansion modules you can add more inputs and outputs to your inverter including not only digital inputs and outputs but analog as well. And it provides all the familiar programming languages that PLC programs are used to using, including Function Block Diagram, Ladder and on the E800 Structured Text.
 

All of this is done using Mitsubishi’s FR-Configurator 2 software and the FR Configurator 2 Developer programming environment.  

So the next time you have an application such as a conveyor application or pump application that requires more than just a motor drive you might consider the Mitsubishi family of inverters with built-in PLC.