New Mitsubishi Electric Compact PLC: More I/O Power in a Smaller Size

Mitsubishi FX5S Compact PLC

Just about every PLC manufacturer has a line of compact or even ‘micro’ form factor PLCs to allow integration in all sorts of applications. These controllers typically have some onboard inputs and outputs, some are even PWM/pulse train outputs, and analog inputs/outputs. A compact PLC also has a very small form factor, and most modern models will generally have a variety of configurable industrial field bus capabilities. These PLCs are great for small projects that only require a few I/O points and a small amount of motion. Mitsubishi Electric has recently added to their iQ-F series of compact PLCs with a low-cost version called the FX5S.

The new FX5S from Mitsubishi Electric Factory Automation. Image used courtesy of Mitsubishi Electric

The MELSEC FX5S Compact PLC

Compact and micro PLCs are becoming very popular, especially with the IIoT crowd. The FX5S is geared toward IIoT applications where communication and cost are bigger factors than available I/O count. The specifications of the FX5S are what you would expect from a micro or compact PLC. The FX5S can support up to 60 I/O with onboard and integrated ethernet over CC-Link IE industrial protocol. For the user interface, the FX5S has its own internal web server that can service custom webpages, or the CC-Link IE protocol can be used to connect to an HMI. The processor is capable of scanning logic at 84 nanoseconds with up to 48 thousand steps, and includes the capability of controlling up to four servo controllers or VFD axes.

The controller uses the same GX Works3 software that the larger versions use, so there is no need to download or learn new software if you choose this PLC for your project. The FX5S comes in three model lines, all of which use 120 VAC as the supply voltage, so no need for special power supplies. There are versions for 16 in/14 out, 24 in/16 out, and 36 in/24 out, all with the outputs being either relay or transistor (DC).

Optional front-mounted modules include an SD card holder (shown) as well as communication channels. Image used courtesy of Mitsubishi Electric

Expansion modules can be purchased for serial communication and SD memory cards. Additional I/O modules can be added to the side of the controller allowing for analog inputs or outputs, RTD or thermocouple temperature probes, and analog multi-modules.

FX5S Applications

Smaller form-factor PLCs, such as Mitsubishi’s new FX5S, are great for small projects where the I/O count is not as important. Examples would be industrial ovens, small breweries, and press shops. Where compact PLCs really show their strength is within brown-field applications where the customer wants to collect data for a modern IIoT application on older equipment. Instead of replacing working equipment, why not add a few sensors and an economical PLC to consolidate those sensors’ signals and communicate to an industrial edge server?

Micro PLCs, although small, are highly capable and can be used to collect data or control fairly complex processes. Image used courtesy of Adobe Stock

Data collection 20 years ago was expensive and not always required, but today, data collection is more affordable and companies are starting to realize the benefits (arguably, the necessity) of collecting data on equipment. By adding a few part counter sensors and maybe a faulted sensor, or condition monitoring devices, you can determine a lot about your equipment. With the FX5S having a CC-Link connection, it can communicate to larger PLCs allowing you to isolate your database communication logic from the rest of the assembly line, essentially creating an add-on to existing or future assembly projects without disturbing the integration team.