Micro820 – An A-B Ethernet PLC for $250?

MIcro820Ears perk up when I mention Rockwell released an Ethernet PLC with a list price of $249.

And surprisingly, there is a much interest in using it for home projects as there is for using it to automate small machines.

There’s no doubt about it, the “Micro820” PLC is, well small: It has just 20 points of I/O built-in (12 DI, 7 DO, 1AO.)

And for $249 you also don’t get the removable terminal blocks shown in the picture, or a USB port.

But with Ethernet built-in, USB is really not needed (but would be convenient to have.)

What you do get, besides Ethernet, is a serial communications terminal block supporting RS-232 or 485.

You also get a Micro SD card slot to store datalogs, recipes, or to use for program transfer.

You also get the ability to use four of the 24vdc digital inputs as 0-10vdc analog inputs, or 10K thermistor inputs.

And you get one dedicated 0-10vdc analog output, as well the ability to add two Micro800 plug in modules.

The unit programs like other Micro800’s using Rockwell’s free “CCW” software, which can be found HERE.

For more details about the Micro820, check out Rockwell’s product profile PDF which is available HERE.

I’d love to hear what personal project you might tackle if you had one at home?

If you have an idea for a “home automation” or “hobby project” you’d tackle with one of these units, please share it with us by clicking on the “post a comment or question” link below.

Until next time, Peace ✌️ 

Shawn M Tierney
Technology Enthusiast & Content Creator

Have a question? Join my community of automation professionals and take part in the discussion! You'll also find my PLC, HMI, and SCADA courses at TheAutomationSchool.com.

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  1. I’ve been day dreaming about doing an aquarium automation project for a while. I thought it would be fun. Control the lights and air. Monitor temps and filter pump flow. I’m sure I could think of a few more things if I actually had one.

  2. My experience with this micro820 is not good. I was loking for a PLC to make datalog in a MICROSD card but this device have problems doing that.
    At first I had tu upgrade the firmware from 6.012 to 8.011 to get the memory recognized at start up.
    Aftter that it worked fine logging some data, but after 8 hours of test, it stopped the logging, and now it can not even make backups of the program in the memory. It shows always the ErrorID 3:
    DLG_ERR_DATAFILE_ACCESS every time it tries to do a datalog. I have even formatted the memory twice, it is a Class 6 SDHC.

      • To elaborate on what Jeff said,

        You can get the software at AB.com, just search on “Connected Components Workbench.”

        While it is free and not related to RSLogix or Studio 5000, it does use (and comes with) RSLinx Classic Lite and Control Flash (also free)

        Hope this helps,

        Shawn Tierney

        Join my free community to follow along! You can also become a member and support our work at: Automation.Locals.com

  3. I experimented with a 850 at work with it linked to my mobile using Tesla Scada app. It works and is pretty cool. I just ordered one today to play with. I am using modbus tcp through wifi connection. I intended to use it to irrigate my garden with it hoop up to internet through mobile Scada.

    • Good morning William,

      Thanks for your feedback! Would love to see you screens as well as learn more about your app!


      Shawn Tierney


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