CompactLogix L3I’ve been teaching Logix and View introductory classes the last few days, and have to say I’ve been a little surprised how many people are not familiar with Rockwell’s current generation of CompactLogix.

With that in mind, in today’s article I’ll cover the seven things you need to know about this line of small Logix processors:

NOTE: To find out seven more things you should know about the current generation of CompactLogix, check out our additional article HERE.

Seven things you need to know about the current generation of CompactLogix

1) Now referred to as the 5370 family of CompactLogix processors

While the ControlLogix has had a 5000 designation from the very beginning, this latest batch of CompactLogix processors is the first to receive this number.

So while the current generation of ControlLogix processors, the 1756-L7x, are referred to as 5570, the current generation of CompactLogix controllers are referred to as 5370.

2) Only supported in version 20 and up

If you plan on using the current generation of CompactLogix, you’ll need to choose a RSLogix 5000 / Studio 5000 version of 20 or higher.

3) USB port replaces DB9 Serial Port

Gone is the old DB9 serial port, replaced with a standard USB port that current versions of RSLinx find and configure automatically.

This virtually eliminates the need to configure RSLinx, and BOOT-P is no longer needed as you can set the Ethernet’s port address by browsing to it through the USB port.

4) No more battery, replaced with capacitor

Gone is the expensive battery use for memory retention, as it has been replaced with a capacitor.

Now when the processor is powered off, the capacitor powers the transfer of the program from high-speed volatile memory to internal non-volatile memory

5) SD Card used for non-volatile memory, 1gb included in box

Gone also are the days when you had to order removable non-volatile memory separately.

Today’s CompactLogix comes with a 1gb industrial SD card for use as non-volatile memory, and with room to spare for all your project files.

6) Additional memory for new features

While we haven’t seen much done with this yet, since version 21 it has been used to store all your offline documentation on board the controller.

Future plans for this memory include a Controller based datalogging. However, no word lately on what version will include it (my guess is v26.)

7) Multi-core on the inside

Features of the future, like the previously mentioned controller based datalogging, may require more processing power than a single core can provide.

So by including a multi-core processor in the current generation of CompactLogix controllers Rockwell has paved the way for some pretty interesting options in the future.

I hope this article about the 5370 CompactLogix was helpful!

If you have any questions, suggestions, comments, or corrections please don’t hesitate to leave them with us by using the “post a comment or question” link below,

Until next time, Peace ✌️ 

Shawn M Tierney
Technology Enthusiast & Content Creator

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  1. From our supplier, the L30ER is less expensive than the L32E. The catch is that there is no built in ASCII messaging for serial printing. A 1769-ASCII or 1734-ASCII would need to be added. However, TCP/IP printing is available because of the built in EWEB properties. This allows direct printing to network printers without the need to convert serial to Ethernet. The information is on the Rockwell website as topic 33240 – Logix platform: Open Sockets with Ethernet Printers. The samples are helpful.

    When a full page is sent to a network printer, I have found that it is better to slow the output down to the printer to 100ms per line. This completely eliminated an issue with a partial print of a line that happened once in a while.

    If rack space is a concern and a serial printer is still used, the TCP/IP output can be converted using a device server such as the SENA LS100. It is easy to setup and reliable.

    Another possible use of the TCP/IP messaging is that historian real time turn point information can be sent and captured in the form of a CSV file.

    • Dadadadeo,

      Thank you very much for the information on Ethernet printing! I’ve yet to use that feature but do love the open sockets support, and have given the Modbus TCP AOI a test drive and it seems to work well.

      Thanks again,

      Shawn Tierney

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


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