How to connect to a CompactLogix using Serial

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L23-Serial-FiIn today’s article I walk you step-by-step through how to configure RSLinx to communicate to a CompactLogix processor’s serial port using a serial cable and USB to Serial converter.

Part 1 – Reviewing needed cables, and finding PC comm port number

Step 1) A-B Cables, or low cost variant from Amazon

If you already have a bag full of Allen-Bradley cables, for this exercise you’ll need to grab the following two:


However, if you are on a budget, below are two low cost equivalents you can pickup on Amazon.com:

As an alternative to the above Null modem cable, you may find it more advantages to pickup the below standard serial cable and a Null Modem adaptor:

Step 2) Finding the com port for your USB to Serial device

Once you’ve installed the software for your USB to Serial converter, and plugged that cable in, you’ll need to find out what com port Windows has assigned to it.

To do this, first open device manager:

  • A quick way to get to Device Manager is to right click on “My Computer” and select “Properties”

My-Computer-Properties

  • You can also open Device Manager by launching the “System” applet from Windows Control Panel.

Control-Panel-System

Once Device Manager is open, scroll down and expand “Ports” and you should see your device listed as one of the available ports

Device-Manager-Ports

Part 2 – Configuring RSLinx Classic

Step 1) Launch RSLinx Classic and open “Configure Drivers”

You can open the “Configure Drivers” configuration menu by either clicking on the “Cable” icon on the RSLinx toolbar as shown below, or by choosing it from the “Communications” menu.

RSLinx-Configure-Comms

Step 2) Select the “RS-232 DF1 devices” driver

RSLinx-RS-232-DF1-Devices

Step 3) Click on “Add New,” and then click on “OK”

RSLinx-add-new-driver

Step 4) Select the “Comm Port” which is connected to your CompactLogix

RSLinx-DF1-Devices-Select-Com-Port

Step 5) Click on “Auto-Configure”

RSLinx-DF1-Devices-Select-Auto-Config

Step 6) After a few moments if all your cables are connected correctly you should see the below message:

RSLinx-DF1-Devices-Select-Auto-Config-Sucess

Step 7) Now click on “OK,” and then expand the “AB_DF1-1” network in the “RSWho” window. Here after a few seconds you should now your CompactLogix:

RSLinx-Browse-RSWho

NOTE: Watch me run through the above steps in today’s episode of The Automation Minute!

I hope the above article on how to setup RSLinx to communicate to a CompactLogix was helpful.

If you have any questions or comments, please feel free to share them with us by filling in the “Leave a reply” form at the bottom of this page.

Sincerely,

Shawn Tierney
Automation Consultant
Insights In Automation

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The Automation School – PAC Basics – Article Banner Top
Comments
  1. In today's article I walk you step-by-step through how to configure RSLinx to communicate to a CompactLogix processor's serial port using a serial cable and USB to Serial converter.

    Part 1 - Reviewing needed cables, and finding PC comm port number

    Step 1) A-B Cables, or low cost variant from Amazon

    If you already...

    Click here to view the full article.

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