Setup the Micrologix 1400 PLC for Modbus RS485 Communication

Name: Setup the Micrologix 1400 PLC for Modbus RS485 Communication
Rating: 4.6 (110 reviews)

Learn how to configure the Allen-Bradley Micrologix 1400 PLC for Modbus RS485 Communications in Master and Slave modes

Created byEmile Ackbarali

Last updated 5/2026

English

What you'll learn

Become familiar with the Micrologix 1400 PLC
Become familiar with the RSLogix Programming Environment
Learn how to use the RSlinx Classic OPC Server
Learn how to configure port communications on the Micrologix 1400 PLC
Learn how to configure Modbus communication on the Micrologix 1400 in Master and Slave modes
Understand the process for determining the required setup for the Micrologix 1400 PLC
Establish Modbus RS485 communication with a RS485 Modbus slave device when in Master mode
Connect to a Modbus master when in slave mode

Course content

6 sections • 17 lectures • 1h 21m total length

Introduction3:39
Learn to configure the Micrologix 1400 for Modbus RS485 communication, set as master and slave, and test with a temperature and humidity sensor.
Accessing Attached Resources and Setting Optimal Video Resolution2:23

Configuration as a Modbus Master Device - The High Level Plan2:27
The ML1400 will be configured as a Modbus master device specifically to communicate with the Datanab Temp/Humidity sensor and read in the values of Temp/Humidity.
Standard Approach for Connecting Devices for Modbus Communication4:21
A series of questions are outlined. Once these questions are answered, all the information that is required for the Modbus comms will be obtained.

Physical Connections on the Datanab Temp/Humidity Sensor5:23
The user manual for the Datanab device is perused to find physical connection information.
Modbus Configuration of the Datanab Temp/Humidity Sensor4:24
The Modbus configuration of the device is actually done through Modbus communication. Initial Modbus communication is done with default parameters.
Configuration of the Modbus Slave using Modscan326:21
Modscan32 is used to change the Device ID from the default of 254 to 10.

Physical Connection of the Micrologix 1400 as Modbus Master8:12
An RS485 connection is made between the Micrologix 1400 and the Modbus Slave.
Connecting to the Micrologix 1400 for Modbus Configuration3:48
A network connection over the LAN is made to the Micrologix 1400 PLC.
Setting up RSLinx and RsLogix for Micrologix 1400 Modbus Configuration8:07
RSLinx and RSLogix are run and set up. Initial communication with the PLC is established.
Understanding the Memory Map of the Micrologix 1400 PLC5:12
The memory map of the Micrologix 1400 PLC is divided up into data files. The lecture looks at the various data files as they appear in RSlogix 500.
Writing the PLC Ladder Logic to Implement Modbus Master Communication - Part 16:29
Writing the PLC Ladder Logic to Implement Modbus Master Communication - Part 1
Writing the PLC Ladder Logic to Implement Modbus Master Communication - Part 26:06
Writing the PLC Ladder Logic to Implement Modbus Master Communication - Part 2
Running the Ladder Logic / Testing the Master - Slave Modbus RS485 Communication2:28
The Micrologix 1400 is placed into Run mode and the values in the memory of the PLC compared with the displayed values on the temp / humidity sensor.

Configuration of the Micrologix 1400 as Modbus Slave - The Plan2:17
A diagram overview of the setup that will be used to configure and test the Modbus slave communication is given.
Using RSLogix 500 and Modscan32 to Configure and Test Modbus Slave Communication8:24
RsLogix 500 is used to change the configuration of the Micrologix 1400 PLC to Modbus Slave. Modscan32 is then used as the Modbus master application that reads data from and writes data to the Micrologix 1400 acting as a Modbus slave.

Requirements

Basic working knowledge of the Modbus RTU protocol.
Familiarity with the installation of software applications on the Windows OS platform
Elementary understanding of the Ladder Logic programming language
Basic understanding of elementary electronics

Description

Upon seeing the title of this course, you may think that it is overly specific. After all, the Modbus protocol is by far the most popular open communications protocol in the automation industry, and hundreds of devices from different manufacturers are Modbus compliant.

So why concentrate on just one specific PLC? Well, it's based on almost 2 years of feedback from persons enrolled in my courses. It turns out that the Allen-Bradley Micrologix Series of PLCs is insanely popular, especially the 1400. I have received so very many questions asking advice on the configuration of Modbus on this device, that I finally decided to make a course on the subject.

The course is short, gets to the point quickly and is ultra-practical. In it, I give you what you need to know to perform a very specific task, the configuration of Modbus on the PLC in both Modbus master and slave modes.

In each mode, after performing the configuration, I demonstrate the communication by creating a very simple 2-device network. So this course will imitate real-world conditions as closely as possible. We will be configuring and testing. That's what happens in the real world, that's what you would do in your job.

So invite you to jump in and let's learn how to do!!!

Who this course is for:

Electrical Engineers
Electrical Technicians
Electrical Tech or Engineering Students
Process Control Technicians and Engineers
Process Automation Engineers
Programmers working in the Process Automation field

Setup the Micrologix 1400 PLC for Modbus RS485 Communication

What you'll learn

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Course content

Introduction2 lectures • 6min

Configuration as Modbus Master - The Plan2 lectures • 7min

Physical Connection and Configuration of the Modbus Slave3 lectures • 16min

Physical Connection and Configuration of the Micrologix 1400 as Modbus Master7 lectures • 40min

Configuration of the Micrologix 1400 as Modbus Slave2 lectures • 11min

Bonus Section - How to Always get the Lowest Prices for my Courses1 lecture • 2min

Requirements

Description

Who this course is for: