How to Connect to Micrologix PLC

By Aalhad Deshmukh

Updated September 15, 2017

Items you will need

  • RSLinx Classic Lite software

  • RSLogix software

Miicrologix PLCs are manufactured and sold by Allen Bradley. PLCs are programmed using ladder logic. In order to program PLCs, it first important to establish connectivity between a computer and the PLC. A computer can connect to a Micrologix PLC using special software called RSlinx and RSLogix, which are provided by Rockwell Automation. These software communicate with the Micrologix PLC using a RS232 Serial cable.

Using RSLinx Classic Lite to Install Serial Communication Drivers

Connect the computer to the PLC using a serial communication cable. Power up the PLC.

Launch the RSlinx Software on your computer. In the "Tool" bar menu, click on "Configure drivers" button. A window with the title "Configure Driver" opens.

Click on the "Available Driver Types" drop-down list button and choose "RS232 DF1" from the displayed list. Another button called "Add" will become enabled on the "Configure Driver" window.

Click on "Add" to open the window for configuring the RS232 driver. Choose the default values for the "COM Port," "Baud," "Partiy," "Stop Bits" and "Protocol" sections. Click on "Close" to accept these settings and close the configuration window for the RS232 driver.

Click on "RSWho" button on the "Tool" bar menu. This will open an expandable list that displays all the active communication drivers. The driver "RS232 DF1" will be displayed in this list.

Double-click on the driver to expand a sub-list that displays all the PLCs that are connected to the computer. The PLC that is connected using the serial communications cable to the computer is automatically listed.

Using RSLogix Software to Communicate with the PLC

Launch the RSLogix software while the RSLinx Classic Lite software is still running. Click on "File, New Controller" and choose from the displayed drop-down list the model of the Allen Bradley Micrologix PLC that you want to connect to.

In the "Project" section, click on "Communications, Who active." This option is similar to the "RSWho" button in the RSLinx Classic Lite software. An expandable list showing the "RS232 DF1" driver and the PLCs connected to the computer will be displayed.

Click the "RS232 DF1" driver and then click on "Set project path." This will save the information of the serial driver and the path to the PLC in the RSLogix software.