Book Image

Instant PLC Programming with RSLogix 5000

Book Image

Instant PLC Programming with RSLogix 5000

Overview of this book

RSLogix5000 is a user friendly IEC61131-3-compliant interface for programming the current generation of Rockwell Automation PLCs, which includes Ladder Diagrams (LD), Graphical Function Block Diagrams (FBD), Graphical Structured Text (ST), and Sequential Function Charts (SFC). Instant PLC Programming with RSLogix 5000 captures the core elements of PLC programming with RSLogix 5000 with a minimal investment of time. We will avoid getting into control theory and focus on condensing the information specific to RSLogix 5000. We have selected the key areas of RSLogix and provide a step-by-step approach to teaching them. This book start by follows the steps involved in creating a new RSLogix 5000 project and configuring racks, slots, and channels. Next, we will create routines using the various languages available in RSLogix 5000, troubleshooting and resolving issues we encounter along the way. Finally, we will dive into the advanced features, such as online changes, code generation, task management, and user-defined structures. You will also learn object-oriented PLC programming techniques using advanced features like user-defined types (UDTs) that improve the maintainability, uniformity, and readability of our routines. We also highlight the strengths and limitations of online changes and demonstrate techniques to maximize flexibility. You will learn everything you need to get up and running with RSLogix 5000 as well as best practices used by industry experts.
Table of Contents (7 chapters)

Downloading explained (Simple)

In this recipe, we will demonstrate how to download your application to a PLC in a step-by-step process.

Getting ready

To complete this recipe, you will need a PLC or RSLogix Emulate 5000 running.

How to do it...

  1. Before we can communicate with our PLC, we will need to set up the communications path in a separate program called RSLinx that is installed with RSLogix 5000. Open RSLinx and then, from the drop-down menu, navigate to Communications | Configure Drivers as shown in the following screenshot:

  2. The Configure Drivers window allows you to add Driver to the Configured Drivers list. In the Available Driver Types group box, use the dropdown and select the EtherNet/IP Driver option, and then click on the Add New… button.

  3. Next, a window will appear asking you to specify the name of Driver; use the default driver name and click on OK.

  4. A Configure Driver window will appear next; simply click on OK to accept the default settings.

  5. We have completed our communications driver configuration in RSLinx, so we can close that application for now and switch back to RSLogix 5000.

  6. In order to download our program to the controller, we first need to specify the communications path. You can see the currently selected communications Path on Communications Toolbar:

  7. Click on the Who Active icon to the right-hand side of Communications Toolbar and specify the communications path. This icon looks like the following screenshot:

  8. The Who Active window will appear and allow you to specify the path to your PLC. Expand the AB_ETHIP driver we added using RSLinx, select your PLC, and then click on the Download button.

  9. A version mismatch message may appear; just click on OK to accept and overwrite the current PLC program.

  10. Now that we have downloaded the PLC program to the PLC, if you check the PLC status pane in the top-left corner of Logix 5000, you will see that you are now online.



Downloading a program to a PLC can be dangerous on a running plant. Downloading a new program or a new version of a program will stop a process that is running. Also, it is hard to be sure what code and values you are loading onto the PLC, so, when the process starts up again, things may go a bit haywire. If the plant simply cannot go down, you can make changes online (which we will explore in more detail later in the book).