btalawyer.blogg.se

You will notice that every data structure is specified by a letter, an integer as well as string.

RSLogix 500 - data structures in the IO tree under the section called "Data Files" Note that this is different from RSLogix 5000.

In an RSLogix 500 application, the user will find currently specified data structures in the IO tree under the section called "Data Files" (See below). We will revisit their creation and use here. However, they’re created and used in a different manner in RSLogix 500. We’ve introduced data structures in RSLogix and Studio 5000 in a separate tutorial ( RSLogix 500 Data Structures). Before we get into cross-referencing however, we will take a deep dive into the different data structures we have available in RSLogix 500, explain how they are specified and discuss the basics of data in RSLogix 500 based PLCs. In this tutorial, we’re going to look at the “cross-referencing” function of RSLogix 500 (Similar to RSLogix 5000), go over the steps on how to use it and cover how it can help you trace existing code faster and understand what’s going on in the PLC. The specification of each tag may be confusing to a beginner and unclear when it’s used as word, bit or byte in different instructions. The second challenge many PLC programmers come across as they get started in RSLogix 500 lies in the data structures. Therefore, it’s easy to become frustrated trying to figure out where a certain tag is being used, how it ties into the logic and why it’s being used in certain places. This task creates a challenge for novice PLC programmers as the interface in RSLogix 500 as well as RSLogix 5000 is unlike any other. In fact, most PLC programming jobs will require you to work with existing code rather than write it from scratch. Many of those who start with PLC programming are faced with the challenge of deciphering code written by someone else. Cross Reference and Data Structures Introduction