RSLogix 500 Data Types and Cross Referencing

Many of those who start with PLC programming are faced with the challenge of deciphering code written by someone else. In fact, most PLC programming jobs will require you to work with existing code rather than write it from scratch. This task creates a challenge for novice PLC programmers as the interface in RSLogix 500 as well as RSLogix 5000 is unlike any other. 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 is a companion discussion topic for the original entry at

first thanks and i am happy to join to this site
second i have some question about allen bradly plcs??
what about double integer in rslogix 500??
the question with another way — is micrologix 1100 has double integer data file ??
and how to convert integer to float and how to convert float to integer??

No, RSLogix 500 based PLCs don’t have a double integer structure due to how the PLC architecture was done at the time.

You can use a MOV instruction to convert, but as you would imagine, some of the data is always lost.

Hello everyone. I hope you all are doing good. I am writing to ask a question about recipe. I have been migrating projects from RS500 to Studio5000 but I am stack on recipes creation in Studio 5000. I want these recipes to do the same as they do in RS500. Any answer or idea about this topic will be appreciated. Also, are there some ways we can go around recipes in Studio 5000

Thanks for sharing.
I want to know about the importance and usage of the R6: Control data file, what is its usage, and how to use it?

Hi Muhammad,

Control structures are required for special instructions. In RSLogix 500 some examples include PID, FLL, etc. These instructions use control structures for certain variables. They’re required to use those instructions in your programs.

I hope that makes sense.