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.