how to use the jump to subroutine jsr

[rwachter0001]

does anyone know how to use the jump to subroutine jsr function

 

[Phrog30]

Yes, I do.

 

[jvdcande]

Me too, but not in all brands/models.

 

[shooter]

normally a subroutine is called and at the end of this subroutine there is a return. in State machines a jump is better.
if condition is true do JSR

 

[TConnolly]

Since your previous post was about a ML1500 I'm going to assume you are referring to the JSR instruction in Logix500.

If you'll look at the project tree on the left hand side of your screen in Logix500 you'll see something called program files. In a micrologix ladder 2 is the main ladder file. (This is only the case for Logix500 PLCs. PLC/5s and ControlLogix are different). Below ladder 2 you can have as many ladder files as you want up to the limits of memory, but the only way to call them is from the main program with a JSR, or with an interrupt (an advanced topic that we'll leave for you to explore as you get more experience). You add a new ladder file by right clicking on program files and selecting new.

Dividing your logic into smaller ladders helps you organize our program to make writing it easier as well as make future troubleshooting easier. For example, you might put all of your analog scaling in one subroutine and all of your outputs in another with product quality tracking in yet another. Then in your main program #2 you place a JSR instruction to call each of these other ladders in the sequence you want them executed. It is a common practice for programmers to place everything is subroutines and ladder two consists on nothing by a few rungs each with just one JSR instruction on it.

 

[gbradley]

This is what it looks like in RSLogix 500
I don't remember what the U stands for, but the file number corresponds to the file where you have your subroutine logic located.