A Quick Guide to Programs in Studio 5000 Logix Designer

Hey everyone, Ken Bourke here.

In today's post, I'm going to give you a quick introduction to programs in Studio 5000 Logix Designer. By the end of this post, you'll know what programs, local tags, and program parameters are. You'll also know how to schedule programs in a Studio 5000 Logix Designer project.

Let's start by talking about what programs are.

Programs

In Studio 5000 Logix Designer, a program is a container for application code and local data. You can use programs to divide large projects into smaller modules and modern Logix 5000 PLCs support up to 1000 programs per task.

Each program contains routines, local tags, and parameters.

We've already talked about routines in Studio 5000 Logix Designer so I won't cover them again. Instead, let's look at local tags and parameters.

Local Tags

Local tags are tags that are only accessible in the program where they are declared. The opposite of a local tag is a controller tag which is accessible globally in the project.

Local tags are very useful for encapsulating data that doesn't need to be available throughout the whole project.

You can monitor and edit local tags using a program's Parameters and Local Tags editor.

Parameters are a special type of local tag.

Program Parameters

Program parameters allow you to define an interface with a program. There are four types of parameters available in Studio 5000 Logix Designer: 

Input Parameters allow you to pass read-only data into a program

Output Parameters allow you to pass data write-only data from a program

InOut Parameters allow you to pass read-write data to and from a program

Public Parameters allow you to expose data in a program globally.

After defining a local tag as an Input, Output, or InOut parameter, you can use the tag's properties panel to connect a tag to the parameter.

Input parameters can be connected to exactly one tag whereas output parameters can be connected to multiple tags. A single parameter being connected to multiple tags is known as fanning.

Public parameters work slightly differently. Public parameters don't need to have a connection with a tag, instead they can be access from anywhere in the project using the notation shown here.

Parameters help to make programs more reusable by allowing exchange of data between programs.

Scheduling

Finally, programs in a task can be scheduled. You can view the program schedule for a task in the task's properties.

Programs are scanned in the order defined in the task's Program Schedule and Unscheduled programs are not executed.

Wrap Up

In this post, I gave you a quick introduction to programs in Studio 5000 Logix Designer.

Specifically, you learned what a program is, what a local tag is, what program parameters are, and what a Program Schedule is.

If you want to learn more about working with programs and using programs for modular programming in Studio 5000 Logix Designer, check out my course Modular Programming with Studio 5000 Logix Designer. If you sign up to a membership today, you get a 30-day free trial so you can follow that course and all of my other great courses for free.