Nexto XF #71 – Creating Data Structures

This tutorial will show how to create and use a data structure in MasterTool X

Components

Equipment: 1 computer/laptop.

                            1 XF300/315/325/325-W

Software:  MasterTool X

Tutorial Sections

1. ARCHITECTURE
2. DEVELOPMENT

1.ARCHITECTURE

A computer/laptop is required to use MasterTool X.

Figure 1. Computer running MasterTool X

2.DEVELOPMENT

The use of data structures (STRUCT) is very common in automation when you want to organize variables related to the same equipment or process, facilitating reading, reuse, and maintenance of the code.

Creating a STRUCT (DUT)

To create a structure in MasterTool IEC XE:

1. Right-click on Application
2. Select Add Object
3. Choose the option DUT (Data Unit Type)
4. Define a name for the structure

   • Example: motor

      

     
     

Figure 2. Creating a Struct – Data Structure

Declaring the structure

Within the DUT, declare the variables that are part of the structure:

TYPE motor :

STRUCT

    start: BOOL;

    status : BOOL;

    current : INT;

    temperature : REAL;

END_STRUCT

END_TYPE

Concept

The STRUCT allows grouping several variables within a single type, representing a logical object, such as a motor.

In this case, all the motor's information is organized in a single block:

• Start command
• Status
• Current

• Temperature

   

Figure 3. Declaration of the structure's internal variables

Instantiating the structure

After creating the STRUCT, it needs to be instantiated in the program.

In user.prg, declare:

motor1 : motor;

motor2 : motor;

Using it in logic

To access the elements of the structure, use the following syntax:

instance_name.variable_name

Examples:

• motor1.start
• motor1.status
• motor2.current

Practical example

In Ladder logic:

• A normally open contact:
  motor1.start
• Activating a coil:
  motor1.status

The same can be done for another motor:

• motor2.start→ motor2.status
  

Figure 4. Using the Struct in logic

How it works

Each instance of the structure works independently:

• motor1 has its own values
• motor2 has its own values

Even though they are of the same type (motor), they do not interfere with each other.

Applications in automation

The use of STRUCT is ideal for:

• Representing equipment (motors, valves, sensors)
• Organizing related variables
• Creating cleaner and standardized code
• Facilitating system maintenance and expansion
• Reusing structures in different parts of the project

Important notes

• The STRUCT is created as a DUT
• It needs to be instantiated for use
• Each instance is independent

• Significantly improves project organization

   

Figure 5. Structure operation in logic