Nexto XF – #11 Series Contacts (AND Logic)

The objective of this tutorial is to demonstrate the insertion of serial contacts to assemble an AND logic in a MasterTool X project.

Components

Equipment: 1 computer/notebook.

Software: MasterTool X

Tutorial Sections

1. ARCHITECTURE
2. DEVELOPMENT

1. ARCHITECTURE

A computer/notebook will be required to use MasterTool X.

Figure 1. Computer running MasterTool X

2. DEVELOPMENT

In Ladder logic, AND logic is represented by connecting contacts in series. In this type of logic, the condition will only be true when all serial contacts are active.

Concept of AND logic

When two normally open contacts are in series:

• Both need to be TRUE
• Only then does logic power reach the coil
• If either is FALSE, the coil will not be activated

Inserting contacts into the network

With UserPrg open, select the logic line (Network) where the condition will be created.

The normally open contact can be inserted into the network in the following ways:

• Context menu:
  Right-click on the network and select Insert Contact.
• Top toolbar:
  With the network selected, click on the Insert Contact command.
• Toolbox (right side of the screen):
  Access the Ladder Elements tab and select and drag it to the Contact code line.
• Keyboard shortcut:
  With the network selected, press Ctrl + K.

Figure 2. Inserting open contacts to build AND logic

Assembling the AND logic

1. Insert the first normally open contact into the network.
2. Then, insert a second normally open contact to the right of the first, forming the series connection.
3. Associate a variable with each contact.
4. At the end of the network, insert a coil and associate the output variable.

This structure represents AND logic, where the coil will only be activated when all the conditions in series are met.

This type of logic is widely used for:

• Interlocks
• Safety conditions
• Conditional process releases

Figure 3. Building the AND logic
 

After assembling the logic with two contacts in series and the respective coil, it is necessary to download the application so that the program can be executed.

To do this, log in to the project and put the CPU in RUN mode. With the program running, the user can manipulate the variables associated with the contacts, either through Ladder logic or the variable table, changing their values ​​to verify the operation of the AND logic.

The coil will only be activated when all the variables of the contacts in series are in the TRUE state, confirming the expected behavior of the logic.

Figure 4. Operation of the AND Logic