Getting Started with SIMATIC S7-1200 Programming: A Beginner’s Guide

The SIMATIC S7-1200 Programmable Logic Controller (PLC) by Siemens is an accessible, versatile option for industrial automation, offering features that allow users to automate tasks and control systems with ease. If you’re new to PLCs or just getting started with the SIMATIC S7-1200, this guide will take you through the essentials of programming, setting up your device, and using Siemens’ TIA Portal software.

Contents

1. Introduction to SIMATIC S7-1200

2. Getting Started with the TIA Portal Software

3. Basic Program Structure in SIMATIC S7-1200

4. Creating Your First Program

5. Testing and Debugging Your Program

6. Tips for Successful Programming with S7-1200

1. Introduction to SIMATIC S7-1200

The SIMATIC S7-1200 is designed for flexibility, ideal for small to medium automation projects. Equipped with both digital and analog I/O options, it supports a variety of configurations, communication protocols, and programming capabilities. The S7-1200 integrates seamlessly with Siemens’ TIA Portal software, which allows you to program, test, and optimize your PLC programs within a single interface.

2. Getting Started with the TIA Portal Software

To begin programming the S7-1200, you’ll need Siemens’ TIA Portal (Totally Integrated Automation Portal), which combines all Siemens automation tools into one user-friendly environment.

• Installation: Install TIA Portal software on your PC, and ensure you have the latest version compatible with the S7-1200.

• Connecting Your PLC: Connect the S7-1200 to your PC using an Ethernet or USB cable, and power up the PLC.

• Creating a New Project: Launch TIA Portal and start a new project. Select the S7-1200 as your device, input its model details, and configure its hardware settings.

• Setting IP Address: Assign an IP address to your PLC to allow communication between TIA Portal and your device. This step is crucial if you’re connecting multiple devices.

3. Basic Program Structure in SIMATIC S7-1200

The S7-1200 programs are structured using blocks and networks, with each serving a specific function:

• OB (Organization Blocks): These are the entry points for your program. For example, OB1 is the main program loop that runs cyclically.

• FB (Function Blocks): These reusable blocks contain specific functions or sets of instructions.

• FC (Functions): FCs are non-memory-retentive blocks useful for smaller, one-time functions.

• DB (Data Blocks): These blocks store data for specific functions or operations in the PLC.

Each of these blocks can contain networks, which are logical sections within the blocks, allowing for a more organized approach to programming.

4. Creating Your First Program

Now, let’s walk through creating a simple program in TIA Portal.

1. Define Your I/O Points: Start by defining the inputs and outputs of your S7-1200 in the hardware configuration. These could include sensors, switches, motors, or actuators.

2. Open OB1: This is the main block where most basic programs begin. Double-click on OB1 to open it in the editor.

3. Add Instructions: Using ladder logic (or an alternative programming language such as FBD or STL), start building your program:

• Example: To control a motor, create a simple rung that turns on an output when an input (e.g., a push button) is pressed.

4. Add Comments: Documenting each step helps you and others understand the program later.

5. Save and Compile: Save your program and run the compiler in TIA Portal to check for any syntax errors before uploading.

5. Testing and Debugging Your Program

Testing and debugging are essential steps to ensure your program functions correctly.

• Download the Program: Transfer the compiled program to your S7-1200 by selecting “Download to Device” in TIA Portal.

• Monitor Online: TIA Portal allows you to go online with the PLC to monitor its real-time status, helping you observe input and output states.

• Test Inputs and Outputs: Manually trigger inputs (e.g., press buttons or activate sensors) to verify that outputs respond as expected.

• Debugging: If the program doesn’t behave as expected, use breakpoints and watch tables to troubleshoot specific values or sections.

6. Tips for Successful Programming with S7-1200

• Start Simple: If you’re new to PLC programming, begin with simple logic and gradually add complexity.

• Use Meaningful Labels: Label your I/O points, blocks, and networks clearly to make the program easier to understand and modify later.

• Organize with Comments: Commenting your code is crucial, especially for complex logic. It aids in maintenance and helps others follow your work.

• Back Up Your Programs: Regularly save and back up your programs to prevent data loss, especially after major changes.

• Experiment with Simulations: TIA Portal includes simulation tools that allow you to test your program without needing a physical PLC, which is helpful for troubleshooting or testing changes.

Conclusion

Getting started with the SIMATIC S7-1200 and TIA Portal can seem complex, but by following this guide, you’ll build a solid foundation in programming basics and begin developing reliable automation programs. The S7-1200’s compatibility with TIA Portal provides a streamlined, flexible approach to managing your automation needs, from simple tasks to more advanced configurations.

As you continue, explore more features within TIA Portal and take advantage of Siemens’ documentation and tutorials to expand your skills. For further tips, tricks, and advanced topics, stay tuned to our blog for more in-depth articles on the SIMATIC S7-1200 series!