How to Reset Siemens PLC: Step-by-Step Guide for All Models (S7-200, S7-300, S7-400, S7-1200, S7-1500)

Resetting a Siemens PLC can solve a wide range of problems – from communication errors and forgotten passwords to restoring factory settings for a new configuration. Whether you’re using a Siemens S7-200, S7-300, S7-400, S7-1200, or S7-1500 PLC, this guide will walk you through how to reset your Siemens PLC safely and effectively using Siemens TIA Portal, Step7, or MicroWIN software.

If you’ve ever wondered how to bring your Siemens PLC back to default settings or fix an unresponsive CPU, keep reading – this complete guide covers it all.

Why You Might Need to Reset Your Siemens PLC

There are several reasons why resetting a Siemens PLC becomes necessary:

• Forgotten password or locked PLC
  
• Corrupted or incompatible program file
  
• Switching to a new project or production line
  
• Communication errors or lost connectivity
  
• Clearing memory before uploading a new program
  

No matter your situation, understanding the correct reset method for your PLC model is crucial – a wrong reset could delete essential data or disrupt communication.

If you’re locked out of your Siemens PLC due to a password issue, you can check out our dedicated software tools like
Sim EKB Install for Siemens Software Free Download
and
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Types of Siemens PLC Resets

Before we jump into the step-by-step guide, it’s important to understand that Siemens PLCs can be reset in a few different ways depending on your needs:

1. Warm Restart (Soft Reset)
   
   • Used to restart the PLC without clearing user data.
     
   • Keeps your current program and configuration.
     
   • Ideal for quick troubleshooting.
     
2. Cold Restart (Full Memory Reset)
   
   • Clears the PLC memory and reinitializes hardware.
     
   • Often used when loading a completely new program.
     
3. Factory Reset (Memory Reset + System Clear)
   
   • Restores the PLC to its original factory state.
     
   • Deletes all user programs, data blocks, and configurations.
     
   • Recommended when transferring PLC ownership or fixing deep system errors.
     

Tools and Software Required

To perform a reset, you’ll need the correct Siemens software depending on your PLC model:

• S7-200 PLC → Use Step7 MicroWIN V4.0 “S7-200” Siemens PLC Software
  
• S7-1200 / S7-1500 PLC → Use TIA Portal V17 Full Version Free Download
  
• S7-300 / S7-400 PLC → Use Step7 V5.6 Siemens PLC Software Free Download
  
• HMI Panels (if connected) → Use Simatic HMI ProTool Pro 6.0 SP3 Siemens HMI Software
  

Having the right software version ensures smooth communication between your computer and the PLC via PG/PC interface, Ethernet, or MPI/Profibus.

Step-by-Step: How to Reset Siemens PLC (All Models)

Step 1: Connect Your PLC to PC

Use a programming cable (USB, MPI, or Ethernet) and open your Siemens software (TIA Portal or Step7).

• Go to Accessible Devices and select your PLC.
  
• Check the connection and ensure the CPU appears online.
  

If you have trouble connecting, use tools like
Automation License Manager V6.0 SP12 Free Download.

Step 2: Switch the CPU to STOP Mode

In the project tree:

1. Right-click the CPU.
   
2. Select Operating Mode → STOP.
   
3. Wait for the CPU status to change to STOP in the diagnostic window.
   

This ensures that no active processes are running during the reset.

Step 3: Perform the Reset Command

Depending on your model:

For S7-200 (MicroWIN):

1. Go to PLC → Clear/Reset Memory.
   
2. Select Clear Program and Data Memory.
   
3. Confirm when prompted.
   

S7-300 / S7-400 (Step7):

1. Open SIMATIC Manager → Select the PLC.
   
2. Click PLC → Clear → Reset to Factory Settings.
   
3. A message will appear confirming that the PLC will erase all data.
   

For S7-1200 / S7-1500 (TIA Portal):

1. In Online Mode, right-click your PLC.
   
2. Select Online & Diagnostics → Functions → Reset to Factory Settings.
   
3. Choose Reset all (including IP and memory).
   
4. Confirm and wait for completion.
   

Step 4: Reboot and Reload Program

After the reset:

• Power cycle the PLC or restart it from your software.
  
• If you want to load a new program, open your project and select Download to Device.
  

If your PLC was password-protected and you’ve successfully reset it, you can now upload new logic using
Step7 MicroWIN SMART V2.5 for PLC S7-200 Siemens.

Pro Tips Before Resetting

• Always back up your program before performing a reset.
  
• Use the PLC’s hardware switch only as a last resort – software reset is safer.
  
• Ensure your PG/PC interface is configured correctly in the “Set PG/PC Interface” menu.
  
• For networked PLCs, document IP addresses to avoid connection loss after reset.
  
• If your system includes an HMI or SCADA, disconnect them before resetting the PLC.
  

You can learn more about connecting and configuring HMI software with PLCs here:
Download WinCC Flexible 2008 SP5 Version

Troubleshooting Common Reset Problems

1. PLC Not Responding After Reset

Check your communication settings or cable type. Some PLCs need a firmware reload using TIA Portal V13–V17.

2. Factory Reset Option Greyed Out

Make sure you are in Online Mode and the PLC is in STOP.

3. PLC Password Required

If you’re still locked, use
Sim EKB Install 2024 for TIA Portal V17
to handle licensing issues or check our unlock software section for models like Omron, Mitsubishi, or Delta PLCs.

Related Software and Tools for Siemens PLC Users

To make your automation work easier, here are some essential Siemens tools available on our site:

• Download Siemens Automation License Manager V6.0 SP8 Free
  
• Download Simatic Step7 Pro 2010 SR2 Free
  
• Download TIA Portal V14 SP1 Full Package
  
• Download S7 PLCSIM Advanced V6.0 Free
  

These tools are widely used by automation engineers to program, simulate, and maintain Siemens PLC systems.

Explore Other Brand PLC & HMI Software

At PLCUnlock.com, we don’t just provide Siemens tools – we support all major industrial brands. Explore:

• Mitsubishi PLC Software & License
  
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• Panasonic PLC Programming Tools
  
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Final Thoughts

Resetting a Siemens PLC isn’t just about clearing memory – it’s about restoring control and ensuring stability in your automation system. With the right Siemens software and a proper understanding of reset procedures, you can quickly recover from programming issues, password locks, or configuration errors.

Whether you’re working with an S7-200 on a small machine or an S7-1500 in a large automation line, following this guide will help you safely perform the reset and get back to production fast.

And if you ever need unlock software, HMI tools, or PLC programming suites for Siemens or any other major brand, you can always find verified and updated versions at
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