Search for accessible devices and connect to your S7-1500 CPU. Expand the menu. Click on Reset to factory settings .

In the left-hand project tree, double-click . Select your network interface card and click Start search . Choose your S7-1500 CPU from the list and click Show .

Ensure you have the original, unencrypted TIA Portal project archive ( .ap13 through .ap19+ ) saved on a secure engineering workstation. Without this backup, you cannot reload the program to the PLC.

If you can still establish an online connection (e.g., if you have "Read access" but lost the "Write access" password), you can use TIA Portal to perform a factory reset.

Define your new protection levels and enter a strong password.

Power off the CPU. Insert the firmware card. Power on. The CPU will automatically enter firmware update mode (MAINT LED flashes). After 5-10 minutes, the update completes, and the CPU reboots with factory default settings – including a blank password .

Click the Download to device icon. TIA Portal will map the project, load the blocks, and establish the new access passwords defined in your offline project configuration.

Navigate to and remove or change the password. Copy the unlocked block into your active project. Without a Backup

The most common way to "reset" a forgotten access password is to wipe the existing configuration and start fresh. The S7-1500 stores its entire project, including security settings, on the . Steps to Clear the CPU Password: Power Down: Turn off the power supply to the PLC.

If you know the IP address of the PLC, can connect to it online, and the protection level allows for basic diagnostic communication without a password, you can initiate a reset via software. Open a blank project in .

However, you can reset the password by performing a factory reset, which clears the password protection along with the user program and configuration. ⚠️ Critical Warning Before You Begin