Siemens SIMATIC ET 200AL System Manual page 1221

Communications services
3.6 Secure Communication
Configuring secure HMI communication
1. Configure the HMI device with an alarm view.
Note
Without an alarm view you cannot identify the errors during connection establishment.
2. Configure the CPU with the required security settings. Select a PLC communication
certificate to protect the HMI connection or have the TIA Portal generate a PLC
communication certificate.
3. Configure the HMI connection between the CPU and the HMI device.
4. Download the project to the CPU and the HMI device. During the project transfer, the PLC
communication certificate and, if necessary, a CA (Certificate Authority) certificate is
transferred to the CPU and the HMI device.
Trusting the PLC communication certificate
During connection setup, the CPU transfers the PLC communication certificate to the HMI
device.
• When the PLC communication certificate is already available on the HMI device with the
"trustworthy" status, a secure HMI communication is automatically set up between the
CPU and the HMI device.
• When the PLC communication certificate is not available in the "trustworthy" status on the
HMI device, you will see a message in the alarm view of the HMI device informing you that
the CPU is not trusted along with an error code.
In this case, you must label the PLC communication certificate on the HMI device as
"trustworthy".
Depending on the type of your HMI device, follow these steps.
Basic Panels 2nd Generation
1. In the Start Center, select "Settings > Internet Settings > Certificate store".
2. In the "Available certificates in Device" list, select the PLC communication certificate of the
CPU.
3. Press "Trust".
4. Restart the HMI runtime software.
Unified Comfort Panels
1. Open the Control Panel.
2. Select "Security > Certificates".
3. In the "Certifcate store" selection list, select the entry "Other Certificates".
4. In the "Other certificates" list, select the PLC communication certificate of the CPU.
5. Press "Trust".
6. Restart the HMI runtime software.
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Function Manual, 05/2021, A5E03735815-AJ
Communication