Configure Trusted Server Certificates - References - SIMATIC AX - AX Hardware Engineering documentation - Hardware Engineering,

For transport protocols TLSOnlyServerAuthentication and TLSServerAndClientAuthentication, trusted servers have to be added. Server certificates are used to verify that the PLC will only connect to trusted system logging servers. Public keys (*.cer) for multiple servers can be configured in parameter TrustedServerCertificates. The path to the files can be given as an absolute path or relative to the *.hwl.json file of the module. When setting AutoAcceptServer to true all Syslog servers will be automatically accepted in runtime and no certificate validation will be performed.

{
  "Type": "Syslog",
  "Enabled": true,
  "Parameters": {
    "TransportProtocolType": "TLSServerAndClientAuthentication",
    "Address": "192.168.0.153",
    "Port": 500,
    "TrustedServerCertificates": [ "SysLogServer1.cer", "C:/Certificates/SysLogServer2.cer" ]
  }
}