README.md

About the "StartProcessFromService" sample

The "StartProcessFromService" sample server extension is a server extension that starts a process as a specified user, even when the current process runs as a service under the SYSTEM account. This is useful when server extensions loaded into a TwinCAT HMI server running as a service need to start a user process. To start a process from a service this sample uses the CreateProcessAsUserA function.

First steps:

• Working with server extensions

Example requests

Start Notepad in a new window from a server extension loaded into a TwinCAT HMI server running as a service:

{
    "requestType": "ReadWrite",
    "commands": [
        {
            "symbol": "StartProcessFromService.StartProcess",
            "commandOptions": [ "SendErrorMessage" ],
            "writeValue": {
                "applicationName": "C:\\Windows\\System32\\notepad.exe",
                "showWindow": true
            }
        }
    ]
}