iFrame Problem / https mixed content

[The Real Mr.T]

Hello,

I would like to integrate a ventilation system via iFrame in my Layout.
The problem is the page does not load.

   

If i try with local test.html it works as it should.
So i think there is no iFrame block from the Source.?.
   


So actually i`m not sure whats the Problem.
1.Http Source Ventilation System
2.SchneiderMachine/LogicMachine
3.Browser Secruity

Hopefully you can help me to find a good solution.
Greetings.