HTTPS overview

Unlike HTTP, HTTPS is a secure data transmission protocol. To ensure data security, the communication between the client and server is encrypted. To be able to use HTTPS, you need a certificate on your server that uniquely identifies the server or domain. This type of fee-based certificate is issued by an approved certification body and has a limited validity, e.g. 2 years. After this period has expired, you have to renew the certificate.

In a visual energy 4 project, the web server does not only communicate with the user via HTTP but also with the bus master. If you want to ensure fully encrypted HTTPS communication, you need to set up a certificate on the web server as well as on every bus master. 


Where and when is it advisable to use HTTPS?

If you are using visual energy in a scenario accessible via the Internet (cloud), at least the communication between the users and the visual energy 4 web should be encrypted, as otherwise, user names and passwords are transmitted as unencrypted plain text. If the program is only used in the company network, the effort used for certificate administration is, in most cases, not justified.

Can you use test certificates?

In many cases, test certificates you created yourself are sufficient to use encryption. However, they are not suitable for server or domain authorization. For this reason, test certificates are for internal use only.


Creatin a test certificate on the web server

To create a test certificate on the visual energy 4 web server, we recommend you follow the procedure described by Microsoft at


Setup with client-side test certificate

On the client side, enter https://... instead of http://... . Depending on the browser you use, a warning is issued. You can bypass this and add it to the exceptions in your browser. In the following section, setting up a client (test) certificate is described using the example of Google Chrome. Open the certificate information:


Save the certificate as a local file. A wizard guides you through the individual steps:



You can now add the saved certificate to your trusted certificates. The wizard will also help you with this task:


Close the browser and restart it. Make sure to close all browser windows. After restarting the browser, the client should now trust the server and display the HTTPS URL in green: