You can find most of the information in the articles on inputs and outputs in the products section on our KnowledgeBase.
Below you will find the answers to your questions:
What are the use cases of these relays? Is it dangerous to use these common relays with outputs having different power supplies?
- It depends on the specific circuit connection, but in most cases such a connection is undesirable.
Finally, is it recommended for safety reason to use a different power source between the unipi power supply and the dry contact equipment (in input) ?