You can add a single ICMP check. When it is active, a ping the host would be performed every 90 seconds.
You can add as many standard checks as needed. For each of them you must specify the service to be checked (like HTTPS), the port (like 80), and the check interval.
Note that the predefined TCP port checks will verify if a port is in listening state, and also if the answer is given by the protocol you expect. A custom TCP port check will only check for the port without inspecting the protocol. For example, a SSH check on port 80 will fail, since a Web server is answering on this port.