Hello,
Apologies for the late reply.
Once a device reconnects to RMS, it sends information to RMS, and then the 5 minute interval starts. So for example, if the device connects to RMS at 14:06, information will be gathered at 14:06, 14:11, 14:16, and so on.
You can use the API to gather information on your devices, including the status of all your devices. For this purpose you can use the "GET /devices" endpoint with the "fields=status" parameter, this will list the statuses of all devices in your RMS company.
The status of devices does not get updated every 5 minutes, once the device disconnects, the status changes immediately and this shows in the web version of RMS as well as the API. This makes tracking the status of your devices via API possible as making an API call you would get the same result as you would if you were browsing the web version of RMS.