How can I see which devices are connected right now?

Open a client, then Authentications → Sessions. It lists what's connected to that client's network right now: the device, its IP address, which network or switch port it's on, how long it's been connected and how much data it's used. All sessions next to it is the history, with the reason each one ended.

This is different from the authentication log. The log records a decision: this certificate was accepted at 09:53. A session shows a connection that is still up. A laptop that authenticates once and stays connected all week is one line in each.

Where it comes from. The client's own equipment tells us through RADIUS accounting. It sends a message when a device connects, updates while it stays connected (usually every five minutes), and a message when it leaves. Passbeam keeps one row per session and updates it.

It needs accounting turned on, which is the same two server lines you added for authentication. See “Sessions are empty. What do I need to turn on?”.

There are four states. Connected means nothing says otherwise. Ended means the equipment told us the device left, and why. No recent update means equipment that had been sending updates has gone quiet for too long, usually because an access point was unplugged or a switch restarted. It doesn't mean the device left, because we can't know that.

Superseded is the fourth. Some switches open an accounting session for one step of an authentication, like a MAC check, then leave it when the device passes 802.1X a few seconds later, without ever closing it. When a newer session arrives for the same device on the same switch, Passbeam closes the older one and marks it Superseded, so you can tell it apart from one the equipment ended.

Each row can also have a Disconnect button, which ends that session on the client's equipment. It needs a connector at the site. See “How do I disconnect a device that is already connected?”.