Document extensions file and FieldPOC controller

docs/reference/controller.md

@@ -0,0 +1,58 @@
+# FieldPOC controller
+
+The FieldPOC controller is an interactive console to help managing the current state of the FieldPOC system.
+
+Connect to it via the IP address von port set in the [FieldPOC configuration](configuration.md) with `telnet`.
+
+## Commands
+
+### Help
+
+`help`
+
+Show help info.
+
+### Show handlers
+
+`handlers`
+
+Show currently running handlers
+
+### Reconfigure all components
+
+`sync`
+
+Notify all parts of FieldPOC to check configuration of connected components and update it.
+
+### Show queue stats
+
+`queues`
+
+### Reload configuration
+
+`reload`
+
+Read [FieldPOC configuration](configuration.md) file and apply it.
+
+### Bind extension to DECT device
+
+`claim <ext> <token>`
+
+- `ext` is the current extension number of the DECT device.
+- `token` is the `dect_claim_token` of the extension that should get applied.
+
+This works because newly connected DECT phones get a temporary number assigned.
+This temporary number is usually the current number.
+But it is possible to use any extension, so the extension for a device can be changed any time.
+
+### Disconnect
+
+`exit`
+
+Disconnect telnet session.
+
+### Stop controller
+
+`stop`
+
+Shutdown the controller, but FieldPOC continues running.