The Neets Control system uses Multicast to communicate. This is done on IP address 220.127.116.11 port 7979.
Each control system/extension device sends out a "keep a live" every 3 seconds.
If the control system has not received any message from an extension device for 10 sec it will indicate connection error.
The timeout is an individual timer for each extension device.
The “missing connection” indication will be removed when the connection is established and the extension device is initialized again.
The 10 sec timeout is reset whenever there are communication between the units e.g. when RS232 commands is transmitted or an event is triggered.
The control systems support IGMP, this allows the control system to only receive multicast packages on the address that it need and it also doesn't “Pollute” the entire network like UDP broadcast. In order to use IGMP the switch also need to support this.