Tweety is intended to provide a lean KNXnet/IP Tunnelling server. It is intentionally restricted to PEI 16/EMI 1, since this choice allows it to offer both BCU 1 and BCU 2 support with a single code base. One single client at a time is supported. Tweety does not support EIBnet/IP Routing.
Eibd started out as a simple KNX/EIB network access server for the BCU SDK, but has evolved into a powerful daemon supporting a variety of protocols. KNX/EIB access is possible via a BCU 1 (and a Linux low-level driver), a BCU 2, USB, the TP-UART host protocol, EIBnet/IP Tunnelling and EIBnet/IP Routing. Clients can connect to eibd via the proprietary eibd protocol or via EIBnet/IP Tunnelling and Routing.
For the eibd protocol, a C library is available that simplifies writing client programs. Various network management tools are available as examples. Note that these programs always need eibd to connect to the KNX network since they only know the eibd protocol.
While Tweety prepares the address table length of the interface BCU on its own, eibd uses a separate tool for this purpose. To make things easier, eibd comes with its own setup wizard (accessible via the KNXLive! menu).
The Tweety Documentation also contains some background information about EIBnet/IP.
The BCU SDK homepage
BCU SDK documentation, Sections 7 and 10
Open-source foundations for PC based KNX/EIB access and management -
Presentation given at the 2005 Konnex Scientific Conference including information on Tweety and eibd.
An unsolved mystery
At least on our test system, the group monitor feature of ETS 3.0c and ETS 3.0d behaves erratically when using EIBnet/IP for bus access. Frequently, the traffic log window remains empty although Write_Group requests transmitted via the "Send" button properly appear on the bus. Since this happens as well with the Siemens N146 as EIBnet/IP server, we do not think the problem lies with Tweety/eibd.