I needed binary inputs which could handle 230 Volt and simply have the option to send On, Off or Toggle to a Group Address using standard light switches with rocker- and push switches. (for a good user experience)
I came across a batch of old SIEMENS N260 4-fold binary inputs, for 10 Euro each, so I bought them,
Just before placing the order I noticed that they have no KNX connector but use a data-rail connection, upon request I got a free piece of data-rail (5WG1190-8AB03) with it.
Problem solved and I could also connect other adjacent SIEMENS modules at the same time.
Looking for the KNX application to load into ETS5 I noticed there are 4 different versions.
Long story short; I experimented with the 'On/off/toggle/Dim/Shutter' version for a long time, and I couldn't select a toggle option so it didn't do what I wanted, bad buy.
But today I again fiddled with them and tried the 'On/off/toggle/cycl' firmware, and low and behold I could just disable the cyclic sending part and the toggle works perfectly, and if I add the Central GA for 'All On/Off' to the object states stay synced nicely!