Profilux II plus aquarium controller

[Matthias Gross]

niloc16,

i think i found the mistake.
Cable ProfiLuxTunze1 uses L1 (or L3 when used in L3L4), cable ProfiLuxTunze2 uses L2 (or L4 when used in L3L4). So we have two different Tunze-cables, they can be connected to one port (eg L1L2) using an Y-adapter, then L3L4 would be free for other purposes.
That means in your case: 1-10V port 1 (=L1) and 1-10V port 4(=L4!) should have function pump 1 and pump 2! (Assuming you connected Tunze1 to L1L2 and Tunze2 to L3L4, otherwise we talk about the 1-10V-ports 2 and 3).
So please configure 1-10V-interface 4 - then it should run.