Wire "-" inputs of buttons of several modules together?

I plan to install velbus modules in my new home.
I will have a lot of push buttons directly wired to the inputs of the modules like VMB4RY, VMBDME and VMB2BL.
Is it save to wire the “-” inputs of the push buttons from several modules together?
Can I get somewhere the electronic scheme of the inputs on this velbus modules (optocoupler and there power circuit?)?
Is it so that the “-” of the 12V supply is internally directly coupled to the “-” inputs of the push buttons((ohm measurements indicates that this is the case)?
Erik Baele

Indeed, the “-” of the power supply is also the “common” of the push buttons.

Why wiring the inputs together since you can configure each channel to react to the same push button?
Every channel will react to its own push button but can be configured to react to other push buttons too.


Every channel can react indeed on any of the push buttons of VMB8PB, VMB6IN or VMB8IR modules but not on an other direct hardware push button of the VMB4RY, VMB2BL or VMBDME modules, I presume or am I missing something here?

Wiring the “-” together of different direct harware push buttons, is only to simplify the cabling of the direct hardware push buttons.

The buttons connected to the VMB4RY can be used in your configuration (local button 1,…).

The buttons connected to the VMBDME eg can’t be but you can mount them in parallel since the inputs are “opto coupled”