Is there any documentation what vmb6pb-20 is exactly designed for? I’m confused a bit. I see it has 6 inputs for buttons (push buttons, switches, anything?) but also 6 outputs for LEDs? It is all together, or one or the other? Or a mix? Considering it’s a velbus device it will have all I can dream of and more, but it would be great to be able to read about it before buying.
“6PB” presumably means six pushbutton inputs, and with optional LED feedback.
I assume the I/O part of it works in a similar way to the older I/O switch modules.
The giveaways are that 1) it does not have 6 extra LED output connections separate from the input connections. and 2) it claims to be able to drive multiple LEDs in both common anode and common cathode configurations.
This tells us that, just like the old VMB8PBU, the LED-drive is a current between two output ports (ie. not a single GPIO ref’d to GND or VCC). The “common” connection can be driven high and used a common anode source to multiple LEDs with their tails pulled low by another GPIO; OR the common can be driven low and the other GPIOs driven high for common cathode.
And then for a very short time every few milliseconds, each GPIO is changed to be an input, to read the status of a switch connected to the input. ie. input and output is multiplexed.
So in normal use the output capability can only really be used to drive LEDs, not as general purpose IO. Not advisable to try to extend the GPIO more than a few cm.
ie. more like a VMB8PBU, not like a VMB7IN.
I can confirm this is how the VMB8PBU operates. BUT I do not have a VMB6PB-20 so I am just extrapolating from what we know. I have not tried a VMB6PB-20 to check this.
TWO SIDES! :-o
and no need for screw terminals either.
So the outputs are really separate. AND it is really small!
I have no immediate need of this but I think I need to get one to play with.
I have just one more question… only six channels… so does it have a further two virtual channels on input and output? ie. so I can set a pushbutton into “multi” mode to switch between other buttons? In that case extra channels are all useful. I already use this feature in several places on VMB8PBU where I used the unconnected channels for “mood/task” lighting programmes.
Just to add to this conversation that we (try to) always document our modules with graphical connection schematics. You can usually find them on the product page under downloads.
We will also release the VMB6PB-21 in 2026 with slightly different connectors. They will use DuraClik Connectors for faster connections. If you have to wire 20x 6PB’s in a house, you tend to want speed over flexibility ;-).
