MTN647091 does not give 0-10 voltage on analog output

[PiotrJakubczyk]

Hi 

Is it normal that our product from box does not give 0-10V (knx line connected), relay is working when controlled over KNX?

I have MTN647091  on my desk and I'm measuring voltage on + and - (nothing connected)

Nothing mentioned about other connection options.

I want to control 0-10 valve. 

[Thomas_Rohde]

Hello Piotr!

I think you try to use the device in way where it is not made for.
As you say, you can measure a voltage and this is what the device is made for => Interface!
So it provides only a certain voltage with a minor current.
Other devices with, with the 0-10V INTERFACE, just use the voltage level to identify the correct dimming level.
So it is not made for to deliver a certain power to drive a valve.

[PiotrJakubczyk]

Key point is not explained that in our KNX offer there are two kinds of analog outputs passive and active. Now if someone by mistake bought MTN647091 (passive) but needs active MTN682291 he needs use bellow application note. 

I'm from HVAC business and for 10 year I don't have contact with something like active 10 V actuator (maybe they don't exist). But in lightning business I read that it was common practice to use active 0-10 V actuators. Learning is expensive ; )

[Thomas_Rohde · Accepted solution]

Hi Piotr!

Ahh, I mixed it up! 
The interface does not give a voltage out! But it "controls" so to say the voltage.
Means, the device is acting like a kind of resistor. And with this resistor handling it drives the voltage which is comming from other devices (like a lamp with the dedicated interface).

So it is correct that it does NOT provide a certain voltage.

The correct device, and this is what I had in mind, is the Analogue Actuator (MTN682291).