Methods for K8090 object


Latetly I purchased the K8090 kit.

I can program in C# but I don’t understand the DLL user’s guide.

Why does it use methods like ‘K8090.OpenDevice’ and ‘K8090.CloseDevice’ while the code in the samples clearly shows methods like ‘K8090.Connect’ and ‘K8090.Disconnect’

Is there somewhere a correct list of these commands? What is now the right code to make connection to the K8090?
I see no link between the manuals I downloaded from the Velleman Site and Samples 01 & 02, except for the developpers guide which uses other coding than declared in the DLL-documentation.

Thanks in advance,


First of all, there is the file ‘K8090D.dll’. This is a genuine Windows DLL (library) file that can be used to communicate with the K8090 from almost all programming languages. It exports functions like ‘OpenDevice’ and ‘CloseDevice’. This is the most low-level library we provide.

Next, there is an assembly file ‘Velleman.Kits.dll’ for C# or any other .NET language. It is a high-level library specifically created for .NET. It contains a K8090 component which you can drag onto your form and call some methods on like ‘Connect’ and ‘ToggleRelay’.

So, in short, even though they both have the extension ‘.dll’, they are two very different libraries. One is a low-level library, the other is a high-level library for .NET.


I have two more questions:

  1. Where can I find this K8090D.dll . It can’t be found in the software package I downloaded from the Velleman site.Does Velleman still provide this DLL? If yes, where can I find a thrustworthy download site for it?

  2. When you say ‘some methods’, does that mean this component can only handle a few commands (connect, disconnect, toggle relays)? If there are more methods for this component, where can I find these documented?



The K8090D.dll is copied to the C:\Windows\System32 folder for your convenience. That way, the DLL will always be found.

Instructions on the .NET dll are found in its manual:

Start > All Programs > Velleman > K8090 > Samples


Thanks for your support. I can move on with my project.


How are you getting on q
I am too trying to get this working.

Yes it is working.

It’s kindda SCADA system I’m building with it.

What’s your specific issue?