Welcome to IfKThenX, a logic layer that extends your KNX system with multi-dependent actions. It enables to define states of a bus, which are then monitored and handled with defined reactions.

---

The idea of IfKThenX is to respond to certain states within a KNX bus system by sending predefined telegrams.

Let's give an example: every time the light in the garage is turned on, you also want to turn on the lights in the courtyard entrance and turn off the lights in the living room. Then the state of turned-on lights in the garage is your condition k. If a condition is matched within the connected bus, the system will write the defined telegrams to the bus, in this case, to turn on the lights in the courtyard and off in the living room.

A k can consist of as many sub-conditions as you want. Another example is that this k has the condition that the light in the hallway is on, and the front door is opened. The corresponding x could be to turn on the lights in the courtyard entrance.

Quick start

You can operate with IfKThenX using the IBusManager service with the concrete type BusManager. Initiate a new IBusManager and inject your ConnectionParameters. A required parameter is the IP address of your KNX-IP interface as a string. That's all you need to get IfKThenX running. Now you can connect to your KNX bus system.

IConnectionParametes connection = new ConnectionParameters("192.0.2.1");
IBusManager bus = new BusManager(connection);
await bus.ConnectAsync();

IfKThenX will automatically start monitoring the bus activity.
Finally, add one or more conditions. A condition is built of two parts, the k and the x. Every k can contain multiple xs. Under the hood, both are different states of the bus. If the state (can be a subgroup of the hole bus) within k is matched, the states in all corresponding xs are activated by sending the needed telegrams.

Let's define a bus state for the k. Here we want to react if the value of the group address 1/1/63 is true (mostly meaning on). It could be that light in the garage.

IBusState kBusState = new BusState();
kBusState.AddOrUpdateState(new State()
{
    Address = "1/1/63",
    Value = new byte[1] { 1 },
    DataPointType = DataPointType.Dpt1
});

All values in IfKThenX are stored as an array of bytes. You have to provide the data point type, at least for states to be written to the bus. But to be consistent, you should always initiate the value. Learn more about data point types at knx.org.

Now you need another bus state that represents the effect of your x.

IBusState xBusState = new BusState();
xBusState.AddOrUpdateState(new State()
{
    Address = "1/1/71",
    Value = new byte[1] { 1 },
    DataPointType = DataPointType.Dpt1
});

Finally, merge everything to a condition and add it to the observing bus manager.

IX x = new X(xBusState);
IK k = new K(kBusState, x);
bus.AddCondition(k);
Console.ReadKey();          // Keep the app running.

With these few lines of code, your KNX bus will behave so that if the value inside the group 1/1/63 is on/true/1, a telegram with the same value will be sent to 1/1/71.
You can add as many conditions as you want. Each one can have as many xs as you wish.

Check out the documentation for further information.

Add IfKThenX to your project

Currently, IfKThenX is not distributed via NuGet.org. Download the latest release and set it as a project reference in your .csproj file like this:

<ItemGroup>
  <ProjectReference Include="path\to\IfKThenX.csproj" />
</ItemGroup>

You can then start using IfKThenX by importing the namespace at the top of your Program.cs:

using IfKThenX;

Dependencies

• Microsoft .NET
• Knx.Falcon.Sdk

Contributions and support

IfKThenX is developed completely open, and your contributions are more than welcome.

Before you start using IfKThenX in any of your projects, please keep in mind that it's a hobby project, and there is no guarantee for technical correctness or future releases.

Since this is a very young project, it's likely to have many limitations and missing features, which can only be discovered and addressed as you use it. It's recommended that you try it out for your specific use case to ensure it supports the features you need.

If you wish to make a change, open a Pull Request — even if it just contains a draft of the changes you're planning or a test that reproduces an issue — and we can discuss it further from there.

I hope you'll enjoy using IfKThenX!