KNX/EIB

The KNX/EIB interface can be connected via Ethernet. You will also find tips and tricks from years of experience here.

Importing a KNX Project

After creating the interface, you can already import a KNX project. If the project was protected with a password, you will be prompted to enter a password. This is then stored in the interface under Advanced.

Tip: After importing, you can create the channels.

Importing a Theben LUXORplug Project

It is possible to directly import a project from LUXORplug. The import is done in the same way as an ETS project. A list of group addresses and trade folders is not generated. For clarity, the sensors have been removed from the building. After importing, you can also create channels.

Creating Channels

In the structure Building and Topology, channels can be created. Various prerequisites must be met for this. It is important to declare the data types in ETS.

Types Prerequisite
Light At least two boolean values.
Dimmable Light At least one bool_dimup value and two uint_byte values.
RGB Light At least two color_3bytes color values. A version with individual channels is not supported at the moment.
Shutter/Roller Shade At least one bool_up value and two uint_byte values.
Shutter with Louvers At least one bool_up value and four uint_byte values.

The values for the status must appear after the send values. The louver function is recognized by the terms slat and lam.

Determining Data Types

The conversion of data types does not work as with other visualizations based on KNX. All KNX data types (DPT) are converted into a PLC format. These can be seen in ETS. Here you will find a complete DPT conversion list.

Tip: Determine all data types in the ETS project before importing. Antcas Control will then resolve them immediately.

RAW Telegram

The raw data type is structured as follows. Each byte in hexadecimal followed by a space:

00 FF 3B

Or a binary value (6-bit) with a leading $-sign:

$3F

Read Requests

Read requests can be evaluated using the read data type. To send a response, an r can be placed directly before the group address. For example: r1/4/23. This sends a response.

The programming is then done as follows. in.switchRead generates an edge that immediately sends the response of the state from the output out.switch.

Note: The group address with the leading r is not listed in the installation.

Variables Offline and Error

There are two variables for diagnosing the interface. The variable offline is true if all gateways have failed or been disconnected. The variable error is true if an interface has failed and operation can still be maintained. With multicast, only the service and not the gateway can be diagnosed. When initializing without a gateway, the variable offline is automatically set to true.

Flow Control

Since the flow control of the gateway only works with unfiltered routers, the number of telegrams and read requests must be set. This should be 100ms per router used. In other words: If 2 routers are addressed simultaneously via multicast, the interval must be 200ms. For larger projects, the read request can also be set higher. Or to approximately 2000ms.

Important Notes

  • Never control security applications via the KNX bus. The bus is not suitable for this. Even a defective motion detector or short circuit due to condensation could prevent the alarm.
  • If the bus is laid in an outdoor area, you should create a new line. This ensures that in case of a short circuit in the outdoor area, the function inside the building is still ensured. Ideally, you can also protect the bus from unauthorized access by setting the packet filter in the line coupler.
  • Pay attention to access security with multicast architectures. Avoid using multicast in public buildings.
  • Since the KNX bus is very slow, you can create multiple filtered lines and have them controlled individually by the server. Make sure that the KNX bus also only has 9600 baud at the network level.
  • Pay attention to loops when routing. KNX has a solution against endless loops with the routing counter, but the speed of the bus will still suffer. In the server, packets are not forwarded internally by default if you use multiple gateways.

Checklist

  • In large projects, the bus length is often forgotten. Always remember that the electrician does not always lay the cables as planned. It can happen that a planned star wiring becomes a daisy chain wiring. The bus can become unstable if the last actuator is more than 1000m away from the power supply.
  • Plan the reserves in the distribution very well. It often happens again that there is not enough space in the distributor for dimmers, etc. Determine the maximum expansion with the customer in the concept to avoid this problem as far as possible.

Troubleshooting

Telegrams are often repeated

If telegrams appear yellow in the ETS group monitor, they are resent due to a packet collision. If this suddenly happens continuously, there may be a defect:

  • Replace the power supply --> Defective filter or choke coil
  • Loop in the bus --> For troubleshooting, you can disconnect at a branch and scan the line.
  • Twisted pair cables were connected to each other --> This creates a loop and must be disconnected. Often found in older installations with U72 cable.
  • Line too long --> Check participant voltage should be at least 24V (KNX is functional up to 21V)
  • Loose contact --> This is very rare and difficult to find.

Invalid Frame - Invalid Frame

If telegrams appear blue in the ETS group monitor, the ETS cannot communicate with the bus. Possible causes are:

  • Check bus voltage --> Short circuit or line too long
  • Replace power supply --> Defective filter or choke coil
  • Defective gateway --> Replace interface

Device cannot be loaded

Try to load the device, if possible with its own power supply, if nothing helps.

  • Restart bus --> Disconnect 230V voltage for 1 minute (also from actuator)
  • Check bus voltage --> Short circuit or line too long
  • Replace power supply --> Defective filter or choke coil
  • Device or bus coupler is defective --> Replace devices
  • Observe group monitor --> Another device can cause interference or there are too many telegrams and the timeouts expire too early (ETS: Device does not respond)
  • Line coupler does not route all telegrams --> Do not load via line coupler

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