KNX communication

[viki2000]

I have seen that since a while are included in FlowCode special communications as DMX-512 and DALI.
Is it any chance to have also KNX?

[Benj]

Hello,

I've looked at the knx.org website and can't really find anything that isn't corporate spiel, though admittedly there is a lot of spiel available to sift through along with lots of unexplained acronyms, pseudonyms and jargon.

Any chance you know the whereabouts of a technical specification detailing the bits and the bytes and their meaning.

The Wikipedia page has been the most helpful so far but that is not detailed enough to base a component on.

[Benj]

Quite amusing, I found a PDF named KNX Specification but then it started out with this.

This document contains the description of the KNX system architecture. It is intended for information before reading the entire specification.

I looked through the document but again there is not enough detail to actually implement anything other than a KNX message consists of less than 255 bytes at 9600 baud and uses twisted pair.

As for finding the mentioned "entire specification" I haven't been able to find anything relevant.

I wonder if you have to sign up and pay a subscription before they tell you how it works. It might also be a closed directory of devices so you have to pay again to add your device to the official KNX range of products.

DMX and DALI are both very well documented which is why they are included in Flowcode. I believe I did support for both buses (master and slave) in an afternoon.

[viki2000]

DMX-512 and DALI components from FlowCode are only the seen part of the iceberg.
If someone wants to implement a slave to control a lighting device, then a lot of code must be written.
Let’s take for example DALI.
We can find on dali-ag.org the user manual free, where a lot of parameters are described:
http://www.dali-ag.org/fileadmin/user_u ... l_engl.pdf
But actually the logic that must be written in code for microcontroller and the hundreds of possible commands that may be implemented are described in standards. The 1st standard is IEC 60929, which was written at that time mostly for electronic ballast for fluorescent lamps. Later the LED drivers became common on market and additional functions/commands were needed, so DALI 2 was released, which is covered by IEC 62386:
http://www.dali-ag.org/discover-dali/da ... rsion.html
As you probably know, the standards cannot be given from one company to another, from one person to another. Each one must purchase his own copy/rights to have them. Nevertheless, if you write “standard 60929” on Google probably you will see some companies that published it illegal online, at least you can see what is required to really have a slave device from code point of view, besides the communication DALI slave component from FlowCode. I think is not so simple.

KNX is more complex than DMX and DALI.
DMX and DALI are suitable for lighting application, while KNX is general for general building automation, which may include lighting, but not only.
Probably you found a simple document about architecture as:
http://www.sti.uniurb.it/romanell/Domot ... 20v3.0.pdf
But if you look here:
http://www.knxuk.org/index.php?option=c ... Itemid=111
You will notice that KNX is covered by a set of standards as CENELEC EN 50090 and CEN EN 13321-1, ISO/IEC 14543-3.
Then is no wonder that you cannot find free info about KNX. You have to buy the standards and inside is described what and how.
Maybe there is only one walk around, but is not sure: to look at the other companies that implemented the KNX stack in their microcontrollers as example and there is described how KNX should be implemented.
I mean something like this:
http://www.ti.com/lit/an/swra497/swra497.pdf
https://www.lpcware.com/content/project ... ontrollers

For example basic info about KNX you may find also here:
http://www.knx.org/fileadmin/downloads/ ... -11-09.pdf
http://www.knx.org/fileadmin/downloads/ ... -11-02.pdf

http://www.weinzierl.de/images/download ... aper_E.pdf
https://pdfs.semanticscholar.org/10b4/6 ... 696116.pdf
http://www.weinzierl.de/images/download ... _Doc_E.pdf

Next company has the know-how. Just go on Products – KNX stacks:
http://www.weinzierl.de/index.php/en/al ... verview-en
http://www.weinzierl.de/index.php/en/download-en

Still, the best is to have the standards in hand.


About subscription and paying a fee, it is similar with DALI as with KNX. You design your device; you write the code and is ready to be sold on market. If you put the logo DALI or KNX on your device, then you must me member of the DALI or KNX association group and you must pay regularly/yearly a certain fee, otherwise your products are illegal and may be subject of penalties. Besides that are expensive dedicated testers, which not everyone has, used to test your device and see if respects the specifications of DALI or KNX communication. Usually people pay a test house for such kind of tests and to get a certificate. And that is besides the fee that you pay to be a member of DALI or KNX. And if you are not member, then you are not allowed to have the DALI or KNX logo on your device
Then comes the control and commissioning software. For DALI there are some free software used for test, installation and commissioning. For example Tridonic offers one for free. You need a PC interface USB-DALI, which is around 200-300€ and their free software. Then the PC behaves as Master and configures the network of DALI devices.
KNX requires and expensive software named ETS, now ETS 5:
https://www.knx.org/no/software/ets/download/index.php
This software requires many times a plugin specific for the device that you want to configure. That is delivered/written by the company who sells the device.
For example, many companies install lighting power supplies with KNX combined with DALI in the same network and they use a kind of converter between KNX and DALI buses. That is called DALI Gateway. It is configured with ETS software from KNX and needs a special plugin under KNX.
It is an expensive and complicate story.

There are different companies that offer USB-DALI interfaces with their own GUI.
For example for Osram you must pay up to 1000€:
https://www.osram.com/osram_com/product ... /index.jsp
https://www.osram.com/osram_com/tools-a ... index.jspR
Regarding the programming, the DALI stack, mostly the companies that manufacture microcontrollers offer info:
http://www.atmel.com/images/atmel-42071 ... t01244.pdf
http://www.infineon.com/dgdl/ap0810211_ ... a308355ccb
http://ww1.microchip.com/downloads/en/A ... 01465A.pdf
http://ww1.microchip.com/downloads/en/D ... 01717A.pdf
http://ww1.microchip.com/downloads/en/A ... 00811a.pdf
General info: https://library.e.abb.com/public/b7e1c2 ... erface.pdf

KNX further links to different projects or apps:
With Google translate from Italian:
http://guidopic.altervista.org/alter/EIBscout.html
http://liwan.fr/KnxWithArduino/
https://media.digikey.com/pdf/Data%20Sh ... valBrd.pdf
https://github.com/lifeemotions/knx.net
http://web.archive.org/web/201403301549 ... endorf.de/
http://www.tapko.de/fileadmin/downloadc ... _stack.pdf
http://www.knx.it/download/Workshop_cos ... ice_v2.pdf

[Benj]

Hi Viki,

Thanks for the explanation, but wow that's a lot of links!

I'm afraid I'm generally pretty busy so I doubt I'll be able to sit down and read all of those. I looked through a few of your links but again didn't find much useful information, The github project was for TCPIP routing and other useful looking bits seems to just contain more spiel.

Do you happen to have a single link that describes the lower OSI layers. That should be all I need to provide a framework that others can use via a component. If they then want to pay to become certified then that's completely up to them.

[Benj]

Aha, this is by far the most promising link yet.
http://liwan.fr/KnxWithArduino/

[viki2000]

You must buy the standards listed above to have access at the needed info.

[Benj]

Thanks Viki,

If you have to purchase the standards to be able to use them then it sounds like we might be breaking their policy to even create a Flowcode component and allow others to use the standard.

Therefore I think for now the answer is no we will not be officially supporting this.

If you wanted to purchase the standards and create your own Flowcode macros or component then that should be allowed.

[viki2000]

No, you do not understand.
You need to purchase the standard to be able to read the information inside, the protocols of communications, specifications and so on...only to get knowledge.
After you have the knowledege, then you have no restriction to use it. You can implement any code, software, stack ...whatever application with microcontrollers you want. You are not limited in any way.
So, making a FlowCode component that supports DALI or KNX is not against any standard or regulation. You need to buy the standards only to get the knowledege/specs.
There are companies that sell KNX stack library.

Maybe I should explain one more time the part with the subscription and fees.
You buy the standards from IEC web store or the standards distributor authoritative body in your country. That is one thing. You need to get the knowledge about how the things are working.
Then you make your own device that is able to communicate over DALI or KNX bus.
In order to sell it and put the logo KNX or DALI on the device, you need a subscription to KNX or DALI "club" and you pay regularly a fee. That is only the commercial side. Then your company is listed on their website and you are allowed to sell your physical device on market. If you sell only software library, then is a different story. Look at these 2 companies for example: http://www.weinzierl.de/index.php/en/al ... -stacks-en and http://www.tapko.de/kaistack.html
In the end your DALI or KNX device must be tested and certified by a test house with specific test instruments. For that you pay other money.

As conclusion, don't worry about making Flowcode components, but be prepared to buy the standards if you want to know how to make them work properly according with the specifications from standards.