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Hi all,
could you point me on some cheap DIN-Rail KNX devices with many inputs/outputs. So far the cheapest modules I've found are from MDT Automation:
16 Inputs
16 outputs

Are there any cheaper KNX solutions?

Eibmarkt links do not work (you actually should replace the session id in the url with the valid one but I do not bother and I'm using eibhandel.de instead).

With inputs it depends what voltages you need. I guess that you want to connect switches? Then MDT is not a good option. With a bit more money you can get ABB UK/S32.2 Universal that provides 32 inputs (can be configurated also as outputs (I believe that to drive small LEDs)) - http://www.eibhandel.de/ABB-UK-S322-Uni ... nz-32F-REG.

Thank you for the answer and sorry for the links. Yes, I need the input module for button switches and window sensors. The 32 I/O module you point me seems exactly what I need and the price is acceptable (for a KNX module ).

Do you know some relay output module for 16 outputs or even more? 10A per channel is more than enough. I'm searching the lowest ratio price per channel. In fact, I'm searching help for finding these modules:
- Multi-channel 220V relay module, 16 or more 10A channels (so far I've found this to be the cheapest module - MDT AKK-1610.01)
- 4 channel dimmer, incandescent dimming or LED dimming (maybe there's a universal dimmer?)
- 4 channel shades shutter actuator (so far I've found this to be the cheapest module - MDT JAL-0410.01)
- some kind of central heating control for 5 (or 4 points if the price is too high for 5). I don't need fancy wall thermostats, I just need a DIN module for temperature sensors and thermostat logic (or maybe I could do the logic in some application software that drives relays?). I'll drive 220V thermo-valves.
- Some cheap KNX gateway (USB or Ethernet)

Do I miss something essential for a KNX installation?

mishoboss wrote:some kind of central heating control for 5 (or 4 points if the price is too high for 5). I don't need fancy wall thermostats, I just need a DIN module for temperature sensors and thermostat logic (or maybe I could do the logic in some application software that drives relays?).

You can consider Zennio QUAD (http://www.voltus.de/schalterprogramme/ ... ngang.html) for temperature measurments and temperature control (this works with Zennio propiertary but cheap NTC sensors) and Theben 4910210 HMG 4 (http://www.eibhandel.de/Theben-4910210-HMG-4-KNX) to drive the valves (NB! cheaper HME (http://www.eibhandel.de/Theben-4910211-HME-4-KNX) is an extension module).

mishoboss wrote:Do I miss something essential for a KNX installation?

Yes. A power supply.

kris2lee wrote:Yes. A power supply.

Do I have to buy a KNX power supply or a regular 24V power supply works too?

Anybody? I'm still searching for KNX modules with best ratio of price/functionary. So far I have found these modules:

- 32 I/O module for buttons, switches and LED indication - 343,57 € (relatively nice price ratio)
- 16 channel 10A per channel relay module - 281,00 € (nice price ratio)
- 4 channel shutter/shade module - 186,00 € (nice price ratio)
- 4 250W dimmers - 327,00 € (huge price just for 4 dimmers, there has to be more affordable option)
- KNX IP Gateway - 194,00 € (is there any cheaper way to talk to the KNX bus... 200 € just for dumb gateway is way too much for me)
- Zennio 4 sensors input for temperature measurement - 101,15 € (as far as I read the maximum cable length for the sensors is 1,5m, I need about 10m)
- 4 thermo-valve controller - 169,54 € (do I need this, or I can drive relays from the relay module?)

Also, do I need a special KNX power supply, or I can use any power supply for 24V? Is there anything special about KNX power supplies? (I'm searching for the reason why they cost several times more than regular 24V power supply).

I'm taking any advices and suggestions. Thanks.

You can use the EIBmarkt IP PoE gateway for €149, or the USB version for €125.
http://www.eibmarkt.com/cgi-bin/eibmark ... DE_N000401
http://www.eibmarkt.com/cgi-bin/eibmark ... DE_N000403

For i/o you can have a look at ABB, I use the US/U4.2 but you can find several types and functions within that range.

Depending on your system you'll also need a choke. EIBmarkt also has a few starter kits with some of the components you need, you might save some money. Example:
http://www.eibmarkt.com/cgi-bin/eibmark ... =DE_e163_2

You can also use bus connected sensors from Elsner or Arcus, the only limit is your bus cable length.
http://www.arcus-eds.de/knx-sensorik-te ... lima0.html
http://www.elsner-elektronik.de/knx-sensor20.html

Yes you need a special 24V KNX powersupply. I sugest you read the KNX documentation (order the books) from KNX. They will shed some light on the darknes of KNX. Roughly seen, KNX uses the same principal as Powerline (X10 over powercables). Although it uses different methods and it digital. Among other things, the powersupply makes sure you will not have interference from the net and makes your network stable.

Don't forget to buy a copy of ETS if you want to program your system.

Thank you, Post-IT.
I like the EIBmarkt IP Gateway. It has also input for external power supply and I think I could use that way any power supply from 12V to 24V DC. As far as I understood from the module documentation. Please, correct me if I'm wrong.

About the 1a EIB KNX Basispaket PRO, I don't think it's gonna be cheaper that way. The modules they offer cost more even with the discount, than these I've found so far.

The Arcus and Elsner have not so cheap sensors. Is there a KNX module that can read 1-wire temperature and humidity sensors? The other way is to work with 1-wire, but on a higher level with some PC software.

I know about the ETS license (these guys just don't want KNX to rule the mass market...). I think I could use the ETS demo version that can program up to 3 devices. I will have 6-7 devices anyway.

My goal is to make the whole home automation with KNX for less than €1500.

mishoboss wrote:Is there a KNX module that can read 1-wire temperature and humidity sensors?

There is a product named Wiregate but it is quite expensive (about 300 euro) so I think that it defeats the purpose. Voltus has Elsner temp+rH sensor http://www.voltus.de/schalterprogramme/ ... uchte.html with cheaper price than eibhandel.de but it is still quite expensive. When you do not need too many rH sensors then it might still fit your budget. Relative humidity sensors are quite expensive anyway. But you probably have to calculate that what makes more sense for you.

mishoboss wrote:I know about the ETS license (these guys just don't want KNX to rule the mass market...). I think I could use the ETS demo version that can program up to 3 devices. I will have 6-7 devices anyway.

When you only have 6-7 devices then you can also buy ETS light license that is "only" 100 euro (+VAT).

Thanks, kris2lee.

A pretty good 1-wire temperature and humidity sensor costs less than $10 - DHT22. A 1-wire USB dongle costs about $15. I don't know why in KNX world everything has to costs a man's half family. Also I'm using Italian wall switches (Vimar) and these sensors with cover plates don't fit to me. What I'm searching is just the KNX DIN-Rail module with input for 1-wire bus. I have found too Wiregate, but the price is too KNX style. I continue searching, there has to be something more affordable (i.e. not so overpriced).

I know the ETS light license, but I would like to avoid paying the 100 euro license. I think I could program my 6-7 devices in 2 separate projects. If I can't then I'll buy the license.

P.S. What about the EIBmarkt IP Gateway power supply input? Can I use a regular power supply (not KNX) with it? It seems so, as far as I understood from the documentation, but German is not my native language

Pay attention to the following: single wire interface is not the same as (Maxim) 1-wire interface...
Read the comments on the Sparkfun site

Yes, my mistake. Thank you, Digit.

Anyways, there's an Arduino library for reading it, so it stays an option as I have some Arduino experience.

mishoboss wrote:Zennio 4 sensors input for temperature measurement - 101,15 € (as far as I read the maximum cable length for the sensors is 1,5m, I need about 10m)

I think that this is not true. Check this http://www.zennio.com/images/stories/ze ... ng_Ed1.pdf
It says that maximum lenght for the cable is 30 meters.

Thank you, Kris. However I bought one Arduino UNO, Ethernet Shield and 7 DHT22 sensors and I will make temperature and humidity measurement on 7 points in my apartment for less than 130€, and talking to me via TCP/IP.

However I still search for cheaper KNX stuff, especially dimmers. So far the best price ratio is for this 4 channel dimmer from MDT for 327€. The draw-back here is that it's only 250W per channel, but I will use only LED lights and I think it wouldn't be a problem. However this price is killing me.

Are there any other 32 channel I/O modules except ABB UK S32.2? Or any other better price ratio option (price per channel)?
Are there any other multiple channel relay modules with better price ratio (price per channel) than MDT 16 channel 10A module?

And the other question, that I still don't have an answer - can I use the EIBmarkt IP Gateway with a regular 12-24V power supply (not KNX)? It seems It could be done, since the module provides inputs for external power supply and this could be used to power the whole KNX bus.