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A DIY-solution is nice (and as engineers something really fun to do) but they will have to maintain it in the future and this is not necessarily "future proof".

by Loic 10y ago

A DIY-solution is nice (and as engineers something really fun to do) but they will have to maintain it in the future and this is not necessarily "future proof". They would have simply put some KNX[0] compatible components in the system, they would have had control of everything using an open standard. They could have connect light, security cams, door locks, the power plugs, etc... and because this is a standard, the day they move out of the office, they will be able to resell the system to the next users. [0]: https://knx.org https://knx.org

eveningcoffee 10y ago
KNX would be definitely a choice but you have to be careful and shop around as many KNX manufactures are known to be incredibly greedy. The situation has improved a lot in recent years though. Also the term open is very relative here (you have to pay a fee (1000 euro + VAT last time I checked) to access the standard, naturally there are no redistribution rights, KNX certification process is order of magnitude more expensive. You need a closed source configuration software to be able to configure the devices. Runs only on Windows (XP did it last time but things may have been changed). A single licence costs 1000 euro + VAT, unless you use limited version that works up to 20 devices and costs 100 euro + VAT (in many small cases that would be enough as the limitation is project based). PS. It is rather an attempt to put things into a contexts than a criticism. Minimum setup: 1) KNX power supply (provides power for the KNX bus), 2) KNX actuator (relay or dimmer or special (say LED stripe)), 3) KNX switch (or an input device (can use standard wall spring switches)), 4) KNX bus connector for programming (USB tongle, KNX/IP router, there are many options), 5) KNX configuration software, 6) Windows machine (VM works too). This setup allows to map the actuator and switch in the configuration software and upload the configuration into the devices. Please also note that encrypted communication between KNX devices is commonly not supported (but so is it also for a simple pulse signal from the wall switch to the relay).
- kamil_gorski 10y ago
  Exactly. Price level of our system is incomparable with same solution based on KNX. Future modifications and changes will be easy even with support discontinuation from our side. Every part of the system is modular - you can pull out RPi with custom modules and place any PLC instead.
- Renaud 10y ago
  Thank you for this clarification. I was interested when the parent mentioned KNX as a standard for these types of setup, but quite disappointed to realise it was another of these "open standards with high barrier of entry". Took me a little while to find out what is was actually about on the website, most pages contains just marketing speak. I wonder if there is any other (really) open standard that could be useful to follow in DIY systems.
  - eveningcoffee 10y ago
    Unfortunately this is the best there is to offer. Worse that could happen is that Google enters into this market.
- Loic 10y ago
  The first configuration is pretty simple and the 1000€ license is just to "build" the elements into your office/house. Once they are setup, you do not need the license and can control everything with fully open source software. The hardware is now easy to buy and not that expensive at all[0]. You practically never pay the 1000€ because it is owned by the company putting the cables in your home. But, yes, you have this software fee if you want to change the hardware on a regular basis (but I must say, I don't know anybody doing this). [0]: http://www.eibmarkt.com/ http://www.eibmarkt.com/
  - eveningcoffee 10y ago
    You definitely can manage to have a reasonably priced solution. But it is not dirt cheap as some Raspberry Pies and relay boards.
    - Loic 10y ago
      We both agree, but my point was more to think "future safe". You do not rebuild your house/office every 12 months like some people are rebuilding their app with every new framework coming out on the market.
      - eveningcoffee 10y ago
        I completely agree with this.
fit2rule 10y ago
>will have to maintain it in the future and this is not necessarily "future proof" Sorry, but no. The reason to DIY is that you can continue to maintain it properly as you go along.

by Loic 10y ago

eveningcoffee 10y ago

KNX would be definitely a choice but you have to be careful and shop around as many KNX manufactures are known to be incredibly greedy. The situation has improved a lot in recent years though. Also the term open is very relative here (you have to pay a fee (1000 euro + VAT last time I checked) to access the standard, naturally there are no redistribution rights, KNX certification process is order of magnitude more expensive. You need a closed source configuration software to be able to configure the devices. Runs only on Windows (XP did it last time but things may have been changed). A single licence costs 1000 euro + VAT, unless you use limited version that works up to 20 devices and costs 100 euro + VAT (in many small cases that would be enough as the limitation is project based). PS. It is rather an attempt to put things into a contexts than a criticism. Minimum setup: 1) KNX power supply (provides power for the KNX bus), 2) KNX actuator (relay or dimmer or special (say LED stripe)), 3) KNX switch (or an input device (can use standard wall spring switches)), 4) KNX bus connector for programming (USB tongle, KNX/IP router, there are many options), 5) KNX configuration software, 6) Windows machine (VM works too). This setup allows to map the actuator and switch in the configuration software and upload the configuration into the devices. Please also note that encrypted communication between KNX devices is commonly not supported (but so is it also for a simple pulse signal from the wall switch to the relay).

kamil_gorski 10y ago
Exactly. Price level of our system is incomparable with same solution based on KNX. Future modifications and changes will be easy even with support discontinuation from our side. Every part of the system is modular - you can pull out RPi with custom modules and place any PLC instead.
Renaud 10y ago
Thank you for this clarification. I was interested when the parent mentioned KNX as a standard for these types of setup, but quite disappointed to realise it was another of these "open standards with high barrier of entry". Took me a little while to find out what is was actually about on the website, most pages contains just marketing speak. I wonder if there is any other (really) open standard that could be useful to follow in DIY systems.
- eveningcoffee 10y ago
  Unfortunately this is the best there is to offer. Worse that could happen is that Google enters into this market.
Loic 10y ago
The first configuration is pretty simple and the 1000€ license is just to "build" the elements into your office/house. Once they are setup, you do not need the license and can control everything with fully open source software. The hardware is now easy to buy and not that expensive at all[0]. You practically never pay the 1000€ because it is owned by the company putting the cables in your home. But, yes, you have this software fee if you want to change the hardware on a regular basis (but I must say, I don't know anybody doing this). [0]: http://www.eibmarkt.com/ http://www.eibmarkt.com/
- eveningcoffee 10y ago
  You definitely can manage to have a reasonably priced solution. But it is not dirt cheap as some Raspberry Pies and relay boards.
  - Loic 10y ago
    We both agree, but my point was more to think "future safe". You do not rebuild your house/office every 12 months like some people are rebuilding their app with every new framework coming out on the market.
    - eveningcoffee 10y ago
      I completely agree with this.

fit2rule 10y ago

>will have to maintain it in the future and this is not necessarily "future proof" Sorry, but no. The reason to DIY is that you can continue to maintain it properly as you go along.