MAX! Cube LAN Gateway and DHCP

Just when I thought I’d seen the worst, the ELV MAX! system manages to surprise me…again!

Last Tuesday I decided to do a factory reset of the MAX! Cube LAN Gateway; it was impossible to work with. Constantly disconnecting, internal time totally wrong and I couldn’t find any other way to resolve these issues.

Because I didn’t want to spend too much time on this factory reset, I left the MAX! Cube network settings set to DHCP, which I normally don’t do – right from the start, when the Cube was delivered, I assigned a static IP to it, cause all my network devices have a static address.

I configured my DHCP server and created a reservation for the MAX! Cube LAN Gateway, so that although the IP address is assigned by DHCP now, the Cube will always get the same IP address, no matter what.

The next day, I went through the firewall logs. Hey, what’s this… the Cube is contacting an IP address on port 123, which is the IANA assigned port for the NTP protocol! I’ve never seen the Cube doing this, from day 1! Does this mean that…? yes, the Cube now synchronizes the time!

Firewall log of day 2011-11-01 with filter 'xx.xx.xx.xx'.

Nov  1 20:59:58 SRC=xx.xx.xx.xx DST= PROTO=KEY_UDP DPT=123
Nov  1 21:45:58 SRC=xx.xx.xx.xx DST= PROTO=KEY_UDP DPT=123
Nov  1 22:15:59 SRC=xx.xx.xx.xx DST= PROTO=KEY_UDP DPT=123
Nov  1 22:45:59 SRC=xx.xx.xx.xx DST= PROTO=KEY_UDP DPT=123
Nov  1 23:15:59 SRC=xx.xx.xx.xx DST= PROTO=KEY_UDP DPT=123
Nov  1 23:45:59 SRC=xx.xx.xx.xx DST= PROTO=KEY_UDP DPT=123

IP address is where seems to be hosted, the manufacturer of the MAX! system.

Congratulations ELV and/or EQ-3, I found something that does work! 😉 I still don’t understand why the Cube LAN Gateway needs DHCP for that, but I’m past the point of asking myself why every time something doesn’t work on the MAX! heating control system… don’t worry, be happy!

I checked the static IP settings (subnet mask, gateway, DNS) I used and compared them with the DHCP options – they were the same. Of course. I was trying to find out whether I made a mistake or the Cube – silly me!

Another thing that happened was that the sudden disconnections had returned; I hadn’t seen them for a couple of days. Last night, after 00:50, the Cube stopped NTP-ing and some 20 minutes later I got the first socket error 10053 in my Domotica system logs.

Firewall log of day 2011-11-06 with filter 'xx.xx.xx.xx'.

Nov  6 00:20:43 SRC=xx.xx.xx.xx DST= PROTO=KEY_UDP DPT=123
Nov  6 00:50:43 SRC=xx.xx.xx.xx DST= PROTO=KEY_UDP DPT=123
Nov  6 12:50:45 SRC=xx.xx.xx.xx DST= PROTO=KEY_UDP DPT=123
Nov  6 13:20:45 SRC=xx.xx.xx.xx DST= PROTO=KEY_UDP DPT=123
Nov  6 13:50:44 SRC=xx.xx.xx.xx DST= PROTO=KEY_UDP DPT=123

Later that day, I had to power cycle the Cube to get a TCP connection to it that would last longer than 10 minutes… well, nothing surprises me anymore. What’s next?

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19 Responses to MAX! Cube LAN Gateway and DHCP

  1. bernard says:

    Hi Digit,

    I see indeed the postings on the ELV forum that fixed IP address prevents the Cube to get the right time. I guess that’s the reason I have not seen that big timing issues as you did have before, I’m using DHCP with reservations for all network elements except end-user devices. After the firmware update (together with version 1.3.0 and 1.3.1) and the time decoding from mega I’m checking the Cube time and I have not seen a wrong time since then..

  2. Welcome to the wonderful world of MAX! 😉
    I hope I’ve seen all bugs now, all these issues take too much time…

  3. kami says:


    i looking for a little help with the send commands and the MAX Cube. I am trying to run a perl script, which is always checking the mode of the windows contacts and gives back the Temperature of the Thermostats if i give a external command to the script. Can someone tell me, how i can get this information from the cube if i am connected to the cube? So there should be no reconnect to the cube. The Connection is opened and i want to send the commands to get this information. I know the RF-Adress and all of this stuff. But how can i get more informations?

    Thanks a lot for some help 🙂

    Cu kami

  4. kami says:


    thanks a lot for the quick answer. I read all this topics before but i cannot clearly identify how a send command to the Cube must look like to get the informations from the thermostats and windowcontact. I would be really happy if you can help me and send me an Example how to build such a send command. I just want to test the send command on telnet.

    This would be really great.

    Thanks a lot.

    Cu kami

  5. For getting the information from the thermostats and other devices that are teached-in, you only have to send the l: command to the Cube, followed by a CR and LF. The Cube will return a Base64 encoded string, which can be decoded with the information provided in the topics I mentioned above. Look at athe information about the l: response.

  6. You probably already know this, but it seems the 1.3.2 firmware fixes this problem.

    • Yeah I know, this fw update came a bit too late for me, it could have saved me some extra work 🙁
      I haven’t had the time to upgrade to this latest version yet.
      But I expect there will still be some nasty bugs in the Cube which I haven’t seen mentioned elsewhere yet.
      When a TCP connection to the Cube is abnormally closed (for instance by a power failure @ the other side), it takes about half an hour before the Cube accepts a new connection.
      Half an hour… 1800 seconds… ring a bell?
      I think a few more updates will be needed to make the MAX system really reliable…

  7. stephan says:

    I can not get the max cube to connect to internet. And when I do a ping to that address it times out. Is this portal still on that ip address ?

  8. Henk Takken says:


    Does anybody have a script file to read/write the cube parameters like MAX thermostat temperature. Would be great in PHP or Bash or javascript.

    Many thanks

  9. stuart says:

    Are you still using Max! Trvs and the cube ?

  10. olaf says:


    i still have a lot of connection issues.
    i found a a programming/hack site, the following.

    if the java page is open they could not connect. since i had this page open on my server most of the time …

    seems to be working for now, but then again disconnections happen to me randomly it seems.

    others still have this problem ? any permanent fix ?
    for what it is worth check with closing the MAX! java page.

  11. carlos says:


    What is the advantage of having opentherm gateway in conjunction with the ELV max setup?

    I have a similar requirement (10 heating elements with manual thermostat, 1 opentherm boiler + 1 programmable opentherm thermostat), I was looking to replace the regular thermostats with the ELV max system, and perhaps a relay to switch on the boiler on and of when none of the thermostats require heating. This however would mean that there will be no modulation on the boiler. Would that affect a lot with regards to consumption, boiler longevity etc;?

    This also seems an interesting project:

    Many thanks for sharing your setup

    • Robert Hekkers says:

      Because there’s only a single thermostat (in the livingroom) and other rooms might need less heat than the livingroom the valves will close.

  12. Marko says:

    Hi, have there been any updates to the MAX! system? Are the disconnect and time sync issues still there? I’m doing some reading about this system and found some mixed feelings about it.

    Also, I’d like to ask for an advice. Right now I have a central heating system with simple temperature valves and a temperature control unit in living room. Last year I’ve added a fireplace to the living room, which obviously breaks the regulation around the whole house – the living room gets heated up by the fireplace and the control unit shuts down the central heater. So I’ve started looking to smart regulation and found max, which seems quite affordable. What I’m not really sure of is, can I use (out of the box) this system to drive the central heater – so that the remote valves are “saying”, hei box, it’s cold in this room, please turn on the central heater and later or, hei box, me and other valves are all good, you can turn off the heater. What exactly do I need to make this work?


    • Robert Hekkers says:

      Those are gone; you can try influencing the thermostat by manipulating external NTC sensors by adding a Digipot to it.

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