Autor Thema: MAX Radiator Valves  (Gelesen 2935 mal)

Offline Lawrence

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MAX Radiator Valves
« am: 28 Januar 2013, 00:06:16 »
Hi,

I hope someone can help as I am afraid Google's translations are leaving me a little confused.

I was hoping to be able to get regular updates (e.g. every 5-10 minutes) of the current temperature from the MAX thermostats, but a quick read of the logs tells me this isn't the case. I get updates between every couple of minutes to every couple of hours.

I am running the latest FHEM (5.3 development version updated today) on a Raspberry Pi connecting to MAX! radiator thermostats via a CUL (v3) with CULFW (v1.52). Oh yes, I am also very new to FHEM.

The FHEM MAX Wiki (http://www.fhemwiki.de/wiki/MAX) claims the measured temperature can be read but has the following note after it: 'If not using the MAX CUBE regularly updated.' (Google translated and not very clear to me ;-) ).

Is it possible using the MAX radiator thermostats to get regular readings of the current temperature via CUL? If not, would it be possible from the MAX wall thermostats? Or using the MAX CUBE instead of CUL? Or would I have to use a separate thermostat to achieve this?


Thanks in advance for any help and thanks for such a great bit of free software.


Offline Matthias Gehre

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Aw: MAX Radiator Valves
« Antwort #1 am: 28 Januar 2013, 21:06:44 »
Hi,

the firmware in the MAX! thermostats only sends the current temperature if either the desiredTemperature is changed (by the user or FHEM)
or the valveposition is changed (by the controller inside the firmware).
It may be possible to force the thermostats to send the current temperature by sending some special packets to them, but none of this is currently
known.

As this is a problem of the thermostat firmware, it does not depend on whether you use the CUL_MAX or MAXLAN backend.

Offline Lawrence

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Aw: MAX Radiator Valves
« Antwort #2 am: 28 Januar 2013, 21:32:15 »
Thanks for the reply Matthias, I suspected that was the case.

From my reading of the FHEM documentation I believe it isn't possible to use any stand alone thermostats with a single CUL alongside the MAX thermostats due to the rfmode. Is this the case?

I was hoping to use the Heating_Control module to get better control of my central heating, this is beginning to look a little bit more complicated/expensive than first thought :-)
 

Offline Matthias Gehre

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Aw: MAX Radiator Valves
« Antwort #3 am: 28 Januar 2013, 21:35:08 »
You cannot receive the MAX protocol at the same time with any other protocol using only one CUL.

For HeaterControl, I would suggest using external temperature sensors and controlling the MAX thermostat using
the "fake" setters. See the commandref for documentation. Essentially, you can tell them what temperature the room has
and what temperature you want, and the MAX thermostats will then open the valves accordingly.

Offline Lawrence

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Aw: MAX Radiator Valves
« Antwort #4 am: 29 Januar 2013, 00:48:30 »
Thanks for the info,

I have had a bit of a look into the external thermostats and they all have a limitation of the number of devices that can be paired, between 3 and 10.

I have 14 radiators in my house which I was hoping to control them all using the MAX radiator thermostats and a bit of home brew kit for the boiler control. I guess I can get multiple CUL or RFXCOM devices but that is getting quite expensive!

The S300TH sensor looks to be the best option (which works with CUL) but unfortunately can not be bought in the UK :-( the Oregon Scientific sensors also look quite good but they cost more :-( Does anyone have any advice or other options for temperature sensors that poll every 5-10 minutes, even home made ones?

P.s. I knocked together a perl/FHEM script to set a MAX's desired temperature every minute to see how often the actual temperature is returned. The actual temperature only seems to be returned when the valve position changes.

 

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