PS=1 Max modulation (ID=14) always 0%

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Moderator: hvxl

PS=1 Max modulation (ID=14) always 0%

Postby mminehan » Mon Mar 11, 2019 2:05 am

I wonder if someone can help with reading the maximum relative modulation setting with the PS=1 command.
I can set the maximum relative modulation using 'MM=xx' and the gateway responds. The monitor program gets the reading:

13:54:37.797366 R100E2800 Write-Data Maximum relative modulation level: 40.00
13:54:38.033063 BD00E2800 Write-Ack Maximum relative modulation level: 40.00

But when I issue a PS=1 command the data says max modulation is 0.00%:

13:56:10.539389 00000010/00000000,0.00,00000011/00000011,0.00,0/0,0.00,0.00,0.00,0.00,34.90,67.80,0.00,0.00,55/35,45/25,55.00,44.00,0,0,0,0,0,0,0,0

I have tried AA=14, hard resetting the gateway, soft resetting the gateway etc. But always the PS=1 reports the max rel modulation as 0.

Is there something I am doing wrong?

Thanks, Marty.
mminehan
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Re: PS=1 Max modulation (ID=14) always 0%

Postby hvxl » Mon Mar 11, 2019 4:40 pm

You're not doing anything wrong. Everything sounds like it behaves exactly as it is supposed to.

See also https://www.domoticaforum.eu/viewtopic.php?f=75&t=11515
Schelte
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Re: PS=1 Max modulation (ID=14) always 0%

Postby mminehan » Mon Mar 11, 2019 5:24 pm

@hvxl Thanks for pointing me to an explanation. I'll have to try and find another solution.
We have a 'Radiant' (italian) combi boiler for DHW and CH that an Opentherm compatible controller (Digitech MIAH4). The CH is controlled by a simple contact closure relay from the manifold, not Opentherm. So the CH is either off or on (100% modulation).
I have HomeSeer and the script uses the PS=1 command to get the values. This means I can't get the correct max modulation into HomeSeer using PS=1.
I'll have to workout another way, either decoding the HEX messages or find a thermostat that supports DHW, CH and has a contact closure input for CH to connect to the existing manifold.
I'll keep experimenting.
Marty.
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