OTGW with Atag One thermostat and Atag I36C boiler

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OTGW with Atag One thermostat and Atag I36C boiler

Postby marcv » Sat Mar 24, 2018 2:16 pm

I hooked up an OTGW (with esp8266) from Nodo shop to my Atag boiler and Atag One thermostat. In gateway mode it is working as it is supposed to. However in monitor mode it stops working with lots of errors 3. Also in gateway mode after a few hours my thermostat looses connection with the boiler without restoring the connection (and no error messages in otmonitor). I think it might be a timing problem. I did some testing:
Code: Select all
1. LED test
2. Bit timing thermostat
3. Bit timing boiler
4. Delay symmetry
5. Voltage levels
6. Idle times

The outcome of test number 2 seems to be ok.
The outcome of test number 3 is not.

Enter test number: 3
60402,1036,4080,1040,4081,1040,4081,1041,4079,1041,4081,1041,4080,1040,4081,1041,4080,1041,4080,1041,4080,1041,4080,1041,4080,1041,4080,1041,4080,1040,4080,1041,4080,1041,4081,1040,4080,1041,4080,1040,4081,1041,4080,1041,4079,1041,4080,1041,4080,1041,4080,1041,4080,1040,4081,1040,4081,1040,4081,1041,4079,1040,4081,1041,4080,1040,4081,1041,4080,1040,4081,1040,4081,1040,4081,1040,4080,1041,4080,1050.
Error 03
1040,4081,1040,4081,1040,4080,1040,4082,1040,4080,1040,4081,1040,4081,1041,4080,1040,4081,1040,4081,1040,4081,1041,4081,1039,4081,1040,4081,1040,4081,1040,4081,1040,4081,1039,4081,1041,4080,1040,4081,1040,4081,1040,4080,1041,4081,1039,4082,1040,4080,1040,4081,1040,4081,1040,4081,1040,4080,1050,4071,1040,4081,1040,4081,1040,4081,1040,4081,1040,4081,1040,4081,1040,4081,1040,4080,1041,4080,1041,4081.
Error 03
1039,4082,1040,4081,1040,4080,1040,4081,1040,4081,1040,4081,1039,4081,1040,4081,1039,4082,1039,4081,1040,4081,1040,4081,1040,4081,1040,4080,1040,4081,1040,4082,1039,9682,493,2537,998,6072,998,5567,493,517,493,1527,493,517,493,1022,998.
Error 03
530,1031,1042,476,549,475,548,1007,508,516,508,526,498,516,1042,1040,474,534,1025,1006,1042,476,549,475,549,1006,508,516,508,517,507,516,508,517,507,517,508,517,507,516,509,516,508,524,500,576,448,516,508,516,508,516,580,445,508,517,1019.
70970000  Unk-DataId  Message ID 151: 0
59.
494,516,494,2536,75,9016,493,517,493,517,493,517,493,517,493,517,494,516,494,516,494,516,494.
Error 03
529,1032,1042,1007,507,517,507,517,507,517,517,507,564,460,1042,1007,566,458,507,517,508,516,508,516,508,516,508,517,507,517,507,517,508,516,1042,478,547,475,549,1006,1042,476,548,476,548,1007,553,471,508,516,507,517,1113,406,548,470,531,35106,75.
Error 03
59.
59,951,75,936,75,935,75,936,75,935,75,936,75,935,75,936,75,1440,75.
Error 01
59.
59,1457,75,935,75,936,75,935,75,936,81,930,513,1002,75,1441,75,936,75,935,75,936,75,935,75,936,75,936,509,501,75,936,75,935,75,936,75,935,75,936,75,935,75,936,75,936,505,505,75,936,504,506,75,936,503,507,75,936,75,1440,75,31969,538,1024,1042,1006,507,517,508,517,507,517,507,517,508,540,1018,1007,507,614.
Error 01
59.
59,952,75,935,75,936,502,508,75,935,75,936,75,935,75,936,75,935,75,935,75,936,75,935,75,1441,75,935,75,1441,75,935,75,936,75,935,75,936,495,515,75,935,75,936,75,935,75,936,75,935,75,935,75,936,75,935,75,936,491,1024,75,47042,529,1031,1043,1006,507,517,507,517,507,517,508,525,499,517,507,517,507,517.
Error 01
59.
59,952,75,935,75,936,75,935,75,936,490,520,75,935,75,936,75,935,75,936,75,935,75,1441,75,935,75,1441,75,936,486,524,75,935,75,936,75,935,75,935,75,935,75,935,75,935,75,935,75,935,75,935,75,936,485,525,75,935,75,1440,75,59574,530,500,549,475,549,1007,507,516,508,517,507,517,508,516,508,516,565,459.
Error 01
59.
59,951,75,935,75,936,75,935,75,935,75,935,75,1440,75,1440,75,936,485,525,75,935,75,935,75,1440,75,1440,75,935,75,935,75,935,75,935,75,935,75,935,75,935,75,935,75,936,485,525,75,935,75,935,75,935,75,935,75,1440,75,10663,530,501,548,476,548,1007,507,517,508,516,508,525,499,517,507,517,1080,969,507,517.
Error 01
59.
59,1456,75,936,75,935,75,935,75,935,75,935,75,935,75,935,75,936,485,525,485,525,485,525,75,935,75,935,75,935,75,935,75,935,75,935,75,935,75,935,75,1440,75,1440,75,935,75,935,75,936,485,525,485,525,75,935,75,935,75,1440,75,21965,529,501,548,476,549,1006,508,516,508,516,508,516,508,517,507,517,555,469.
Error 01
59.
59,1457,75,1440,75,1441,75,935,75,935,75,935,75,935,75,935,75,935,75,936,485,525,75,1439,75,1441,75,935,75,935,75,935,75,935,75,935,75,935,75,1440,75,1440,75,1440,75,935,75,1440,75,935,75,935,75,1440,75,37575,528,1032,1042,1007,1042,1007,506,518,507,527,497,517,507,526,499,589,434,519,506,517,507,519,505,518.
Error 01
495,1066,1007,1042,1007,1042,472,551,473,552,473,551,532,492,473,551,472,552,533,491,473,551,474,551,1007,1042,473,550,473,551,473,552,473,551,473,551,473,552,472,552,1007,1041,473,551,1008,510,514,1041,473,551,474,550,474,629,906.
50020130  Write-Ack   Master configuration: 00000001 48
494,1067,1006,1042,472,552,472,553,472,552,472,591,433,552,472,552,1052,466,513,511,514,1041,472,552,1007,511,514,1041,472,552,473,552,472,553,471,552,473,551,473,551,473,552,472,552,473,559,465,601,423,552,472,552,472,552,498,526,473,553,983.
40730000  Read-Ack    OEM diagnostic code: 0
481,576,473,522,503,1041,1007,1042,471,553,472,552,472,552,529,495,472,553,472,552,568,456,472,552,473,552,472,552,1007,1042,472,552,472,553,471,553,472,551,473,552,472,552,472,552,472,553,472,552,472,552,475,550,532,491,473,552,472,552,474,551,984.
D0010000  Write-Ack   Control setpoint: 0.00
492,1068,1006,1043,1005,1045,469,553,472,577,447,552,472,553,471,583,441,553,575,449,1007,511,513,511,513,1042,472,552,1006,512,513,1042,471,564,995,1043,471,553,471,553,471,553,472,613,411,552,473,552,472,552,488,536,472,554,983.
500E6400  Write-Ack   Maximum relative modulation level: 100.00

Enter test number: 4
OK1A high-to-low: 14us
OK1A low-to-high: 25us
OK1B high-to-low: 6us
OK1B low-to-high: 5us

Enter test number: 5
Thermostat: 0.88, 2.27
Boiler: 0.00, 4.14
Reference: 1.22

What could be the cause of my lost connections?
marcv
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Re: OTGW with Atag One thermostat and Atag I36C boiler

Postby hvxl » Sat Mar 24, 2018 8:28 pm

This almost looks like the boiler is trying different protocols to get communication going. For opentherm the timings should only show values of around 500 and 1000 µS. The first couple of lines show timings of 1000 and 4000 µS. Then you get a few that sort of start to look like opentherm. But before things have a chance to synchronize, it switches to yet another protocol that uses pulses of 75 µS. Near the end things appear to have settled down and you're getting valid opentherm messages.

Maybe the boiler is confused by your experimentation. You can try to power down the boiler, connect everything in the mode you want to use it, power up the gateway, and then switch on the boiler again. I would also suggest to check the manual of the boiler to see if there is a setting for the protocol to use. Hopefully you can switch that from auto-detect to opentherm.
Schelte
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Re: OTGW with Atag One thermostat and Atag I36C boiler

Postby marcv » Sun Mar 25, 2018 12:40 pm

Thanks for your reply Schelte.

I used to start my OTGW first and then start the boiler. I'll give a reverse start a try.

On this forum i read about the voltage regulator getting very hot (which is what i'm experiencing also; on average my OTGW with esp8266/nodemcu draws around 100 mA; my external power supply is set to deliver 20V. So my voltage regulator has to dissipate around 2W of mostly heat) and i was thinking the produced heat influenced the optocouplers (resulting in bad readings) so i measured the temperature of the OTGW-board within the enclosure. After a while temperature seems to stabilize around 33C. I don't think this might be an issue.

I'll dive into the specs of my boiler.
marcv
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Re: OTGW with Atag One thermostat and Atag I36C boiler

Postby marcv » Sun Mar 25, 2018 1:52 pm

Found some specs.
Atag advises an OpenTherm Low Power Adapter to be installed between boiler and OT thermostat.
Could low power (specs OT 3.0?) influence communication between OTGW and Atag boiler?
marcv
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Re: OTGW with Atag One thermostat and Atag I36C boiler

Postby hvxl » Mon Mar 26, 2018 4:45 pm

The Atag I36C installation manual indeed indicates that you need to install an OT-LPA if you want to use an Opentherm thermostat. That suggests that the Atag One doesn't communicate with the I36C using Opentherm. But in your experiments you saw proper Opentherm communication between the OTGW and the thermostat. So apparently the Atag One will switch to Opentherm when necessary. I didn't find any specifications online that actually state that the Atag One supports Opentherm.

Normal (pre 3.0) Opentherm uses low power. Medium and high power modes were added in OT specs 3.0. The OTGW will not request medium or high power from a boiler (it can provide it to a thermostat, though). So low power is the standard.
Schelte
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Re: OTGW with Atag One thermostat and Atag I36C boiler

Postby marcv » Mon Mar 26, 2018 7:05 pm

Schelte,

Today i noticed the opentherm low power adapter is already in place when you buy an I series boiler from Atag. So you don't have to buy it seperately.
It's not connected though. The opentherm low power adapter can be found at the back of the control board inside the boiler.

Hooking up the OTGW to the boiler through the opentherm low power adapter did not improve the connection between boiler and thermostat. Same problem:
-gateway mode works fine for a while, then the Atag One looses connection with the boiler;
-monitor mode does not work (lots of error 3).
One would expect it to be the other way around: monitor mode works, gateway mode doesn't.

I found some documentation stating that the boiler does indeed support OT. I think the problem is with the Atag One thermostat. It does support OT but with some extra signalling. When this extra (non OT) signalling is not recieved by the boiler the Atag One aborts all bus communication.

So, a long story short: best changes to get the OTGW working with an I series boiler from Atag one should not buy the Atag One thermostat.
marcv
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Re: OTGW with Atag One thermostat and Atag I36C boiler

Postby hvxl » Mon Mar 26, 2018 8:01 pm

Without a thermostat connected, the OTGW will start generating its own Opentherm messages toward the boiler. Does communication continue to work in that configuration? That would be a strong indication that your theory is correct.
Schelte
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