Values not filled in OpenTherm monitor

[Silent_NL]

Hi,

I’m using the OpenTherm Gateway (software version 4.2) between my Remeha Calenta cw5 and a iSense thermostat. I really like the product! Only thing that I needed to do at first is to set the Voltage Reference to 1.458V (VR=4). Because I got “Error 03” messages in the logs.

I can read all values in the OpenTherm Monitor tool. Except I don’t get values on “Return water temperature” and “Domestic hot water temperature”. And when I check the OpenTherm Monitor message log, I don’t see any entry’s mentioning that values.
But when I check the on my iSense thermostat, I can read that values in the thermostat.

The OpenTherm Gateway is configured as Gateway mode. But I also set him to monitor mode (GW=0), but also then I don’t see the mentioned values getting filled. Does someone have an idea how I can solve this?

[hvxl]

It may depend on the iSense firmware version, but the one I had on loan for a while did request the "Domestic hot water temperature" once ever 12 minutes. It did not normally request the "Return water temperature". Perhaps it only requests them when you access the menu to view these values. I never tested that.

The normal method to obtain values from the boiler that the thermostat doesn't request is to add them to the list of alternatives using the AA command. For the ones you mentioned that would be AA=26 and AA=28.

Note: the AA commands only have effect in gateway mode.

[Silent_NL]

From the moment I did AA=28, I see values coming at the “Return water temperature”. Great! Tnx! I also tried AA=26, but I didn’t see any result on that. The Domestic hot water temperature still doesn’t get any values. How did you know that value? Is there a list of the possible Data-ID’s?

I also check my firmware version of my iSense thermostat, that’s version 28.

[hvxl]

The message ID's are described in the opentherm specification (just google for it).

What value does the iSense show for Domestic hot water temperature? Does it change when you run the hot water tap, or is it really the domestic hot water setpoint?

As I mentioned before, the iSense normally already requests the DHW temperature and the calenta can provide this information, so you should already see it in otmonitor without the need to do anything. If you don't, I'll need a log of 15 minutes to half an hour from otmonitor to investigate further.

[Silent_NL]

I have created a log file with OpenTherm Monitor. See attachment.
I noticed that following entry’s is still coming back:

Code: Select all

11:45:07.330591  R801A0000  Read-Data   DHW temperature: 0.00
11:45:07.388180  BE01A0000  Data-Inv    DHW temperature: 0.00

As if the value is incorrect…

And I checked the iSense, and I see that the value there is also not filled… So I put the OpenTherm Gateway in monitor mode, and I still didn’t see the value “Domestic hot water temperature” getting filled on the iSense thermostat. After that; I bypassed the OpenTherm Gateway, I connected the iSense Thermostat directly on the boiler. But also then; I didn’t see the value “Domestic hot water temperature” getting filled.  (So I was wrong in my opening post…)


Other question, possible related. I connected a DS18S20 temp sensor on the GPIO as mentioned here: http://otgw.tclcode.com/peripherals.html
But that value is not getting filled in OpenTherm Monitor. I see the following error in the log:

Code: Select all

11:45:02.271685  T001B0000  Read-Data   Outside temperature: 0.00
11:45:02.396263  B601B0000  Data-Inv    Outside temperature: 0.00

I configured the GPIO pins with the following settings. GA=2, GB=7 But I believe that are the wrong settings. I think it has to be GA=3, GB=8. Also mentioned here: http://otgw.tclcode.com/firmware.html#configuration
(I’m not really in the electronics) But when I measured the voltage between the GND and the VDD of the GPIO pins, I measured zero volt with the setting GA=2, GB=7. And when I used the setting GA=3, GB=8 I measured 0,87volt. I’m not sure if I did something wrong, or the OpenTherm Gateway is unable to read the temp sensor.

[hvxl]

Data-Inv normally means that the boiler is temporarily unable to provide the requested information, due to sensor malfunctioning or something like that. However, I checked logs that other users with a Calenta have provided and they allways show Data-Inv for the DHW temperature. Possibly the Calenta uses a general interface board that can have a DHW sensor attached that is simply not installed in the Calenta. Or maybe it can only provide a DHW reading when hot water is being used. Have you checked that you don't get a result even then?

Regarding your other question: You conclude that the setting should be GA=3, GB=8 solely on the fact that with those settings you measure 0.87 volt, which is a tiny bit closer to the expected 5V than the 0V you get with GA=2, GB=7? The fact that 0.87V is still nowhere near 5V and you get an error on the GB=8 command doesn't make you reconsider that idea? Then let me clear it up for you: The settings should definitely be GA=2, GB=7. If you don't measure 5V after GA=2, you're either measuring wrong or there's a hardware problem with your gateway.

You can try the following:

• GA=0, GB=0
• Put a jumper on pin 2 and 3 of the GPIO header.
• DP=05
• GA=1
• You should now see that the top two bits of address 05 are 0 (05=XY, where X is 0, 1, 2, or 3)
• GA=2
• Now the top two bits of address 05 are 1 (X is C, D, E, or F)
• GA=0, GB=1
• The top two bits of address 05 are 0 again
• GB=2
• The top two bits of address 05 are 1 again

[Silent_NL]

Oeps… my error. I accidentally switched the GND and the VDD on the DS18S20 sensor.
When I switched the wires, the temp sensor started working!

The reason why I thought it had to be GA=3, GB=8, because I read that on http://otgw.tclcode.com/firmware.html#configuration

Code: Select all

GA=function 
GB=function 
GPIO A / GPIO B - These commands configure the functions of the two GPIO pins of the gateway. The following functions are available: 
1.	No function, default for both ports on a freshly flashed chip. 
2.	Ground - A permanently low output (0V). Could be used for a power LED. 
3.	Vcc - A permanently high output (5V). Can be used as a short-proof power supply for some external circuitry used by the other GPIO port. 
4.	LED E - An additional LED if you want to present more than 4 LED functions. 
5.	LED F - An additional LED if you want to present more than 5 LED functions. 
6.	Home - Set thermostat to setback temperature when pulled low. 
7.	Away - Set thermostat to setback temperature when pulled high. 
8.	DS1820 (GPIO port B only) - Data line for a DS18S20 or DS18B20 temperature sensor used to measure the outside temperature. A 4k7 resistor should be connected between GPIO port B and Vcc. 

But it doesn’t matter. Because it work now! Great!

Regarding the DHW temperature; I also checked the DHW value when I’m using hot water, but still no result. So, you’re possible right; that the Calanta doesn’t have a DHW temperature sensor…

[hvxl]

Apparently your browser is rendering that page wrong. The list starts at 0, not 1. Which browser are you using? Maybe I can investigate if there's something I can change to make it present correctly in that browser too.

Edit: I tried a different method. Does the list start at 0 for you now?

Anyway, great that your issue has been resolved. Thanks for reporting back.

[Templar]

Edit: I tried a different method. Does the list start at 0 for you now?

FYI: I am using Chrome Version 40.0.2214.93 m (64-bit) and the list starts at 0.

[hvxl]

Yeah. According to w3schools.com all major browsers should support both methods I used. So Silent must be using a browser that's even buggier than Internet Explorer