Hi,

I want to make a little heat controller for my workshop.

I've read a lot about LOGO's and temp. measurement. It looks like i would need an expansionmodule to read a PT100.

However, PT100 have a large temperaturespan, which i don't need. (It will measure room temperature)

I stumbled across Siemens QAA2061, which is a 0-50 C @ 0-10V, which i suppose my LOGO 8 would read? 

Datasheet here; Siemens QAA2061

Questions;

Can I use this sensor with a LOGO8, reading it on an analog input?

Can I "translate" the values to temperature some way, ie. to get a reading on a TDE?

Can I make temp up and down in 0,5C increments using buttons on digital inputs. And further have a button to set a pre-defined night economy mode?

Thanks in advance.

Thanks a lot for a quick reply.

How would i scale the 0-10V input to temperature on the display. I was not able to find that kind of function in LOGO Comfort. I think I need to write a lookup table or similar?

I've got an 6ED1052-2MD00-0BA8 + TDE! + 24V 4A PSU.

A further question the datasheet doesn't answer 100% directly. May i switch 230 VAC on the 24V LOGO! (It is the relay out version)
 

Thanks a lot mate.

Would B012 read 0-5V instead of 0-10V (max value 5000)?. Or do I don't understand the analog inputs.

B009, what does it control? It seems like B008 is what defines the setpoint?

Would really like to understand why it is designed like you did, it will help me edit and create new programs better.

Toogling the reset-pin on B008 could set a night-economy mode at ie. 16C. But i'll have to manually rev the temperature up again. I could not find a way to set ie 16C and 20C switching with a button/DI

EDIT: Is it possible to edit temperature in 0,1C instead of 0,01C? It takes a hell of a time go go from 16 to 20C :)

Thanks for the explanation.

I actually have a 4-20 mA sensor on hand, so I can test the setup, until i order the QAA2061. Can I just flip B012 to 4-20 mA, or would that require more scaling?

As there's only four inputs, and I have to use one for the tempsensor, i have moved temp setting to F1, F2, F3 and F4 of the TDE. Any problems with that?

EDIT: I just saw your new post, as i had posted.

Where did you edit the temp increment to 0,1C? Can't easilly spot the difference from V2 to V3.

You have added connections from I3 to B020 i see. I had figured that out in V2. It'll only raise or lower the temperature, if holded for 1 second or longer. :)

Great forum you have on here.

Ohh, it can't read 4-20 mA directly.

I know about the 500 ohm resistor trick.. I think i will try it out, to se how it works IRL.

I guess i only have 2 DI's when the analog in is enabled? There for i moved them to the TDE.

My memory, lol.. I was sure that it was 4 in 8 out. It's opposite.

However, if i move I1-I4 to F1-F4, and then assign I5 as I1 the night/day selection does not work, whats with that?

Just uploaded the program and the TDE! have white backlight - I can't see any flag for that?

ixo65

Let me take a look at the program you have changed.
Please upload it.

 Shift I5 to I1, and it does not work anymore.. Can't figure out whats going on.

ixo65

You have the background lighting flags inserted into the program, that is not mine.

Sorry - I have inserted the flags later on.. If I use your program, the background is white without any flag?

Doh.. I have figured the mystery out now, regarding I1 and I5.. The display is reading I5, and when i change it to I1, i'll have to change the display setting to.

This should work.

Btw.

I saw a tutorial about the TDE Display..

Ie. Only display the night temp settings, when night mode is selected. And day temps when day mode is selected. Will see if i can figure out how it's made.

Have to learn something my self too :)

I've been quite busy, so I did not go any further with this in the previous week.

How ever, i have a NO switch as night/day switch - I can easily reverse it by a NOT gate. But that changes my night and day temp. selections as well.  (Night changes day temp and vice versa).

I can't see where excact the connection is, can you point me in the right direction?

EDIT: Day temp seems to work, and starting the heater. Night however does not start the heater, even if 25C is requested.

ixo65

I took the color white by day.

The error in the setpoint switching has resulted from your program change with the color markers.
You have not placed the NOT block on the control input S1 of the analog MUX, but on the EN input. As a result, the analog MUX has only been switched on and off.

Doh, what a bummer

I have set a max at 25 C, if a switch should get stuck (unlikely, but anyway)

Also the day program should be activated when I5 is high.

I think this should work. For translation: Dag = Day, Nat = Night

For rev. 6, i can't find the upper limits, nor the hysteresis adjustment.

Thanks, that makes sense..

I'll give, it's a lot cleaner that way.

So, just have to wire it up..

How much ventilation do I need to make in the box?

Finally my Siemens QAA2061 arrived - It's all up and running. It works like a charm.

I've played around, added a VFD output for fan control. Also some counters. (Haven't tested it yet)

Is it possible to automatic update the reset date on display 2?

Thanks,

I'll give it a try on the device, to see how it behaves.

Ohh I see..

Well, the LOGO! is online now, so i can do some experiments - Right now, i have a working program i can upload, if something fails.

If i get success, i'll of course upload the program. Might be useful for others to.

Got a little further in this.

Now there should appear a warning to order fuel when 400 hours is reached (set to 1 minute for simulation)

It's actually quite fun to play with this little device. I am overwhelmed by all those possibilities. Everyday i got a new idea, with a feature to add..

Maybe i should remove "final" from the filename I guess there will never be a final version. LOL

I'll still have to work with a timestamp, so i can see, when i last ordered fuel.

Hmmm...

It does not work.. The display will set an "error code", and tell me to order oil.

BUT, when the heater switches of, or i flip the night/day switch, it resets.

I tried a pulse triggered relay, and set the priority of B051 to 0 - What am i missing here?

Think I got it now..

0 is not highest priority, in my world it would be.. The LOGO! seems to have a different opinion..

I think it works now. Until I find another feature, that would be nice to have.

It will switch from red to amber diaplay, when night setting is on, but i can live with that. The message will appear, and that is most important..

Add'et a timer for daily start..

The temp is displayed as auto, but it is the day temp setting. I just wanna make sure no one alters the settings. There for the "Auto" (keep your fingers away) message.

It should run for some time, and if i don't switch on the day switch - Well, then there is no car on my lift, no work should be done, and it can go to night mode again. If there is something in the garage, then it will have preheated some time before i enter. Win win. :)

Will have to see, if it works tomorrow.

New question published by telegramteknik is split to a separate thread with the subject Want to use a PT1000 sensor, which parameters do have to change?.

Best regards
Jen_Moderator

Would you not be better off using different kit. For example if you used a process controller ( red lion for example ) and a suitable temperature probe you would be able to set point, upper limit and under limit control. Full functionality over the temperature. you could either use the relay output from the process controller  to control the heater or feed the output to your Logo for monitoring and switching of the heater. ? just a thought