Novice ask to help with cooling system

Good evening, 

I am lookig for help with my Logo! 8 test. I have Logo with AM2 RTD and PT100. Now I dont know how make my program.

I would like to make a cooling system for my little greenhouse. My plane: just set ONE required temperature (example 29°C) and when raise PT100 29 - open Q. When temp. decrease to 28 - close Q. But I want to set just one  value (no open 29 and close 28) -> its possible? (in attachment its for me bad program - must set start and stop)

Second question: Its possible to set maximum and minimum value temp? I mean, I would like to try make heating (on winter) and if I set heating on 24°C I would like to if possible set cooling no lower than xx (for example heating start set 20°C Stop 30°C and heating minimum temp. must be more than this 30°C)

Third question: Can I swap controll my menu with logo menu? I want scrolling my menu via arrow without holding ESC button. Just push arrow button will scroll my menu, hold ESC and push arrow will scroll logo menu.

At last, I would like to say sorry for my english, Iam start learning 6 months ago... 

Here is a suggestion on my part.

You can adjust the desired values for on / off over the display.

If you have created your own menu with message texts, you can only scroll with the combination of ESC + Cursor. This is not changeable.

Thank you for your reply.

About this ON/OFF on display I know. But I want just one value for change - of course, only if its possible. 

This menu is sad :( 

I don't understand what you want exactly.
Please describe precisely your problem.

What do you mean with: 

Chlebik

But I want just one value for change - of course, only if its possible

 
For example, to change only the ON value and the OFF value automatically adjusts? With always the same difference?

PS: What do you already know and what you do not know, that I can't know.

Great work! This is exactly what Iam looking for! Thank you!

Could you tell me, how you can add B004 to V1? This maybe solve my second problem with minimum value.

One more thank you!

At first, thank you for your positive Feedback and your good rating.

In the message text B003 I refer to B004, parameter V1. B004 then refers to the output Aq on B001, parameter ON and B005, parameter V1. In B005 I prefer 1.0 ° C (10 units) from and refer to the output of Aq B005 to B001, parameter OFF.

Chlebik

Thank you for your time and explain! Nothing to stop me now, I can plant my herbs without nightmares :)

Hello Chlebik,

you're welcome.

And I wish no more nightmares....

Ok, I am BACK, like a Terminator T-X wihout boobs.

I hope, my last question for long time - Do you know some wind speed senzor with analog ouput 0 - 10V or something else for use with logo? What is better for this - 0-10V or 4-20mA? Average quality, price approx. 100US without wind direction.

What is better for this - 0-10V or 4-20mA?

Some LOGO!s have a analog input 0-10 Volt, so if you have a 0-10V sensor, you can directly connect it to your LOGO.

An 4-20mA sensor is compared with a 0-10V signal a more robust sensor which is less affected by interference influences. Therefore less failures. Often two wire so aansluitingenetc cheaper.

But u have to use an aditional unit to the LOGO (an extensionunit) for connecting the 4-20 mA signal to the LOGO

You can also use a 500 Ohm resistor to make a 2-10V signal of the 4-20mA signal. That 2-10 Volt signal can also direct connect to a LOGO with an analog Input 0f 0-10Volt. The difference 0-10V od 2-10V is not important, you can adjust this in the software of LOGO