Hello all

I m new here and in LOGO! and I guess this is the first time i m writing here. I would like to help me in a project I have to accomplished.

I have 8 switches for 7 loads (each load have its own on/off switch (not button), the 8th is for automatic mode)

I need this function :

A) If 1 or 2 switches (for example I1 and I2, or I1 and I7, or I4 and I6 etc are ON then disable all the rest. In fact I need only 2 loads (from the 7) to be ON every time

B) The I8 switch I need to turn on automatic mode with a timer so : a) to disable all inputs (whatever states they are)  and  go this way :  Q1 and Q2 on for 20 min, then Q3 and Q4 ON for 20 min, then Q5 and Q6 for 20min and then Q7 for 20 min.

Since i m very new to LOGO, please can you also tell me which LOGO modules I need ?  I prefer everything work with 230V. 

No need to make for me all the circuit just some examples. Also is it easier to do it with buttons instead of switches ?

I would appreciate any help

Thank you

Thank you for the fast response !!!

Let me explain better :

We have 7 electrical boilers (lets name them Q1,Q2, ...Q7) for 7 room spaces

Each one have a switch in order to be ON or OFF (so we have 7 inputs) manually. But only  2 boilers can operate at the same time (simultaneously)  due to low central power supply.

If user need to set for example Q1 (ON) and Q2 (ON), then the rest boilers should not be allowed to operate (be OFF) regardless if another user tries to switch on Q4 for example.

or If user need to set for example Q2 (ON) and Q6(ON), then the rest boilers should not be allowed to operate (OFF) and so on. 

Every time, only 2 boilers max can operate simultaneously (the first 2 user set ON). 

There is also a 8th switch that is intended for automatic operation like this :

If switch 8 is ON, then predetermined pairs of boilers will operate automatic for time X (minutes) like this : 

Q1 and Q2 for time X

after time X pass, Q1 and Q2  goes OFF and

Q3 and Q4 set ON for time X and so on for

Q5 and Q6 for time X

Q7 for time X

and again from the start (cyclical operation) as long as I8 (switch 8) in ON

no manual control allowed when switch 8 (automatic) is ON.

Hope this description be better

Thank you

Thank you so much

let me check the file and see what I can understand