Hi everyone, recently purchased a Logo 8 latest model.

Let me briefly explain the PLC process so we all have a brief understanding on my operation requirements.

I am using the Logo for various timing functions, including pre-purge timers and cool down timers for an industrial oven, and we usually use external timers for these so i thought i will save some time wiring and i can use a logo 8!

Firstly, I am using a timing delay for a pre-purge (extract solvents out of the oven before the burner fires) this is set at 30 seconds and then upon timing down energises Q1. this is working perfectly

My next output will be a cool down so when i press "Stop" on my control panel
my voltage pulses "I2" and upon the timer counting (from 10 minutes) cuts the voltage on "Q2"  this is then the end of cycle - this is what i need!

However due to "Q2" not being normally closed, i am unable to achieve this requirement.
I would rather not start incorporating an external relay if i can help it.

Any suggestions?

P.S: LOGO 8 is 230v newest model i think

Best regards,
Shane

Thanks for your quick response. I appreciate the help.
Will try run that code and see how i get on

Many thanks 

Shane 

Good afternoon

Please can you advise where I can find the "not-block" function per your diagram?

Many thanks

Shane

Hi Ixo65

I am still progressing with my requirements on this unit and have achieved so.
Would you be able to explain how i would have a live input to "I4" to cut the supply at "Q2"

best regards 

Shane 

There are 8 inputs and 4 outputs on a logo 8.

I1 I2 I3 I4 I5 I6 I7 I8 

Q1    Q2    Q3    Q4

How do i program the logo so when i have an input on say for example I7
it breaks the circuit at Q2?

Regards 

Shane