VAR, PERS,and CONST

carmila · June 2009

Dear all,

I've been informed that PERS data can be stored unless the controller is shut down, but, in my case, the data using PERS is gone after I turn off the controller. Can anyone know what is the conclusions to make data is kept store unless the controller is shutdown, even if I load a new program?

Thank you

BR,

Lin · June 2009

Try to create your variable, pers, const in different module.

and ensure that before starting new program. r u saving the current program properly.

If any errors, please try to save each module separately.

carmila · June 2009

Dear Lin,

OK, I will try it. So, when I restore my system, I only load the module that contain my datas. Is it right?

BR,

Klaus · June 2009

Hi Carmila.

Have you init your PERS with a Value?

PERS Num Name:=0;

BR Klaus

carmila · June 2009

Dear Klaus,

I only write:

PERS num name;

only that. Is any differences with and without a value ( PERS num name : 0)?

Thank you

BR,

carmila · June 2009

Dear Klaus,

I only write:

PERS num name;

only that. Is there any differences with / without a value? ( PERS num name :=0)

Thank you

BR,

charon · June 2009

Hi Carmila,

Persistent variables must have an initial value. When u change ur variable value, initialisation value of that persistent updated. So when u load module again controller creates persistent with last initialisation value and that keeps it unchanged.

Klaus · June 2009

Hi Camaile.

That's why it don't work. PERS without init value will do the same as a VAR and not remember the value. Even PP to main will delete the value

BR Klaus

carmila · June 2009

Dear Klaus and Charon,

Thank you for your information.A? Smile

I will change it.A?

BR,

VAR, PERS,and CONST

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