Pragma for nonpersistent data types, L-force | plc designer – Lenze PLC Designer PLC Designer (R2-x) User Manual

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L-force | PLC Designer

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DMS 3.2 EN 02/2011 TD29

281

7.3.6

Pragma for nonpersistent data types

Normally the following is valid: Even if only one local variable in a function block or a
structure is declared persistent, at usage of an instance automatically all components
will be stored in the persistent information (persist.dat) on the runtime system. In
order to save space you can use the pragma

{nonpersistent}

in the declaration of the function block resp. the structure. It effects that

only

those

components of the function block resp. structure, which are declared as "persistent",
will be entered to the persistent info.

Example:

If an instance of the following function block is declared as persistent, only variables
local and fblevel3 will be written to the persistent info. Without pragma
{nonpersistent} all function block variables would be stored there.

FUNCTION_BLOCK FB_Level_2

{nonpersistent}

VAR_INPUT

bvar_in : BOOL;

END_VAR

VAR_OUTPUT

bvar_out : BOOL;

END_VAR

VAR

ivar2 : INT;

END_VAR

VAR PERSISTENT

local : INT := 33;

fblevel3 : FB_Level_3;

END_VAR

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