Hi

to copy data from one DB to another or from one area od DB to another area of the same DB you can use the below:

FUNCTION "DBDB_COPY" : VOID
TITLE =Copy data between two DBs
//Copies data from source to target.
VERSION : 0.0


VAR_INPUT
I_ARG1_DB : INT ;    //Argument 1 DB Number
I_ARG1_START : DINT ;    //Argument 1 Start Address
I_ARG2_DB : INT ;    //Argument 2 DB Number
I_ARG2_START : DINT ;    //Argument 2 Start Address
I_LENGTH : INT ;    //Length of arfea to be compared
END_VAR
VAR_TEMP
SaveAR1 : DWORD ;    //Buffer for address registers
Address1 : DWORD ;    //Address 1 - Source
Address2 : DWORD ;    //Address 2 - Source
L_Cntr : INT ;    //Loop Counter
Arg1DBNo : INT ;    //Argument 1 DB Number
Arg2DBNo : INT ;    //Argument 2 DB Number
Buffer : BYTE ;    //Buffer for Copying
END_VAR
BEGIN
NETWORK
TITLE =Save existing value from address register
//Saves values from AR1 - it will be restored when FC is complete
TAR1  ;
T     #SaveAR1;
NETWORK
TITLE =Initialize Address Registers and Data Block Numbers
//Initialization of address registers.
L     P#DBX 0.0; // Pointer
L     #I_ARG1_START; // To beginning of Area 1
SLD   3;
+D    ;
T     #Address1; // To Address Register 1

L     #I_ARG1_DB; // Temp value must be used in OPN DB [#xxx]
T     #Arg1DBNo; // so input is copied to Temp

L     P#DBX 0.0; // Pointer
L     #I_ARG2_START; // To beginning of Area 2
SLD   3;
+D    ;
T     #Address2; // To Address Register 2

L     #I_ARG2_DB; // Temp must be used for OPN DB [#...]
T     #Arg2DBNo; // so input is copied to Temp
NETWORK
TITLE =Copy Loop

L     #I_LENGTH; // Length of area to be compared
NEXT: T     #L_Cntr; // from second pass LOOP instruction updates counter

OPN   DB [#Arg1DBNo]; // Open Argument 1 DB

LAR1  #Address1;
L     DBB [AR1,P#0.0]; // Load Value from memory area
T     #Buffer;

+AR1  P#1.0; // Update Source Address
TAR1  #Address1;

OPN   DB [#Arg2DBNo]; // Open Argument 2 DB
LAR1  #Address2;

L     #Buffer;
T     DBB [AR1,P#0.0]; // Transfer to target

+AR1  P#1.0; // Update Destination Address
TAR1  #Address2;

L     #L_Cntr; // Load Loop Counter
LOOP  NEXT; // If loop not finish jump to Next

LAR1  #SaveAR1; // Restore Address Registers

SET   ; // ENO is always true
SAVE  ;
END_FUNCTION

if you use multiple instance calls AR2 is used for these.

you need restore AR2 after using it.

you need

at the beginning - backup ARs

TAR1  #Kopia_AR1
TAR2  #Kopia_AR2

at the end - restore ARs

LAR1  #Kopia_AR1
LAR2  #Kopia_AR2

AR2 is used by the system for multiple instance calls

Loops - if you loop to process next recipe remember to OPN data blick again after
T     "TrawersePosDB".ActualRecipe

because the above instruction implicitly opens "TrawersePosDB" to perform operation

Hi

attached project - it contains recipe handling block

functionality

database - recipe database (all recipes)

used - one currently used for production

displayed - one displayed on hmi for selection or edit

covers activation of recipe (copy database-->activated), undo edit (database-->displayed), undelete/delete/save and navigation i.e. show first / prev / next and option to show/skip empty (deleted) records.c

Hi

I do save/restore AR registers just in case they are used by other interrupts blocks et:

Save AR1
Do your processing
Restore AR1 to its previous value

same for AR2 if used.

FBs - AR2 is used by the system itself and when altered for example multiple instance calls will not work

Temp variables - these are valid for current scan only and consider them lost as soon as block processing is finished. do not use Temp for counters and any other things where value from previous scan is needed - and always ensure Temp variables are written to before being read.
Example

#A is declared as Temp

Nw1:
L #A // WRONG!!! - #A is UNDEFINED - can have a random value in it.
(...) code

(...)

NW2:
(...)code
T #A

NW3:

L #A // here #A has value written in NW2

Icos13

Any advices  ? 

No time to open up your project, so only general advice.

Once you alter AR2 all symbolic accesses to IN/OUT/IN_OUT/STAT became invalid. Therefore if you plan to use it:

• store AR2 content
• change it
• do whatever you need to do WITHOUT using any symbolic access as mentioned above
• restore AR2 content
• symbolic access is valid again

Oh, yeah, as mentioned symbolic accesses become invalid it is clear that AR2 must be stored in TEMP variable if symbolic access is used, right?