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gGet size of the array in DB

Created by: Goran_ at: 12/15/2010 10:31 AM (6 Replies)

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12/15/2010 10:31 AM	Rate (0)
Goran_ Posts: 141 Rating: (0)	How can I get the size of the array in data block? I want to be able to use the same function for different array size. Also, how do you write to static area of instance data block from FB? I need to write to array in static area. I will need to write to element based on its position (ex index = 3) Is there some documentatiom where I can read about this, I cannot find anywhere?
Goran_ Posts: 141 Rating: (0)
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12/15/2010 11:57 AM	Rate (0)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 6/6/2023 Posts: 6804 Rating: (1345)	Goran_ How can I get the size of the array in data block? I want to be able to use the same function for different array size. Despite string data types which includes 2 surplus bytes for maximum length and current length of the variable, for array as I checked the data structure , there is no extra space allocated for this purpose.Programmer before working with this data type should be aware of dimention of array and number of element used in it. Best regards
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12/15/2010 2:31 PM	Rate (0)
Goran_ Posts: 141 Rating: (0)	So there is no way to find the array size? What if I dont know the array size in advance? I want to prevent the code to try to write to non existing memory.
Goran_ Posts: 141 Rating: (0)
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12/16/2010 9:02 AM	Rate (0)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 6/6/2023 Posts: 6804 Rating: (1345)	Goran_ What if I dont know the array size in advance? I want to prevent the code to try to write to non existing memory. Check the attachment for defining the margins of 2 array defined in DB1.As you can see all margins are pre-determined due to variable definition. I hope this helps Best regards Attachment array.jpg (3510 Downloads)
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12/16/2010 9:10 AM	Rate (0)
Aret Posts: 2348 Rating: (259)	In SCL you can define size of some area: variable (complex or simple type), DB, etc. :^) /tf/WW/en/Posts/36944
Aret Posts: 2348 Rating: (259)
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12/16/2010 11:08 AM	Rate (1)
Chilly_Garfield Posts: 316 Rating: (37)	Hi Goran, in AWL an SCL you can get the length of a array, but you have to use pointer and have to know thestructur of pointer. The link from Aret is a good link, but I think a little bit confusing. My examples for a pointer access: SCL: VAR_TEMP A_Buffer_1: ANY;//dt: Anyzeiger auf den Datenbereich //eng: Anypointer on the data area A_Pointer_1 AT A_Buffer_1://dt: Pointersicht auf den Anyzeiger //eng: pointer vision on the anypointer STRUCT SyntaxID: BYTE; //dt: Hex fuer die Syntax-ID //eng: hex of the syntax-id DataType: BYTE; //dt: Hexwert fuer den Datentyp //eng: hexvalue of the data type DataCount: INT; //dt: Laenge des Bereiches //eng: length of the data area DB_Number: INT; //dt: DB-number / eng: DB number BytePointer: DWORD; //dt: Byte-und Bitadresse //eng: byte and bit address END_STRUCT; length:INT; END_VAR ... programm: A_Buffer_1:="DBx"."ARRAY"; CASE BYTE_TO_INT(A_Pointer_1.DataType) OF A_D_BYTE,A_D_CHAR : length:=A_Pointer_1.DataCount; //dt: keine Umrechnung / eng: no conversion A_D_WORD,A_D_INT,A_D_DATE,A_D_S5TIME : length:=2A_Pointer_1.DataCount; A_D_DWORD,A_D_DINT,A_D_REAL,A_D_TOD,A_D_TIME : length:=4A_Pointer_1.DataCount; A_D_DT : length:=8*A_Pointer_1.DataCount; A_D_STRING : A_Pointer_1.DataType:=B#16#02; A_Pointer_1.DataCount:=1; A_Pointer_1.BytePointer:=DINT_TO_DWORD(DWORD_TO_DINT(A_Pointer_1.BytePointer)+8); BLK_MOV:= BLKMOV(SRCBLK := A_Buffer_1 // IN: ANY ,DSTBLK := Value_1 // OUT: ANY ); // INT IF BLK_MOV >0 THEN "COMPARE_DATA":="COMPARE_DATA" OR BLKMOV_ERROR; END_IF; ELSE: //dt: Fehlerfall / eng: error case END_CASE; ========================================================================= AWL: VAR_TEMP: A_Buffer_1:ANY; A_Pointer_1://dt: Pointersicht auf den Anyzeiger //eng: pointer vision on the anypointer STRUCT SyntaxID: BYTE; //dt: Hex fuer die Syntax-ID //eng: hex of the syntax-id DataType: BYTE; //dt: Hexwert fuer den Datentyp //eng: hexvalue of the data type DataCount: INT; //dt: Laenge des Bereiches //eng: length of the data area DB_Number: INT; //dt: DB-number / eng: DB number BytePointer: DWORD; //dt: Byte-und Bitadresse //eng: byte and bit address END_STRUCT; END_VAR ...porgramm L P## "DBx"."ARRAY"; LAR1; //dt: Zeiger aus der Struktur zusammen bauen //eng: bulid the pointer with the structur from the output variable //============================================ LB[AR1,P#0.0]; Tpoint_vision.SyntaxID; LW[AR1,P#1.0]; Tpoint_vision.DataType; LW[AR1,P#2.0]; Tpoint_vision.DataCount; LW[AR1,P#4.0]; Tpoint_vision.DB_Number; LW[AR1,P#6.0]; Tpoint_vision.BytePointer; ... then you can work with the values like the SCL example.
Chilly_Garfield Posts: 316 Rating: (37)
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12/4/2017 2:21 AM	Rate (0)
igormf Advanced Member Joined: 10/7/2009 Last visit: 2/24/2023 Posts: 18 Rating: (1)	Chilly_Garfield Hi Goran, in AWL an SCL you can get the length of a array, but you have to use pointer and have to know thestructur of pointer. The link from Aret is a good link, but I think a little bit confusing. My examples for a pointer access: SCL: VAR_TEMP A_Buffer_1: ANY;//dt: Anyzeiger auf den Datenbereich //eng: Anypointer on the data area A_Pointer_1 AT A_Buffer_1://dt: Pointersicht auf den Anyzeiger //eng: pointer vision on the anypointer STRUCT SyntaxID: BYTE; //dt: Hex fuer die Syntax-ID //eng: hex of the syntax-id DataType: BYTE; //dt: Hexwert fuer den Datentyp //eng: hexvalue of the data type DataCount: INT; //dt: Laenge des Bereiches //eng: length of the data area DB_Number: INT; //dt: DB-number / eng: DB number BytePointer: DWORD; //dt: Byte-und Bitadresse //eng: byte and bit address END_STRUCT; length:INT; END_VAR ... programm: A_Buffer_1:="DBx"."ARRAY"; CASE BYTE_TO_INT(A_Pointer_1.DataType) OF A_D_BYTE,A_D_CHAR : length:=A_Pointer_1.DataCount; //dt: keine Umrechnung / eng: no conversion A_D_WORD,A_D_INT,A_D_DATE,A_D_S5TIME : length:=2A_Pointer_1.DataCount; A_D_DWORD,A_D_DINT,A_D_REAL,A_D_TOD,A_D_TIME : length:=4A_Pointer_1.DataCount; A_D_DT : length:=8*A_Pointer_1.DataCount; A_D_STRING : A_Pointer_1.DataType:=B#16#02; A_Pointer_1.DataCount:=1; A_Pointer_1.BytePointer:=DINT_TO_DWORD(DWORD_TO_DINT(A_Pointer_1.BytePointer)+8); BLK_MOV:= BLKMOV(SRCBLK := A_Buffer_1 // IN: ANY ,DSTBLK := Value_1 // OUT: ANY ); // INT IF BLK_MOV >0 THEN "COMPARE_DATA":="COMPARE_DATA" OR BLKMOV_ERROR; END_IF; ELSE: //dt: Fehlerfall / eng: error case END_CASE; ========================================================================= AWL: VAR_TEMP: A_Buffer_1:ANY; A_Pointer_1://dt: Pointersicht auf den Anyzeiger //eng: pointer vision on the anypointer STRUCT SyntaxID: BYTE; //dt: Hex fuer die Syntax-ID //eng: hex of the syntax-id DataType: BYTE; //dt: Hexwert fuer den Datentyp //eng: hexvalue of the data type DataCount: INT; //dt: Laenge des Bereiches //eng: length of the data area DB_Number: INT; //dt: DB-number / eng: DB number BytePointer: DWORD; //dt: Byte-und Bitadresse //eng: byte and bit address END_STRUCT; END_VAR ...porgramm L P## "DBx"."ARRAY"; LAR1; //dt: Zeiger aus der Struktur zusammen bauen //eng: bulid the pointer with the structur from the output variable //============================================ LB[AR1,P#0.0]; Tpoint_vision.SyntaxID; LW[AR1,P#1.0]; Tpoint_vision.DataType; LW[AR1,P#2.0]; Tpoint_vision.DataCount; LW[AR1,P#4.0]; Tpoint_vision.DB_Number; LW[AR1,P#6.0]; Tpoint_vision.BytePointer; ... then you can work with the values like the SCL example. Thanks for such an amazing answer! However, I can't seem to find a way to complete the "A_D_STRING" case, after the block move how to check for the string's size? Thank you again

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