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Arrays, DB and pointers

Created by: edsan at: 4/5/2013 2:19 AM (6 Replies)

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4/5/2013 2:19 AM	Rate (0)
edsan Posts: 31 Rating: (0)	Hi everybody. PLEASE! Could anyone help me with this? FIRST I have a array of 20x30 INT elements ( this array is declared inside of a DB in Step7 ). I need to read / write values using indirect addressing like DB1."MATRIX"[MD10 , MD20] by example... (or absolut mode db1.dbd2 bla bla bla )... Where MD10 and MD20 are numbers that I can change during the machine cycle. Is it possible? SECOND Another doubt: in place of MD20 from syntax above can I use a pointer P# ? Since now thanks a lot!!! Best regards, edsan
edsan Posts: 31 Rating: (0)
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4/5/2013 5:01 AM	Rate (1)
playerslight Posts: 1064 Rating: (72)	Helllo edsan Take a look at this link it should help you with the pointers pay attention to ibn services reply /tf/WW/en/Posts/73282
playerslight Posts: 1064 Rating: (72)
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This contribution was helpful to 1 thankful Users edsan

4/7/2013 1:20 PM	Rate (1)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 9/7/2024 Posts: 6846 Rating: (1365)	edsan Hi everybody. PLEASE! Could anyone help me with this? FIRST I have a array of 20x30 INT elements ( this array is declared inside of a DB in Step7 ). I need to read / write values using indirect addressing like DB1."MATRIX"[MD10 , MD20] by example... (or absolut mode db1.dbd2 bla bla bla )... Where MD10 and MD20 are numbers that I can change during the machine cycle. Is it possible? SECOND Another doubt: in place of MD20 from syntax above can I use a pointer P# ? Since now thanks a lot!!! Best regards, edsan Hello, Solving a case like that by STL may include such complexity that makes it difficult to trace.For your case that is a type of data management, I suggest using SCL which is more efficient for those cases.See the following SCL source code in combination with the attachment. The outcome is interesting. [code]ORGANIZATION_BLOCK OB1 author:hdh VAR_TEMP // Reserved info : ARRAY[0..19] OF BYTE; // Temporary Variables i:INT; j:INT; END_VAR // Statement FOR i:= 1 TO 10 BY 1 DO // Statement Section FOR j:= 1 TO 10 BY 1 DO test.hd[i,j]:=i*j; ; END_FOR; ; END_FOR; ; END_ORGANIZATION_BLOCK[/code] Best regards Hamid Hosseini Attachment 1.jpg (1673 Downloads)
	Demo Channel on Youtube
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4/7/2013 3:20 PM	Rate (1)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 9/7/2024 Posts: 6846 Rating: (1365)	Hello, And this is the STL version,To manipulate a cell in STL, You should know the absolute address(offset) in corresponding DB. As a demo solution provided in SCL ,Check the noticeable differences. [code]ORGANIZATION_BLOCK "Cycle Execution" TITLE = "Main Program Sweep (Cycle)" AUTHOR : HD FAMILY : Forum_E NAME : Demo1 VERSION : 0.1 VAR_TEMP OB1_EV_CLASS : BYTE ; //Bits 0-3 = 1 (Coming event), Bits 4-7 = 1 (Event class 1) OB1_SCAN_1 : BYTE ; //1 (Cold restart scan 1 of OB 1), 3 (Scan 2-n of OB 1) OB1_PRIORITY : BYTE ; //Priority of OB Execution OB1_OB_NUMBR : BYTE ; //1 (Organization block 1, OB1) OB1_RESERVED_1 : BYTE ; //Reserved for system OB1_RESERVED_2 : BYTE ; //Reserved for system OB1_PREV_CYCLE : INT ; //Cycle time of previous OB1 scan (milliseconds) OB1_MIN_CYCLE : INT ; //Minimum cycle time of OB1 (milliseconds) OB1_MAX_CYCLE : INT ; //Maximum cycle time of OB1 (milliseconds) OB1_DATE_TIME : DATE_AND_TIME ; //Date and time OB1 started int_lp_counter : INT ; ext_lp_counter : INT ; buffer1 : DINT ; END_VAR BEGIN NETWORK TITLE = OPN "test"; //open related db1 /////////////////EXTERNAL LOOP/////////// L 10; lp1: T #ext_lp_counter; //calculate pointer to access corresponding i,j cell //1st section ITD ; L L#1; -D ; L L#20; // 2bytes for 10 cells D ; T #buffer1; ///////////////////INTERNAL LOOP//////// L 10; lp2: T #int_lp_counter; //calculate pointer to access corresponding i,j cell //2nd section ITD ; L L#1; -D ; L L#2; D ; L #buffer1; +D ; SLD 3; L P#DBX 0.0; OD ; LAR1 ; //final pointer formation L #int_lp_counter; L #ext_lp_counter; *I ; T W [AR1,P#0.0]; L #int_lp_counter; LOOP lp2; ///////////////////////////////////////////////////// L #ext_lp_counter; LOOP lp1; END_ORGANIZATION_BLOCK[/code] Feel free to improve or expand this draft Best regards Hamid Hosseini Attachment indirect_addressing.zip (1036 Downloads)
	Last edited by: hdhosseini at: 4/7/2013 3:26 PM // typo Last edited by: hdhosseini at: 8/2/2018 10:18:07 AM Demo Channel on Youtube
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4/10/2013 7:01 PM	Rate (0)
edsan Posts: 31 Rating: (0)	Thanks a lot for all !!!! We solve the problem with your help... Thanks hdhosseini and playerslight!!! Best regards! edsan
edsan Posts: 31 Rating: (0)
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This contribution was helpful to 1 thankful Users hdhosseini

12/24/2017 2:58 PM	Rate (0)
Masoud_Ra Posts: 12 Rating: (2)	Hello Hamid Hosseini where did you bring test from? you define info:ARRAY and didnt used it hdhosseini edsan Hi everybody. PLEASE! Could anyone help me with this? FIRST I have a array of 20x30 INT elements ( this array is declared inside of a DB in Step7 ). I need to read / write values using indirect addressing like DB1."MATRIX"[MD10 , MD20] by example... (or absolut mode db1.dbd2 bla bla bla )... Where MD10 and MD20 are numbers that I can change during the machine cycle. Is it possible? SECOND Another doubt: in place of MD20 from syntax above can I use a pointer P# ? Since now thanks a lot!!! Best regards, edsan Hello, Solving a case like that by STL may include such complexity that makes it difficult to trace.For your case that is a type of data management, I suggest using SCL which is more efficient for those cases.See the following SCL source code in combination with the attachment. The outcome is interesting. [code]ORGANIZATION_BLOCK OB1 author:hdh VAR_TEMP // Reserved info : ARRAY[0..19] OF BYTE; // Temporary Variables i:INT; j:INT; END_VAR // Statement FOR i:= 1 TO 10 BY 1 DO // Statement Section FOR j:= 1 TO 10 BY 1 DO test.hd[i,j]:=i*j; ; END_FOR; ; END_FOR; ; END_ORGANIZATION_BLOCK[/code] Best regards Hamid Hosseini
Masoud_Ra Posts: 12 Rating: (2)
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11/22/2018 1:49 PM	Rate (0)
jacek d Platinum Expert Joined: 9/23/2005 Last visit: 9/6/2024 Posts: 4686 Rating: (720)	Better late than never... People say. The code is for an OB block. Each OB, when started, is passed 20 bytes of so-called startup info which is OB type dependent. So, this array is a placeholder for this start-up info.
	Regards, Jacek What is confusing you is the fact that you never see a number but always its digit representation. So you end up thinking that the number is the representation. - Andrej Bauer Any claims against me - based on whatever legal reason - resulting from the use of any code and/or ideas presented on this forum shall be excluded. #StayWithUkraine
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