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LOOP cycle problem

Created by: MX5_SVK at: 4/1/2013 6:37 PM (10 Replies)

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4/1/2013 6:37 PM	Rate (0)
MX5_SVK Posts: 4 Rating: (0)	Hello. I'm new in S7. I have one problem and I need a tip to solve it. I need to copy array of integer numbers in DB1 to another array with same attributes in DB2. I'm trying to do it with a LOOP cycle. But every time when I want to run program I'm getting this error: Area lenght error when writing. Global OB, byte access, Access address: 20 requested OB: programming error OB121 ..... My code LAR1 P#0.0 LAR2 P#0.0 L 9 S001: T #cyklus OPN DB 1 L DBB [AR1,P#0.0] OPN DB 2 T DBB [AR2,P#0.0] +AR1 P#2.0 +AR2 P#2.0 LOOP S001 DB1 and DB2are both adressed from DBW 0 to DBW 18 ( ARRAY[1..10] INT ). I really don't know what to do and why am I recieving this error. Can you help me please? I'm sorry for my poor english.
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4/1/2013 6:56 PM	Rate (1)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 10/26/2024 Posts: 6852 Rating: (1365)	MX5_SVK Hello. I'm new in S7. I have one problem and I need a tip to solve it. I need to copy array of integer numbers in DB1 to another array with same attributes in DB2. I'm trying to do it with a LOOP cycle. But every time when I want to run program I'm getting this error: Area lenght error when writing. Global OB, byte access, Access address: 20 requested OB: programming error OB121 ..... My code LAR1 P#0.0 LAR2 P#0.0 L 9 S001: T #cyklus OPN DB 1 L DBB [AR1,P#0.0] OPN DB 2 T DBB [AR2,P#0.0] +AR1 P#2.0 +AR2 P#2.0 LOOP S001 DB1 and DB2are both adressed from DBW 0 to DBW 18 ( ARRAY[1..10] INT ). I really don't know what to do and why am I recieving this error. Can you help me please? I'm sorry for my poor english. Hello, There are some points to clear before further discussion: 1-Why don't you use SFC20 for mass data transfer? 2-Why don't you load the loop counter at the end of codes in loop and before calling (LOOP S001 )? 3-Why don't you use method mentioned here to avoid opening DBs in loop? 4-If you use byte access and jump 2 bytes in each iteration, you may loose half of data width.I recommend WORD access as illustrated below. [code] LAR1 P#0.0 LAR2 P#0.0 OPN DB 1 OPN DI 2 L 9 lp: T #cyklus L DBW [AR1,P#0.0] T DIW [AR2,P#0.0] +AR1 P#2.0 +AR2 P#2.0 L #cyklus LOOP lp[/code] Best regards Hamid Hosseini
	Last edited by: hdhosseini at: 4/1/2013 7:29 PM // loop label is changed to be visible in code viewer Last edited by: hdhosseini at: 4/1/2013 7:09 PM Demo Channel on Youtube
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4/1/2013 7:06 PM	Rate (0)
yy1 Gold Member Joined: 3/24/2009 Last visit: 7/9/2024 Posts: 535 Rating: (112)	Dear MX5_SVK, as hdhosseini wrote, there are other ways to copy data from one DB to another. But if you want to use your code, you have to add one line of code: Your code: LAR1 P#0.0 LAR2 P#0.0 L 9 S001: T #cyklus OPN DB 1 L DBB [AR1,P#0.0] OPN DB 2 T DBB [AR2,P#0.0] +AR1 P#2.0 +AR2 P#2.0 L #cyklus // used by the loop-statement LOOP S001 Hope this helps! Best regards, yy1

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4/1/2013 7:11 PM	Rate (1)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 10/26/2024 Posts: 6852 Rating: (1365)	yy1 Dear MX5_SVK, as hdhosseini wrote, there are other ways to copy data from one DB to another. But if you want to use your code, you have to add one line of code: Your code: LAR1 P#0.0 LAR2 P#0.0 L 9 S001: T #cyklus OPN DB 1 L DBB [AR1,P#0.0] OPN DB 2 T DBB [AR2,P#0.0] +AR1 P#2.0 +AR2 P#2.0 L #cyklus // used by the loop-statement LOOP S001 Hope this helps! Best regards, yy1 what about the byte access(reading one byte) and jumping 2 bytes in each iteration?
	Last edited by: hdhosseini at: 4/1/2013 7:11 PM Demo Channel on Youtube
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4/1/2013 7:58 PM	Rate (0)
MX5_SVK Posts: 4 Rating: (0)	Thank you very much, code is working. But what about SFC20? I never used it before. You know im just learning about S7 and my only source of information is internet. So I have never heard about SFC20.
MX5_SVK Posts: 4 Rating: (0)
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4/1/2013 8:01 PM	Rate (1)
yy1 Gold Member Joined: 3/24/2009 Last visit: 7/9/2024 Posts: 535 Rating: (112)	hdhosseini what about the byte access(reading one byte) and jumping 2 bytes in each iteration? Absolut correct! Either L/T DBW [AR1/2,P#0.0] or +AR1 P#1.0 Find an example for the SFC20 here
	Last edited by: yy1 at: 4/1/2013 8:11 PM Last edited by: yy1 at: 4/1/2013 8:04 PM
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4/1/2013 8:05 PM	Rate (0)
MX5_SVK Posts: 4 Rating: (0)	thanks
MX5_SVK Posts: 4 Rating: (0)
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4/1/2013 8:12 PM	Rate (0)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 10/26/2024 Posts: 6852 Rating: (1365)	MX5_SVK Thank you very much, code is working. But what about SFC20? I never used it before. You know im just learning about S7 and my only source of information is internet. So I have never heard about SFC20. See the following as a more simpler equivalent: [code] CALL "BLKMOV" SRCBLK :=P#DB1.DBX 0.0 WORD 9 RET_VAL:=MW100 DSTBLK :=P#DB2.DBX 0.0 WORD 9[/code] You have option of using STEP7 online help for each block with some samples.For that select the block and press F1. Check the following clustered topics for SFC20: HD_Cases on SFC20 Best regards Hamid Hosseini Attachment sfc20.pdf (234 Downloads)
	Last edited by: hdhosseini at: 4/1/2013 8:16 PM // manual for SFC20 from STEP7 online help Demo Channel on Youtube
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4/1/2013 11:31 PM	Rate (0)
nbk Posts: 197 Rating: (3)	Hi hdhosseini/ yy1, I hope the following minor chages (in bold letters)would do the same function: LAR1 P#DBX.0 LAR2 P#DBX.0 L 9 S001: T #cyklus OPN DB 1 L B [AR1,P#0.0] OPN DB 2 T B [AR2,P#0.0] +AR1 P#1.0 +AR2 P#1.0 L #cyklus // used by the loop-statement LOOP S001 Regards
nbk Posts: 197 Rating: (3)
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4/2/2013 4:48 AM	Rate (0)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 10/26/2024 Posts: 6852 Rating: (1365)	nbk Hi hdhosseini/ yy1, I hope the following minor chages (in bold letters)would do the same function: LAR1 P#DBX.0 LAR2 P#DBX.0 L 9 S001: T #cyklus OPN DB 1 L B [AR1,P#0.0] OPN DB 2 T B [AR2,P#0.0] +AR1 P#1.0 +AR2 P#1.0 L #cyklus // used by the loop-statement LOOP S001 Regards Hello, if we do not care about the optimum and concise solution,there are some points to be corrected in your suggesting codes: 1-You are loading same value to AR1 and AR2, one seems to be enough and use AR1 instead of AR2 in your program. 2- "LAR1 P#DBX.0 " is a wrong notation for STL editor and you should try "LAR1 P#DBX0.0 " 3-Still there is a big problem with loop counter, accessing bytes and incrementing just one byte in pointer stored in AR1.9 WORDs consist of 18 bytes,so change the loop counter to 18.As your code suggests only half of the table in source area will be copied to the target area. LAR1 P#DBX 0.0 // LAR2 P#DBX 0.0 L 18 S001: T #cyklus OPN DB 1 L B [AR1,P#0.0] OPN DB 2 T B [AR1,P#0.0] +AR1 P#1.0 // +AR2 P#1.0 L #cyklus LOOP S001 Hope not to miss any major point! Best regards Hamid Hosseini
	Last edited by: hdhosseini at: 4/2/2013 4:52 AM // typo Demo Channel on Youtube
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