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S7-1200 - Indirect Addressing

Created by: Navnag at: 6/30/2013 5:03 PM (9 Replies)

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6/30/2013 5:03 PM	Rate (0)
Navnag Platinum Member Joined: 11/21/2007 Last visit: 1/11/2021 Posts: 2320 Rating: (298)	Hello Experts I am using S7-1200 for the first time in a project. I would like to know, how to implement indirect addressing ( Pointers ) in S7-1200 In particular i want to know hoe to copy one Memory area to another, e.g. how to copy part/whole of One Data block to another. ( Something like BLOCKMOV ( SFC20 ) of S&-300 or @pointer of S7-200 Thanks Navnag
	Last edited by: Navnag at: 6/30/2013 5:47 PM Subject corrected There is no such thing as the last bug in a program There are no stubborn bugs, There are only stubborn Debuggers.
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6/30/2013 5:35 PM	Rate (0)
BryanG2001 Bronze Member Joined: 4/20/2011 Last visit: 11/11/2018 Posts: 113 Rating: (21)	/tf/WW/en/Posts/90691 You need to switch to SCL programming. If working with DBs, the DB mustn't be set for Optimised access.

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6/30/2013 5:50 PM	Rate (0)
Navnag Platinum Member Joined: 11/21/2007 Last visit: 1/11/2021 Posts: 2320 Rating: (298)	Thanks BryanG2001 Will definitely try this !! However would have preffered a simpler implementation in LAD / STL Cheers Navnag
	There is no such thing as the last bug in a program There are no stubborn bugs, There are only stubborn Debuggers.
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6/30/2013 7:07 PM	Rate (1)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 1/21/2021 Posts: 6707 Rating: (1286)	Navnag Thanks BryanG2001 Will definitely try this !! However would have preffered a simpler implementation in LAD / STL Cheers Navnag if you want an option to copy from a source to a target you can test MOVE_BLK (Like SFC 20 IN S7 300/400) UMOVE_BLK(Like SFC 81 IN S7 300/400) They can be used in LAD and FBD.Inputs are an array plus nuber of components and the output where the data should be copied.For exact description consult the manual.For S7 1200,STL is not supported.
	Last edited by: hdhosseini at: 6/30/2013 7:07 PM Demo Channel on Youtube
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6/30/2013 9:06 PM	Rate (1)
BryanG2001 Bronze Member Joined: 4/20/2011 Last visit: 11/11/2018 Posts: 113 Rating: (21)	However would have preffered a simpler implementation in LAD / STL That makes two of us. STL should be do-able but is outside my experience. Unless you use Arrays as suggested by hdhosseini there is currently nothing in LAD. I very much miss the simplicity of something like '#Joint_start_point:LD0' in MicroWin, though I shouldn't complain, it is only recently that the easy but large method of POKE_BLK has become available.

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7/1/2013 8:22 AM	Rate (1)
Navnag Platinum Member Joined: 11/21/2007 Last visit: 1/11/2021 Posts: 2320 Rating: (298)	Thanks hdhosseini I am using MOVE_BLK already, however it is able to move only one array. My Data Blocks contain Multiple arrays so I need to use MOVE_BLK for each array . This is not the same SFC 20 of S7-300/400 POKE_BLK instruction of SCL seems to be promising. Although I am not very comfortable with SCL as of now but have started working using this instruction. SAD .. Siemens killed STL in S7-1200 .. my favourite an dmost flexible programming language ... Cheers Navnag
	Last edited by: Navnag at: 7/1/2013 8:50 AM Last edited by: Navnag at: 7/1/2013 8:30 AM There is no such thing as the last bug in a program There are no stubborn bugs, There are only stubborn Debuggers.
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7/1/2013 1:15 PM	Rate (0)
BryanG2001 Bronze Member Joined: 4/20/2011 Last visit: 11/11/2018 Posts: 113 Rating: (21)	I haven't programmed in machine code for 30 odd years, not since I got my first computer and the Basic Interpreter Eeprom chip wasn't yet available, I must say that I don't miss it. However STL isn't dead, there are references to it in the help section and settings in the Options bit. You are supposed to be able to import STL code using 'External source files' but that only give an import filter for SCL. Hopefully (well hopefully for you) it will make a proper reappearance in a future TIA update. You may find that SCL will do a lot of what you want, it is more like a high level computer language than PLC software, it is very similar to an old version of Pascal. If you do a search here there are pointers to Siemens manuals listing SCL functions.

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7/2/2013 3:00 PM	Rate (1)
ramiv Experienced Member Joined: 5/7/2007 Last visit: 1/14/2019 Posts: 55 Rating: (1)	You should rethink your project and structures, and then you can do things that were not possible in the past. I had used a lot of pointers in the past, but with TIA and 1200 you can do things nicely in other ways. I have made a data type, called "Schedule_type" which contains all variables needed for an certain recipe, booleans, bytes and so on, and after this i create an DB (DB2) with name "Programs" which has a variable line defined: 'Schedules' as Array [1..10] of "Schedule_Type", and voila, now i can do this kind of things in the code : #DataOut:= "Programs".Schedules[#Index]; Where #Index is another variable, and #DataOut is in this case an output-type variable in an FC block. This line copies the whole content of n-th element in the Schedules[] structure into the #DataOut-variable. Now if i have to add another bit for example into the Schedule_type, i only need to recompile the DB-s, but no need to change the code to copy this bit too. So you need to arrange your data structures right, and think differently than in the past. There are other things in TIA which are not so nice, but this one really is good.

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7/2/2013 3:25 PM	Rate (0)
Navnag Platinum Member Joined: 11/21/2007 Last visit: 1/11/2021 Posts: 2320 Rating: (298)	Hello ramiv Fully agree with you that there are many good things ( and a few winderful things ) in TIA ... however it always would make sense to carry forward good features of existing systems while adding new ones. Would definitely like to explore your suggestion. Cheers Navnag
	There is no such thing as the last bug in a program There are no stubborn bugs, There are only stubborn Debuggers.
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3/31/2014 3:39 PM	Rate (0)
CS Moderator Moderator Joined: 9/1/2005 Last visit: 1/21/2021 Posts: 3947 Rating: (187)	follow up question published by laantjeis split to a sperate thread with the subject S7-1200 - Indirect Addressing of data within a DB. Best reagards CS Moderator

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