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S7-1200 High level instructions (IF THEN, WHILE, FOR NEXT) in ladder language

Created by: Denilson Pegaia at: 5/4/2011 3:05 PM (10 Replies)

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5/4/2011 3:05 PM	Rate (5)
Denilson Pegaia Platinum Expert Joined: 9/23/2005 Last visit: 1/17/2021 Posts: 3882 Rating: (1148)	We havesomecustomersthat contact me and relates the necessity to convert one high level language software to a S7-1200 (ladder). They have difficult to convert simple instructions like IF THEN, FOR NEXT, WHILE, etc in ladder. In this context, the normal way were wait to SCL will be avaliable to S7-1200 (maybe ~~V11 SP1~~ V11SP2), however in this mean time, as result of these consults,I build a sample program with examples of how to use ladder instructions (e.g. LABELS, JMP, comparators, etc.) could be used to perform these high level instructions. Thinking that this example could be useful to others customers I post here these sample program. Attachment IF THEN.zip (939 Downloads)
	Last edited by: Pegaia at: 10/31/2011 10:09 AM Denilson Pegaia Siemens Industry Sector Technical Support
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This contribution was helpful to 13 thankful Users luciferC4 UMENCHO XANTA! Marcjan MrPaiva 0_Einstein amcorgd AmirAlwaled FAR_EAST GaJEnDrA D S ASINPRO SA vasbouga Arasan

5/4/2011 5:59 PM	Rate (0)
UMENCHO Diamond Member Joined: 3/21/2006 Last visit: 1/7/2021 Posts: 10217 Rating: (1158)	Pegaia ...Thinking that this example could be useful to others customers I post here these sample program. For sure will be. All examples are useful in the right moment. As I like to say - Keep Walking! Best regards, Hristo Mihalev

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6/15/2011 1:57 PM	Rate (0)
AmirAlwaled Bronze Member Joined: 9/28/2010 Last visit: 12/2/2020 Posts: 148 Rating: (13)	I don't have STEP 7 for 1200 so could you upload pic's or pdf's or printed files

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6/15/2011 6:51 PM	Rate (1)
Denilson Pegaia Platinum Expert Joined: 9/23/2005 Last visit: 1/17/2021 Posts: 3882 Rating: (1148)	Hi, here there is it Attachment document.zip (863 Downloads)
	Denilson Pegaia Siemens Industry Sector Technical Support
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This contribution was helpful to 3 thankful Users AmirAlwaled janneia Arasan

6/15/2011 7:27 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/16/2021 Posts: 9948 Rating: (1653)	Would be good to add some documentation in the ladder logic to indicate approx how many loops before it kicks out for default watchdog time fault of ~150 ms. If scan time for the loop is 1 ms, and overall scan time is 15 ms, you get around 130 loops before it fails on watchdog fault. Perhaps there is a way to handle larger looping needs that run outside the main loop a little at a time so it doesn't hurt overall processing too much. Do you have examples of looping around 1000 times, like for calculating an integral for an input signal over a second or more? It's a long loop, but not best handled by any of the techniques covered in the high level instructions. I'd suggest teaching people how to do something one scan at a time until the 'loop' is complete, then set a done bit to read or save the value. That to me is more valuable because it works with the scan and allows the PLC to continue processing. Each technique has its place, but can be misleading for people unfamiliar with how PLCs scan inputs, process logic, and set outputs, and repeat that process. If in the process logic we add looping structures, it is very easy to fault a PLC on watchdog fault, especially if no bounds are set for loop counters. Just another thought on the matter.
	science guy
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6/15/2011 10:26 PM	Rate (0)
Denilson Pegaia Platinum Expert Joined: 9/23/2005 Last visit: 1/17/2021 Posts: 3882 Rating: (1148)	Hi, the execution time depends of the hardware. It is difficult to put in a table, because there many types of CPU (in special, if you take in account that WinAC can run in several differents PC's). On other hand, the watchdog could be configured up to ~6.5seconds. The main objective here is just to show the simplest structures in ladder, however the Ideia to split the loop over several OB cicle is nice.Maybe someone could place here other examples.
	Denilson Pegaia Siemens Industry Sector Technical Support
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10/29/2011 5:17 AM	Rate (0)
GaJEnDrA D S Bronze Member Joined: 8/9/2011 Last visit: 1/11/2021 Posts: 298 Rating: (18)	Hi Can you put the same file conveted into V11 as i dont have V10.5 In addition there is no converter tool in V11 but in V10.5... Thank you
	"Any intelligent fool can make things bigger, more complex. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction.":):)
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10/31/2011 10:10 AM	Rate (0)
Denilson Pegaia Platinum Expert Joined: 9/23/2005 Last visit: 1/17/2021 Posts: 3882 Rating: (1148)	Hi, normally, you can open a V10.5 with V11. The software as you if it could convert the project, and make the convertion. Did you have problems to convert it?
	Denilson Pegaia Siemens Industry Sector Technical Support
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5/29/2013 11:32 AM	Rate (0)
GaJEnDrA D S Bronze Member Joined: 8/9/2011 Last visit: 1/11/2021 Posts: 298 Rating: (18)	No. I could open it
	"Any intelligent fool can make things bigger, more complex. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction.":):)
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5/29/2013 12:51 PM	Rate (1)
Denilson Pegaia Platinum Expert Joined: 9/23/2005 Last visit: 1/17/2021 Posts: 3882 Rating: (1148)	Hi, anyway here there is a V11SP2upd5 version Attachment IF THEN_V11 SP2 Update 5.zip (242 Downloads)
	Last edited by: O_Moderator at: 5/29/2013 12:58 PM Denilson Pegaia Siemens Industry Sector Technical Support
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This contribution was helpful to 1 thankful Users GaJEnDrA D S

4/16/2016 12:43 PM
EIC_CONTROL Bronze Member Joined: 4/2/2013 Last visit: 4/17/2020 Posts: 198 Rating: (35)	zip file for tia portal v10.5 I think I can not open it in tia portal v13
	HOPE THIS HELPFULL
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