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Week number in PLC

Created by: StanleyN at: 1/15/2009 11:06 AM (8 Replies)

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1/15/2009 11:06 AM	Rate (0)
StanleyN Posts: 5 Rating: (0)	Dear Experts, does enybody idea how to get "week number" in PLC? I know that are many different systems how to define first week of the year, but in Europe is typical used: (the week with the year's first Thursday in it (the ISO 8601 definition)). http://en.wikipedia.org/wiki/ISO_week_date I need to print this number on customers product. best regards Stanislav Novotný
StanleyN Posts: 5 Rating: (0)
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1/15/2009 12:01 PM	Rate (0)
UMENCHO Diamond Member Joined: 3/21/2006 Last visit: 7/12/2023 Posts: 10221 Rating: (1177)	novotny.stanislav Dear Experts, does enybody idea how to get "week number" in PLC? I know that are many different systems how to define first week of the year, but in Europe is typical used: (the week with the year's first Thursday in it (the ISO 8601 definition)). http://en.wikipedia.org/wiki/ISO_week_date I need to print this number on customers product. best regards Stanislav Novotný Hello Stanislav, Look at this FAQ How can you read out the date and time with SFC1 (READ_CLK) In this way you can print exactly the date. For Nr. of week for example you must prepare coparing procedure and trace the date and when reach each Thursday to increase Nr. of week. Hope this help! regards

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1/15/2009 1:00 PM	Rate (0)
StanleyN Posts: 5 Rating: (0)	Hello UMENCHO, it is not so easy: 1. Customer want to have a special fomat of the print (shift, day of the week, week number, year) 2. First week of 2009 began Monday 29.12.2008 (because included first Thursday 2009). To trace for Thursday and increment week number is not right solution. I need rather calculation (equation). But thanks for reply P.S. Sorry for my English
StanleyN Posts: 5 Rating: (0)
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1/15/2009 1:31 PM	Rate (0)
UMENCHO Diamond Member Joined: 3/21/2006 Last visit: 7/12/2023 Posts: 10221 Rating: (1177)	Hello Stanislav, Let's try to explain my idea: With upper link you saw how we can detect the current time. Format of this date@time you can devide by bytes. Byte Nr8 will assign exactly day of week. If this equel to B#16#5 (this means Thurday) update one counter C0 with 1. In the beginning this C0 will be equel to 0. But let's say you prepare this program on 16.1.2008. In program you'll read that this is Friday, and must assign in C0 initial value (take fro calendar) equal to 3 ( this is third week of year). After that only decide on wich day for you'll be new week. For example: Manday. Comparing Byte Nr8 with 2 and if this is goes to 2 (only in positive edge) updete C0 with 1. And after that use this current value of C0 like Nr. of week. I hope to understand my idea. regards
	Last edited by: UMENCHO at: 1/15/2009 1:32 PM It''''s not necessary to start new week with Thursday. I put it only for example.
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1/15/2009 2:28 PM	Rate (0)
StanleyN Posts: 5 Rating: (0)	Hello UMENCHO, it is not so easy : 1. I know how to work with SFC1 and how to get information from Date&Time format. 2. It is possible to go in your way BUT this PLC works in a machine and I have no certainty that machine (PLC) will be ON every Monday 0:00 to catch positive edge. Operator can switch it OFF when he finish his job. That is the reason why I prefer another solution. I hope You understand me Regards
StanleyN Posts: 5 Rating: (0)
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1/15/2009 3:13 PM	Rate (3)
Denilson Pegaia Platinum Member Joined: 9/23/2005 Last visit: 9/29/2023 Posts: 4241 Rating: (1366)	Hi, sometime ago, I wrote a FAQ suggestion about the week of year. It was approved but not yet published. Here stay the preliminary version. You can adapt it for your necessity. Attachment week.zip (1137 Downloads)
	Last edited by: Pegaia at: 1/15/2009 3:14 PM Last edited by: Pegaia at: 1/15/2009 3:14 PM Denilson Pegaia Siemens Industry Sector Technical Support
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This contribution was helpful to 2 thankful Users StanleyN REDDY69

1/15/2009 4:46 PM	Rate (0)
Sydney Gold Member Joined: 1/4/2008 Last visit: 3/8/2023 Posts: 703 Rating: (96)	Hello, just an idea of another way... Read the actual date and timewith the SFC1, then prepare dummy DT variable: DT#yy-01-00-00-00-00-00-00(value isn't correct budshouldn't make trouble), where 'yy' copy from actual DT. Use DT_DATE (Standard library -> IEC Function Blocks, FC6) to convert both to DATE type. By subtraction you'll get the number of days in this year. So you have the number of days this year, you have the actual day and if you'll count little bit, then you'll get the number of the actual week... Regards Sydney

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1/15/2009 10:29 PM	Rate (1)
Gebhardt Karl Platinum Member Joined: 7/16/2006 Last visit: 7/27/2023 Posts: 1502 Rating: (176)	Do you have test the free library www.oscat.de Many Information for Date and time are in the Library. With Source-Code in SCL. A Code fore the "Week" is in the LIbrary to. It give an Library for Step7 and CoDeSys.
	Karl
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This contribution was helpful to 1 thankful Users StanleyN

1/16/2009 11:27 AM	Rate (0)
StanleyN Posts: 5 Rating: (0)	Hi all, thaks for all replies, especially to Denilson Pegaia and Karl Gebhardt for help . Problem solved . Regards Stanislav Novotný
StanleyN Posts: 5 Rating: (0)
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