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Array of Bool and Word with AT command

Created by: MAIDEL at: 6/20/2014 6:39 AM (15 Replies)

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6/20/2014 6:39 AM	Rate (0)
MAIDEL Posts: 19 Rating: (0)	Hello everyone, I am working on TIA Portal V11 (SP2 Update 5), and I am using a AT command in WORD (or an INT) in order to access each BOOL of this one (Array [0..15] of Bool. My problem is that the first bit of the array is matching the bit 8 of the WORD the 2 bytes of the WORD are inverted. How can I solve this problem See the attachement picture we can see it Thanks Attachment Array_of_Bool_From_WORD_or_INT.jpg (5471 Downloads)
MAIDEL Posts: 19 Rating: (0)
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6/20/2014 8:17 AM	Rate (2)
William_B Posts: 5225 Rating: (1182)	MAIDEL Hello everyone, I am working on TIA Portal V11 (SP2 Update 5), and I am using a AT command in WORD (or an INT) in order to access each BOOL of this one (Array [0..15] of Bool. My problem is that the first bit of the array is matching the bit 8 of the WORD the 2 bytes of the WORD are inverted. How can I solve this problem See the attachement picture we can see it Thanks Hi, There is a problem with the overlay. Please see if the following links help.. LINK 1 Parts and attachments of 6/19/2014, 12:52 PM and 6/19/2014, 3:35 PM LINK 2 Remember.. * Use "AT" in FB not in global DB * Should NOT be set to "optimized" when creating the FB * Declare WORD variable as STAT * Below this.. declare {array name} with the type as "AT" * The "AT" will move away to the left and open the type entry again. * Now write (again) inside the type entry ARRAY of BOOL. I hope this is not too cryptic. Tell us if it is - then someone will help you later with a step-by-step. Greetings. w
William_B Posts: 5225 Rating: (1182)
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6/20/2014 9:50 AM	Rate (4)
Jens_app Gold Member Joined: 1/5/2011 Last visit: 10/27/2023 Posts: 814 Rating: (120)	MAIDEL Hello everyone, I am working on TIA Portal V11 (SP2 Update 5), and I am using a AT command in WORD (or an INT) in order to access each BOOL of this one (Array [0..15] of Bool. My problem is that the first bit of the array is matching the bit 8 of the WORD the 2 bytes of the WORD are inverted. How can I solve this problem See the attachement picture we can see it Thanks Hello Maidel, this is perfectly normal, you are overlaying a word with an array, but both are different in structure. Let me explain: a word consist of two bytes, byte 0 and byte 1. Byte 0 contains bits 8 to 15 and Byte 1 contains bit 0 to 7. Which means in a word bit numbering is done in the other direction than byte numbering. for an array its different, the first byte of your array(byte 0)will containt bits 0 to 7 and the second byte (byte1)will contain 8 to 15. You see, the ordering ofbytes happens differently for an array and a word. I've attached an image wich will clarify this a bit more, and added a sample with you case. Now the thing you can do if you want your bytes in different order, is just swap those two bytes. So switch byte 0 of your array with byte 1. I don't know what you are doing further in your program, so I don't know if you need to switch the bytes or can work with the word as it is now. I hope this explains it all. Kind regards, Jens Attachment arrayvswordvsAToverlay.pdf (2303 Downloads)
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6/20/2014 12:14 PM	Rate (1)
William_B Posts: 5225 Rating: (1182)	Jens_app I've attached an image wich will clarify this a bit more, and added a sample with you case. Jens, Thank you for schooling me with that post of yours. I slightly forgot about that one. Now please allow me to show you something. I created a TIA V13 program to ran a simulation. The result is shown with commentary in the attached JPG. It is the AT overlay with the block access set to "optimized". The pros and cons are also mentioned within the JPG. Enjoy. w. Attachment Visual clues_Using AT overlay in FB with optimised block access.jpg (3207 Downloads)
William_B Posts: 5225 Rating: (1182)	Last edited by: William B. at: 6/20/2014 12:16 PM @Jens: Thank you very much for the sketch. You prove we (forum members) can use hand sketches to explain better.
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6/20/2014 2:19 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 12/7/2023 Posts: 13989 Rating: (2282)	William B. Jens_app I've attached an image wich will clarify this a bit more, and added a sample with you case. Jens, Thank you for schooling me with that post of yours. I slightly forgot about that one. Now please allow me to show you something. I created a TIA V13 program to ran a simulation. The result is shown with commentary in the attached JPG. It is the AT overlay with the block access set to "optimized". The pros and cons are also mentioned within the JPG. Enjoy. w. The AT overlay will only work when the bool/byte/word/dword values are in predictable memory locations. Using optimized access distributes the bits/bytes/words/dwords in ways that may prevent the AT overlay from mapping everything together. Uncheck the optimized access (while offline), and compile/download and try again.
	science guy
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6/20/2014 2:35 PM	Rate (0)
William_B Posts: 5225 Rating: (1182)	huggy_d1 The AT overlay will only work when the bool/byte/word/dword values are in predictable memory locations. Using optimized access distributes the bits/bytes/words/dwords in ways that may prevent the AT overlay from mapping everything together. Uncheck the optimized access (while offline), and compile/download and try again. Hi. Sorry my last entry was not to answer the original question as to further the discussion in more general terms. What I wish to show (maybe academical) is that the optimized access is not a must anymore in TIA V13. Please see the attached extract from the manual STEP 7 Basic V13.0, System Manual, 02/2014, page 119. Please note the highlighted section. The downfall of the method is that there is not the traditional order of byte addresses for teh entire DB, but only for the borders of the AT overlay. I do hope this clears up some confusion. ..maybe this discussion should rather split to anther post. Greetings. w Attachment EXTRACT_STEP_7_Basic_V13_enUS_en-US.pdf (935 Downloads)
William_B Posts: 5225 Rating: (1182)
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6/20/2014 2:43 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 12/7/2023 Posts: 13989 Rating: (2282)	William B. huggy_d1 The AT overlay will only work when the bool/byte/word/dword values are in predictable memory locations. Using optimized access distributes the bits/bytes/words/dwords in ways that may prevent the AT overlay from mapping everything together. Uncheck the optimized access (while offline), and compile/download and try again. Hi. Sorry my last entry was not to answer the original question as to further the discussion in more general terms. What I wish to show (maybe academical) is that the optimized access is not a must anymore in TIA V13. Please see the attached extract from the manual STEP 7 Basic V13.0, System Manual, 02/2014, page 119. Please note the highlighted section. The downfall of the method is that there is not the traditional order of byte addresses for teh entire DB, but only for the borders of the AT overlay. I do hope this clears up some confusion. ..maybe this discussion should rather split to anther post. Greetings. w w Thanks for the post. So now with V13 we can get predictable behavior if the interface is set to "Set in IDB" checkbox is checked. That is good to know. I have barely started using V13 and stopped after it corrupted a V12 project. Apparently a recent update fixed that problem and made V12 compatibility mode work similar to V12 after SP1 no longer corrupted V11 projects. I guess it is time to get up to speed, but sadly, 95% of my projects are V11 and V13 is not compatible with V11. If it were,V13 would be adopted where I work much faster.
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6/20/2014 2:54 PM	Rate (0)
William_B Posts: 5225 Rating: (1182)	huggy_d1 ..I guess it is time to get up to speed, but sadly, 95% of my projects are V11 and V13 is not compatible with V11. If it were,V13 would be adopted where I work much faster. ..ouch. We gave V12 a skip.. the V11 is however a worrying factor. We run V11 and V13 in parrallel -- a V13 license allow both V11 and V13 even with multiple instances of each. w
William_B Posts: 5225 Rating: (1182)
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6/20/2014 2:58 PM	Rate (0)
William_B Posts: 5225 Rating: (1182)	Back on original topic.. Date code: 6/20/2014, 2:52 PM.. from LINK for a step by step to create AT overlay. Please say THANKS to the author of the refferenced post. w
William_B Posts: 5225 Rating: (1182)
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6/20/2014 7:03 PM	Rate (0)
MAIDEL Posts: 19 Rating: (0)	Jens_app MAIDEL Hello everyone, I am working on TIA Portal V11 (SP2 Update 5), and I am using a AT command in WORD (or an INT) in order to access each BOOL of this one (Array [0..15] of Bool. My problem is that the first bit of the array is matching the bit 8 of the WORD the 2 bytes of the WORD are inverted. How can I solve this problem See the attachement picture we can see it Thanks Hello Maidel, this is perfectly normal, you are overlaying a word with an array, but both are different in structure. Let me explain: a word consist of two bytes, byte 0 and byte 1. Byte 0 contains bits 8 to 15 and Byte 1 contains bit 0 to 7. Which means in a word bit numbering is done in the other direction than byte numbering. for an array its different, the first byte of your array(byte 0)will containt bits 0 to 7 and the second byte (byte1)will contain 8 to 15. You see, the ordering ofbytes happens differently for an array and a word. I've attached an image wich will clarify this a bit more, and added a sample with you case. Now the thing you can do if you want your bytes in different order, is just swap those two bytes. So switch byte 0 of your array with byte 1. I don't know what you are doing further in your program, so I don't know if you need to switch the bytes or can work with the word as it is now. I hope this explains it all. Kind regards, Jens I could't answer, I was on commissionning, I would like to be able to read and write some bits of words, so to avoid to use ROR or ROL fonction, I finally used this kind of syntax: <name_of_the_variable>.x0 or (.x1 for bit 1, X2 for bit 2 ..) see this FAQ : https://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo&lang=en&objid=57374718&caller=view Thank you everyone for your contributions. It seems that this thread was interesting Have a good week end see you
MAIDEL Posts: 19 Rating: (0)	Last edited by: MAIDEL at: 6/20/2014 7:08 PM
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