6/29/2013 8:48 PM | |
Joined: 6/14/2013 Last visit: 3/18/2023 Posts: 218 Rating: (9) |
Thank youAMAZINGAHMED. Can you give me an example? thanks |
6/29/2013 9:38 PM | |
Joined: 8/27/2006 Last visit: 4/13/2024 Posts: 719 Rating: (88) |
I don't have access to my PC (with installed Siemens software) but I will try to demonstrate. First you create a tag with the flying weight and save the flying weight value inside it (e.g. 2.1 Kg) which is the weight between the valve and the weigher. Second you subtract the flying weight value from the setpoint value (e.g. if you want to weigh 200 Kg, then the result will be 200 - 2.1 = 197.9 Kg). Third, compare the actual read weight with the setpoint. Close the valve when the weight reaches 197.9 Kg). The rest of the 200 Kg will be flying from the valve to the weigher after you close the valve. At ideal conditions, you should read 200 Kg every time, but life is not ideal because the value of the flying weight can change due to humidity and temperature or any other parameters. An advanced modification will be re-calculating the flying weight after every weighing cycle. e.g. if the result was 200.2 Kg, then you can write in the flying weight 2.1 + 0.2 = 2.3 Kg for the next weighing cycle. You should repeat this after every weighing cycle. Another method of recalculating the flying weight is to add half of the result error to the existing flying weight (e.g. if the result was 200.2 Kg, then add 2.1 + (0.2/2) = 2.2 Kg, and this will give you less fluctuation in flying weight calculation. I hope that was clear
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This contribution was helpful to3 thankful Users |
6/29/2013 10:33 PM | |
Joined: 6/14/2013 Last visit: 3/18/2023 Posts: 218 Rating: (9) |
Here is a test. OK? ... |
6/30/2013 3:27 AM | |
Joined: 5/28/2008 Last visit: 4/15/2024 Posts: 4505 Rating: (835)
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Hello, I am agree with AMAZINGAHMED that we shouldn't assume that every thing is ideal. So, I think it would be better to have two valves. One for coarse (Big valve) and another one for Fine (Very small valve). Both of them will be opened until reach to 90% of set point weight. Then close the big valve and keep only the small one. until Actual weight = Setpoint weight - (flying weight). Please see the attached slide.
AttachmentSlide.zip (133 Downloads) |
Ayman Elotaify |
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6/30/2013 7:44 PM | |
Joined: 6/14/2013 Last visit: 3/18/2023 Posts: 218 Rating: (9) |
Thank you for your advice. Here is an approach ...
Attachmentprogram.zip (113 Downloads) |
7/1/2013 8:22 AM | |
Joined: 8/27/2006 Last visit: 4/13/2024 Posts: 719 Rating: (88) |
you can use the attached example as a template.
Attachmentmini_batch.zip (104 Downloads) |
The more you know, The more you know that you don't know |
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7/1/2013 11:33 AM | |
Joined: 6/14/2013 Last visit: 3/18/2023 Posts: 218 Rating: (9) |
thank you AMAZINGAHMED I will follow these indications and see what I can do. Thanks. |
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