7/24/2009 10:23 PM | |
Joined: 12/22/2006 Last visit: 1/25/2022 Posts: 1742 Rating: (308) |
Hello, There is a difference between "modifying" and "forcing". You canModify and force in run. In this manual, http://support.automation.siemens.com/WW/view/en/18652056 Chapter 20.8.3 explain the differences between forcing and modifying. When modifying, chapter 20.7.2, they explain that You can choose the trigger point ( = when you modify) and the frequency (modify once, or cyclically). This is importnat because when modifying, it might be thatwhat youmodify is written back by the program or the refresh of process image. Forcing is explained in chapter 20.8 Forcing means that you can assign fixed values to individual variables of a user program so that they cannot be changed or overwritten even by the user program executing in the CPU. |
Best regards |
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This contribution was helpful to1 thankful Users |
7/25/2009 9:16 PM | |
Posts: 8946 Rating: (999) |
100% agree. |
7/26/2009 12:44 AM | |
Joined: 7/2/2008 Last visit: 8/26/2024 Posts: 928 Rating: (308) |
Hello Lalit, This it to make you more careful. Bhaskaran has already sounded alarm.
I know an instructor in Siemens who says if it was in his hands he would have deleted FORCE from course contents and he always make it the last thing to teach. It's very risky and if you are not fully aware of Machine/Process interlocks and sequences you may destroy something. I hope you just take care and try to avoid FORCE as much as you can. Best regards. H-H |
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