5/19/2014 2:41 PM | |
Joined: 11/26/2011 Last visit: 6/29/2023 Posts: 508 Rating: (22) |
These topic has been discussed in more detail here. |
5/20/2014 5:11 PM | |
Joined: 1/23/2012 Last visit: 3/29/2024 Posts: 31 Rating: (0) |
Hello Mr.Jens_app, Thanks for reply . I am using Simatic Manger software for Programming . Regards, Arunram Vasudevan
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5/20/2014 5:41 PM | |
Joined: 1/23/2012 Last visit: 3/29/2024 Posts: 31 Rating: (0) |
Dear Mr.Jens_app, I wanted to explain my poblem little bit better . The value i enter in the scada screen will change everytime . Before power off the PLC if the value is 42 which i set in IO field, after the PLC switch OFF and switch ON i need the same value to retain . What happening now is When switch off and switch on the PLC value appear is in the Actual value of DB . Regards, Arunram Vasudevan
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5/20/2014 6:44 PM | |
Posts: 101 Rating: (0) |
you need to make your DB retained by make the following 1-go to cpu properties 2-select retentive memory tab. 3-write your db number and specify your tag address. so this adress will keep its value even if power off. thanks mohamed elokby |
5/20/2014 8:31 PM | |
Joined: 1/5/2011 Last visit: 4/22/2024 Posts: 815 Rating: (121) |
Hi Arunram, Setting the retain property of your datablock will exactly do what you want. Upon a warm restart (mode switch from stop to run) the cpu deletes all the non-retentive bit memories, timers, counters and sets the non-retentive data to the start values of the load memory (initial values). But when a datablock is set to retain the cpu will "remember" which value is last active and will retain this value on restart. In a cpu 319 all datablocks are automatically set retentive except when selected otherwise, see screenshot1. Now when you go to the CPU properties you can set other retentive memory areas (MB's, timers and counter), notice that the retentive DB area is grayed out (see screenshot2), this is because all DB's are automatically set to retain except when selected otherwise (screenshot1). So make sure the retain settings are done correctly and most likely your issues will be solved. I hope this helped. Kind regards, Jens
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Keep it simple and on-topic. |
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