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Retentive memory

Created by: Mislec at: 12/8/2009 9:22 AM (5 Replies)

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12/8/2009 9:22 AM	Rate (0)
Mislec Posts: 9 Rating: (0)	Hi, I'm using the s-7 1200 for my home automation project and I have a problem with the retentive memory. I have a non symbolic db1 with checked retain setting but the controler doesn't keep the values after a restart or power off. Regars, Kristijan
Mislec Posts: 9 Rating: (0)
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12/8/2009 12:53 PM	Rate (0)
Robster Gold Expert Joined: 5/28/2008 Last visit: 10/23/2024 Posts: 1343 Rating: (141)	Hi, in a non-symbolic DB the retain setting applies to all variables in DB. Either you have all variables as retain or none. So if you click the retain box at one varaible, all the other one are also retain. And then, normally it should work if you switch power off/on. Maybe in project your variables will be overwritten at startup. The retain is also lost by uploading project again. regards

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12/9/2009 3:23 PM	Rate (0)
Wright Posts: 7 Rating: (0)	Hello. If your project has a combination of symbolic and non-symbolic DBs, you may be losing data due to a known problem with retentive data. Update V1.0.1 fixes the problem. It's available on the Product Support page for the S7-1200. It's called "Operating system updates for CPU 12xxC..."
Wright Posts: 7 Rating: (0)
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12/9/2009 3:32 PM	Rate (0)
Robster Gold Expert Joined: 5/28/2008 Last visit: 10/23/2024 Posts: 1343 Rating: (141)	Here the link for the thread of "wright". [url]http://support.automation.siemens.com/WW/view/en/34612486/133100[/url]
	Last edited by: Robster at: 12/9/2009 3:32 PM
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12/21/2009 8:50 AM	Rate (0)
Mislec Posts: 9 Rating: (0)	Could I make the firmware update without the 24 MB memory card, because the memory card is really expensive. I also put my project in the attachment. Could you please take a look if i have some error in the configuration. Best regards, Kristijan Attachment Krmiljenje_hiše.zip (547 Downloads)
Mislec Posts: 9 Rating: (0)
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12/21/2009 5:16 PM	Rate (0)
Wright Posts: 7 Rating: (0)	Hi, Mislec. I tried your project. In Device configuration, I changed the Startup mode parameter to No restart. Icompiled and downloaded. I put the PLC in RUN and monitored data in the DB and saw changing values. I selected Go offline and recorded last values in the DB. Ipower-cycled the PLC, andI selected Go online and monitored data in the DB. All of the data was retained (i.e., it matched the recorded values from before the power-cycle). I put the PLC in RUN (as if power-cycled with Startup mode set to RUN), and DB values were updating again (i.e., different than retained). I also tried the above steps with a manual change to the value of Prenos_grelec, and its value was retained after the power-cycle but not after going to RUN -- because Network 13's CONV instruction over-writes the value each scan. In short, I do not see a problem with retentive data, and I the firmware update will not help this situation. Kind regards
Wright Posts: 7 Rating: (0)
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