5/11/2006 9:12 AM | |
Joined: 4/24/2006 Last visit: 8/23/2024 Posts: 8723 Rating:
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Hello, If you' re using a CPU with MMC, it's important to know the firmware! If the firmware < 2, then a DB keeps automatically the actual value (retentive) If the firmware > 2, then the following: You can change the properties of the DB in Step7 (beginning with v5.2 + sp1) whether a DB at Power On/Off or RUN/STOP * keeps the actual value (retentive) * accepts the initial value (non retentive) Some information about SFC84, is found in the following manual: http://support.automation.siemens.com/WW/view/en/1214574 Ps: Be careful with writing to the MMC, because it's limited. Hope this will help you, Best regards Wizard |
5/15/2006 9:22 AM | |
Joined: 4/24/2006 Last visit: 8/23/2024 Posts: 8723 Rating:
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Hi, The PLC functions as follows: When the power is cut off, the actual value's of the DB are saved on the MMC. Find out in the following links: http://support.automation.siemens.com/WW/view/en/17602317 http://support.automation.siemens.com/WW/view/en/22295462 And the following manual, explains the retentive area's of the S7-300: http://support.automation.siemens.com/WW/view/en/12996906 See chapter 4. Hope this will help, Wizard |
7/3/2006 11:26 PM | |
Posts: 101 Rating:
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I had a weekend data loss last week.yeh i cant remember a thing. I attribute that to copious amounts of alcohol.[;)] |
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