3/26/2010 2:00 PM | |
Joined: 4/24/2006 Last visit: 8/23/2024 Posts: 8723 Rating:
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Dear Bogdan, You can use the right Organisation Blocks Which organization blocks do you need for error handling? Start with OB86 and OB122 Best regards, Wizard |
3/26/2010 2:50 PM | |
Joined: 9/27/2006 Last visit: 8/23/2024 Posts: 12279 Rating:
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Hello Bogdan; Whenever you CPU enters STOP mode, diagnostic entries are written to the Diagnostic buffer, to allow the user to understand the sequence of events that led to the controller stop. So opening, deciphering and understandingthe Diagnostic buffer should be your first reflex whenever such a situation occurs. That being said, S7 CPUs also use a specal mechanism to gather data from events that can put the CPU in STOP mode: diagnopstic OBs. Specifically OB80, OB81, OB82, OB83, OB84, OB85, OB86, OB87, OB121, OB122; like all S7 OBs, they are not called by the user, but by the operating system when a specific event happens. For example, OB86 is called when a configured DP slave is found missing; If OB86 is found in the CPU's memory then it will gather the details of the missing slave and place them in the Diagnostic buffer; if it is missing from the CPU's memory, then the processor will enter STOP mode and you will find in the diagnostic buffer a line stating "Missing OB86". So you will have to create and download (no internal program necessary at this point) to the CPU's blocks this OB86 for the CPU to continue running (even with the diagnostic LEDs lit) while the slave starts up. See the following FAQ for more details and links about the diagnostic OBs: http://support.automation.siemens.com/WW/view/en/33118603 Now, if the shining LEDs bother you still, you could also (after loading the correct OBs in the processor) use SFC12 "D_ACT_DP" to stop the CPU from calling the missing slave for a long enough time for it to come online, at the startup of the system. This would make thesystem very stable; you can use SFC 12 a second time to re-activate the slave at this point. Look up the details of SFC 12 in the Online Help of Sytep 7 or in the manual System and Standard Functions (available in the Simatic Documentation folder of the PC you have installed Step 7 on). Hope this helps, Daniel Chartier |
Last edited by: dchartier at: 3/26/2010 2:51 PM |
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3/26/2010 2:58 PM | |
Posts: 13 Rating:
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How can I increase CPU315 verification period, the Profibus network for that driver to become ready? Have a similar example? Thank you! |
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