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removing VSDs from S7 network
Created by: stephen.shelley@creativewater.com.au at: 10/6/2011 4:28 PM (2 Replies)
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| 10/6/2011 6:00 PM | |
Joined: 9/27/2006 Last visit: 3/23/2025 Posts: 12344 Rating:
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Hello stephen; The CPU still has the removed VFD slave in its configuration, and it is still attempting to connect to it though the network. When it does not find it (after a few retries) it declares a fault, and if you do not have OB86 in the CPU's program it will go to STOP mode. Check the diagnostic buffer of the CPU, it probably will advise you to add OB86 as a temporary measure, so that the fault on Profibus does not lead to a STOP (even though the diagnostic LEDs will still be active, and your scan time could be longer). Make sure you also remove all networks that access the VFD's inputs and outputs in your program, or you will have a different fault that could also make yougo to STOP mode (Area access). If the removal of the VFD is a permanent thing, you can resolve the issue permanently by changing the hardware configuration of the PLC and saving/compiling/downloading it to the CPU. If the removal of the VFD is a temporary thing, for repairs or maintenance, you could use SFC12 "D_ACT_DP" which deactivates the call of the slave in the DP-master's list so the bus does not go to fault in its absence: Notes for the use of the system function SFC12 "D_ACT_DP" If you need specificc help on how to do any of this, please let us know. Hope this helps, Daniel Chartier |
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| 10/6/2011 6:15 PM | |
Joined: 3/21/2006 Last visit: 3/19/2025 Posts: 10239 Rating:
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Even if removal is not a temporary, my advice is to go ahead with Daniel' suggestion using SFC 12. Is not a good thing to play with hardware configuration during production. Best regards, Hristo MIhalev |
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