6/21/2009 1:07 PM | |
Joined: 10/7/2005 Last visit: 9/23/2024 Posts: 3021 Rating: (1054) |
Hello again gumis
You need to change the way you are thinking about communication. Any message on the Profibus is always "seen" by all stations. Since the message contains the Destination Address (amongst other things) only the station that has that address will accept it and issue a reply message. While it may not make sense for the Master to send a message on the bus that in this case he himself won't even "see" (unlessof course you have really bad reflections on the bus but lets not discuss this though further) nor will be "answered" by anyone else (as it is technically a message for himself), he'll send this "pass token back to myself" message out anyhow (he has to do it as it is part of Profibus standard that a token passing must take place between masters). Cheers Fritz |
Cheers |
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6/26/2009 2:15 AM | |
Joined: 10/7/2005 Last visit: 9/23/2024 Posts: 3021 Rating: (1054) |
hello gumis allow me toquote myself from an earlier post of this thread to answer your question 1:
As for question 2: Yes it could also be the 6 byte long FDL status request that you captured, please don't "blame" Anchobi for NOT spending hours trying to exactly decipher the oscilloscope screen capture whose resolution is not all that accurate (I give hime a lot of credit for realising that it is NOT the SD2I/O message frame). I hope this helps cheers fritz |
Last edited by: fritz at: 6/26/2009 2:16 AMCheers |
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This contribution was helpful to1 thankful Users |
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