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| 3/17/2014 7:33 AM | |
Joined: 1/21/2013 Last visit: 10/23/2024 Posts: 4620 Rating:
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Hi lupercus23, it would be nice to know what kind of communicationMeanwhile look at this: What are the options for exchanging data between CPUs via MPI/PROFIBUS DP? |
| 3/17/2014 8:38 AM | |
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Joined: 1/21/2013 Last visit: 10/23/2024 Posts: 4620 Rating:
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Hi lupercus23, Look here |
| 3/17/2014 9:36 AM | |
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Posts: 16 Rating:
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i'm doing based on that . What are we reading and writing here ? I/O's or the DB blocks ? |
| 3/17/2014 2:31 PM | |
Joined: 1/28/2009 Last visit: 10/26/2024 Posts: 6852 Rating:
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Hello, I just explain a bit about using SFC14/SFC15 in this Picture (I think it is one of masterpieces of fritz).Those mentioned functions are used when you want to read more that 4 bytes (or 3 bytes).The reason may come from the consistency of data.As illustrated graphically in the Picture , 5 bytes of consistent data are copied form DB15.DBB3(and next 4 bytes) output address QB103 (and next 4 byte) in master side.This task is done by SFC15,Please consult with the online manual for more help regarding the parameters. In the slave side, data is available to be read from IB3(and next 4 bytes).Data is read by SFC14 and transferred to 5 byte area in DB14 starting with DB14.DBB3.Testing the whole procedure is only possible via a real hardware and I hope this explanation helps. Best regards, Hamid Hosseini |
Last edited by: hdhosseini at: 3/17/2014 2:35 PM |
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| 3/18/2014 6:51 AM | |
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Posts: 16 Rating:
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ok , i got it. What about the consistency issue .I have seen that in sfc14/15 and not discussed in Bsend/Brecv and similar functions . |
| 3/19/2014 5:46 AM | |
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Joined: 1/28/2009 Last visit: 10/26/2024 Posts: 6852 Rating:
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Hello, Data consistency is ensured by function itself or can be evaluated by user program based on the check signals (Done, error,Status) in output of a given function.Read more, as a sample discussion on consistency, in Chapter 9 HERE. Best regards, Hamid Hosseini |
Last edited by: hdhosseini at: 3/19/2014 7:44 AM// typo |
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| 3/20/2014 8:49 AM | |
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Posts: 16 Rating:
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hi ,all i'm attaching a program file for 300 to 400 MS comm done with simatic v5.5 . I tried to send word value from 400 to 300 over profibus DP link ,its a modification of a program i downloaded from this forum . can you figure it out why the values are not being sent ? Attachmentcomm__Pr.zip (195 Downloads) |
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