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10/13/2010 6:10 PM | |
Joined: 10/25/2005 Last visit: 7/2/2024 Posts: 25 Rating:
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in a small plant, I have a S7 300/319-3 PN-DP as profibus master of some slaves (inverters and I/O), nothing special, from my point of view. In spit of this, I received the following comment from the Customer, after commissioning and startup successfully completed (!) "No deviations were found, except one: the results show that some of the cables are shorter than 1 meter. Normally the cables between two devices should be longer than 1 meter, otherwise transfer errors may occur depending on the Baud transfer rate." can anybody confirm this issue and give me any reference to an official simatic document/manual confirming or denying ? thanks a lot Splitted from Profibus DP cable Length measurement. |
Last edited by: O_Moderator at: 10/14/2010 1:25 PMnew subject after splitting |
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10/13/2010 7:45 PM | |
Joined: 9/27/2006 Last visit: 7/17/2024 Posts: 12268 Rating:
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Hello ecsiberg; You will find this minimum value stipulated here, in the "Profibus Cabling Guidelines", by the Profibus Interface Center, Johnson City, TN, revision 0.4, page 7:https://www.sea.siemens.com/us/internet-dms/Internet/microsites/pic/general/docs/PICPROFIBUSCablingGuide.pdf C. Special requirements for baudrates >1.5 MBaud Use of baudrates greater than 1.5 MBaud requires special connectors. The connector must have built in Inductors in order to run with higher baudrates. Spur lines are not allowed when using baud rates greater than 1.5 MBaud. The maximum length between segments at 12 MBaud when using copper cable is: 100m / 327feet. The maximum length between optical link components is: 300m / 981feet In some applications, several bus connectors are used at electrically short distances. A minimum cable length between two stations of 1m/ 3feet is recommended. Hope this helps, Daniel Chartier |
10/15/2010 5:14 PM | |
Joined: 10/25/2005 Last visit: 7/2/2024 Posts: 25 Rating:
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great! thanks Daniel this is exactly what I needed best regards EC |
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