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12/19/2012 10:54 PM | |
Joined: 9/27/2006 Last visit: 8/17/2024 Posts: 12277 Rating:
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Hello Milos; There are 3 kinds of participants on a Profibus-DP network, slaves, masters Class 2 (your HMI) and Masters Class 1 (your PLC in this case). On startup, one of the roles of a Master Class 1 is to send configuration data to all slaves, and bus speed to all participants. This configuration data has beenprepared in the Profibus configuration software and has been downloaded to the Master Class 1.So you should have to change the bus speed settings only in the master's Profibus configuration. Do not forget to save anddownload the hardware configuration to your PLC for these settings to take effect; the PLC will have to be in STOP mode for the download to work. See the following document from ISA fpor more details on startup od a Profibus network: Basics of PROFIBUS Operation - ISA Now, you need a repeater on a Profibus network when either of the 2 following conditions appear: - you have exceeded the maximum length of a segment at the speed you have selected; - you have exceeded a maximum number of 32 nodes on a segment (toreach the maximum number of slave (125) on a Profibus-DP network you need repeaters...). The first condition would proobably be cleared at 187,5 kBd, you should be able to have segments a kilometer long. But if the repeater is installed after 32 nodes or more, you could still have troubel with network stability. So it would be good that you locate this equipment both physically and in the bus, to make sure you respect that condition also. Hope this helps, Daniel Chartier |
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8/8/2016 2:57 PM | |
Joined: 9/3/2014 Last visit: 3/13/2019 Posts: 4767 Rating:
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New question published by yknott is split to a separate thread with the subject Faults on Profibus network, possible to reduce the speed?. Best regards |
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