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| 3/4/2009 8:13 AM | |
Joined: 9/27/2006 Last visit: 1/22/2025 Posts: 12330 Rating:
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Hello Chris; The configuration rule for OLMs in a redundant ring topology is explained in the following attachment. It is extracted from the following manual, "Simatic Net Twisted-Pair and Fiber-Optic networks": http://support.automation.siemens.com/WW/view/en/8763736 Basically, up to 11 OLMs can be configured in a redundant ring (so with 10 you are within these limits); the totallength of the subsequent RS-485 cable and the fiber is the next thing to evaluate, as per the explanation you can read up in the manual. The number of nodes must of course respect the Profibus-DP norms. Hope this helps, Daniel Chartier |
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| 3/5/2009 6:29 AM | |
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Joined: 9/27/2006 Last visit: 1/22/2025 Posts: 12330 Rating:
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Hello Chris; Sorry if my earlier intervention was not clear . The rules apply to the Tbit parameters that must be adaptedin the Profibus configuration withOLMsina redundant ring. The number of nodes to be addressed on the bus must never exceed the Profibus limitations (max. nodes 126), and the HSA must actually be reduced to the lowest range possible (if you have 26 nodes, then HSA=32) to reduce the time the master uses to call non-existant nodes. This should also apply to your double rings situation also. Have a look at the following document, it resumes the configuration calculations for OLMs in different topologies; especially look at the redundant ring calculations, with RS-485 segments of more than 20 m. http://support.automation.siemens.com/WW/view/en/1995199 Hope this helps, Daniel Chartier |
| 5/4/2009 11:22 AM | |
Joined: 1/28/2008 Last visit: 11/30/2024 Posts: 1 Rating:
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Hello! I have read that up to 122 OLM modules can be in a ring.. why only 11? thanks for the answer |
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