3/27/2016 4:31 AM | |
Joined: 9/27/2006 Last visit: 9/22/2024 Posts: 12282 Rating: (2684) |
Hello KhanhLe; Chapter 4 (Active Components) of the following manual discusses the RS-485 repeater in Profibus networks: SIMATIC NET PROFIBUS Network Manual System Manual https://support.industry.siemens.com/cs/ww/en/view/35222591 The attachment below shows the connection of a repeater in a similar configuration to what you are describing. What you are actually doing by using the repeater is diving the network in 2 separate segments. Segment 1 attaches to connectors A1/B1 on the repeater, Segment 2 starts at A2/B2, as you surmised. Note that terminations are required at the beginning and end of each segment, so both termination resistors on the repeater are ON, as well as the terminations on the start and end modules on each segment. Hope this helps, Daniel Chartier |
Last edited by: dchartier at: 3/27/2016 4:41:44 AM |
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3/27/2016 7:44 PM | |
Joined: 9/27/2006 Last visit: 9/22/2024 Posts: 12282 Rating: (2684) |
Hello KhanhLe; For MPI and Profibus you would use the same connections as shown in the document above (A1/B! for Segment 1, A2/B2 for Sement 2), and make sure that all required terminations for both segments are respected, as shown in the above attachment. However, you must note a subtle difference on the physical layer, that makes MPI networks different from Profibus-DP networks: the line drivers used for MPI are not isolated, therefore the distances covered with MPI must not exceed 50m per segment. One exception: if you install 2 repeaters without any MPI nodes in that segment, the unoccupied cable can run up to 1000m. Here is an interesting FAQ that confirms this information: What should you watch out for when using the RS485 repeater in PROFIBUS and MPI bus systems? https://support.industry.siemens.com/cs/ww/en/view/37627 Configuration Notes: Between nodes with isolated MPI interface the line length of a segment can be up to a maximum of 1000m, provided the transmission rate of 187.5 Kbaud is not exceeded. (note: this describes the situation where 2 repeaters are linked by Profibus cable for MPI segments, without MPI nodes between them. See the attached drawing. Hope this helps, Daniel Chartier
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3/28/2016 5:12 PM | |
Posts: 153 Rating: (9) |
Hello dchartier picture show mpi system |
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