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2/18/2009 5:28 AM | |
Joined: 9/27/2006 Last visit: 7/7/2024 Posts: 12268 Rating:
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Hello Chris; Wiring considerations for Pofibus-PA are different than for Profibus-PA. I have attached a small file that gives the major points to follow for PA installation (also valid for Fieldbus Foundation, as they both share the same physical layer definitions; note that the power supply conditionning suggestions in the document only apply to FF, PA takes care of that at the FDC {IM 157]level). Basically, DP is designed as a daisy-chained bus,one cable going into the slave, another one leaving to the next node. PA is a Trunk and Spur bus that can be connected in 2 ways: -using Siemens SplitConnect technology, using T-taps on the trunk to connect a spur to the PA slave -using terminal blocks (originally designed for FF) to connect multiple spurs to a junction box in a so-called Chicken-Foot design. Both work well, it is generally a client-preference choice. in our case, our client likes the junction-box topology, as his operators are used to this setup with analog signal cables. So we use MTL Megablocks (with integrated surge protection) inside local juction boxes throughout our plants, connecting various PA nodes to different terminals of a MegaBlock. In both configurations only a single cable (spur) connects to the PA slave, "dropping" from the main (trunk) PA cable connected to the FDC (PA coupler device). Remember to use correct terminations and suggected cables for PA (Siemens and Belden are our regular providers)to ensure that you maintain the best signal over the greatest length (can be up to 1900 m, adding the trunk length and all spurs). Hope this helps, Daniel Chartier AttachmentInst_Guide_PA_2092_V22_Feb03.pdf (296 Downloads) |
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