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| 3/16/2010 1:51 PM | |
Joined: 9/27/2006 Last visit: 1/22/2025 Posts: 12330 Rating:
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Hellow Hawk; As long as the Profibus slave is part of the master's configuration, it will be accessed cyclically, and yes, there will be faults on the bus if you disconnect it. If the removal of the slave is temporary, you could use SFC 12 'D_ACT_DP', which de-activates a slave so the master does not call it; you therefore remove the irritant that causes BF and SF LEDs and disconnect the slave. You can use SFC 12 one acgain to re-activate the slave when required.See the following FAQ: http://support.automation.siemens.com/WW/view/en/17624225 If the removal is permanent, it would be advisable to change the master's Profibus-DP configuration and download it anew. Hope this helps, Daniel Chartier |
| 3/16/2010 2:14 PM | |
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Posts: 8 Rating:
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Thank you for reply, Daniel. I've already heard about SFC12, but I think I mustfirstsolve the "hardware problems". The tool in my press will be time to time exchanged for another one. And meanwhile the press must be working even without any tool present. So the press resp. the network will be sometimes without the slaves on the tool and if I just disconnect the Profibus line, the network won't beproperly terminated (physically). Then even if I deactivate the slaves on the tool there will be errors on the disconnected network because of some reflections or whatever... |
| 3/16/2010 5:08 PM | |||
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Joined: 9/27/2006 Last visit: 1/22/2025 Posts: 12330 Rating:
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Hello Hawk; Ahh, it wasn't clear to me that what you needed was a proper and permanent terminaton of the bus. And yes, removing the termination while the bus is powered will wreak havoc on the bus controller... So one option is to use an externally-powered termination module after the last node on the bus, such as this one:
Hope this helps, Daniel Chartier |
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| 3/17/2010 8:37 AM | |
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Posts: 37 Rating:
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Are +WZ1O and +WZ1U Racks on the same tool? If so, can you not make a profibus connection between them so you won't require terminating resisitor. |
| 3/17/2010 4:44 PM | |
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Joined: 9/27/2006 Last visit: 1/22/2025 Posts: 12330 Rating:
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Hello again Hawk; Thank you for the schematic, it explains a bit more of your problem. we faced something of the kind in our plants, when we had to connect Profibus-DP slaves that did not have a sub-D connector, and needed to be removed from the network on irregular or unpredictable sequence, for repair or maintenance; these were mainly valves and flowmeters on a piping system. The solution we finally implemented was based on Weidmuller T-connectors for Profibus-DP. Look at the following thread (last post contains product information): /tf/WW/en/Posts/37171 You can also look at the following product presentation to see how this T-connector works: http://www.voltimum.co.uk/news/12954/cm/weidmuller-profibus-dp-distributor-designed-for-use-with-steel-wire-armoured-cable.html The particular model illustratrated here is for steel-armoured Profibus cable, designed for harsh environments, which could be useful in your machine setting. But we used other models, for standard cabkle, with or without integrated termination. Basically, you use the T-connector to create a spurline (as short as possible) to which your slave will be connected. The main Profibus-DP trunck continues to the next slave, so that when the spurline is disconnected the network is not affected (although diagnostics will still be called for that missing slave). Hope this helps, Daniel Chartier |
Last edited by: dchartier at: 3/17/2010 4:44 PM |
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