4/24/2012 10:23 AM | |
Posts: 6 Rating: (0) |
TIBI68
Sketch attached. Set-up plenty of networks with one master, just never had to use multiple masters before, and reviewing this proposal for an MCC interface from three standalone master systems! Thanks John AttachmentMPCS Interfaces.pdf (153 Downloads) |
4/24/2012 11:54 AM | |
Joined: 12/1/2009 Last visit: 9/5/2024 Posts: 672 Rating: (147) |
Hi John, I just had a quick look at this link. https://support.automation.siemens.com/NL/llisapi.dll?func=cslib.csinfo&lang=en&objid=59883814&caller=view In case you use yoursimocode's with the PN interface a similar layout to yours will be possible. Of course with switches instead of OLM's and CPU's with integrated or external PN interface. Regards. |
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4/24/2012 3:21 PM | |
Joined: 10/7/2005 Last visit: 9/20/2024 Posts: 3021 Rating: (1054)
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Hello jduffy132 confirmed, you can use OLM's in your Network and have three Masters on one side of the OLM link and various DP Slaves on the other side(or could even have a mix of DP Masters and Slaves on either side). What you have is simply aMultimaster DP Network and your OLM link is a simple part of the Network infrastructure (if you had one PLC and two HMI's on the same Profibus, you'd for example also have a Multimaster system and probably wouldn' think twice about it). Nonetheelss, there are a few things to be aware of: 1.) Your I/O update will increase. There can be only one DP Master active at any given time and let's say your MP1, 2 and 3 PLC's (the DP masters) all have roughly the same number of DP Slaveseach, this is what happens on the bus: MP1 PLC will poll its DP Slaves, then pass the token over to MP2 PLC who will poll its DP Slaves and then pass the token over to MP3 PLC who will poll its DP Slaves before handing the token back to MP1 PLC. The result: Your I/O update time for each PLC issome three times longer in this example than it would be if each PLC had its own Profibus Network. 2.) Pay heed to the advise in Failure of a master in a multimaster system(truth be told, active termination is generallygood Profibus Network design practice). 3.) In case your three PLC's are NOT in the same S7 project, change the Profibus profile in each project to "Standard" (double click on the Profibus in HWconfig, click on the "Properties" button and go to the "Network Settings" tab). Therafter, click on the "Options" buttonand include the other DP Masters and DP Slaves in the "Network Stations" tab. 4.) Your sketch mentions a "Redundant fibre" link between the two OLM's. If so, please pay heed to what the OLM manual has to say about this special case and also use the "Cables" tab (also in "Options" popup of the Profibus properties) tospecify the number of OLM's and that an Optical Ringis used That's all I can think of and I hope helps |
Cheers |
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