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| 1/14/2010 1:25 PM | |
Joined: 9/27/2006 Last visit: 3/14/2025 Posts: 12344 Rating:
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Hello jey; When you want to connect 2 CPUs through Profibus, you can have 2 basic setups: 1) One is DP-master, the other is DP-slave; Since the DP ports on the CPU cannot act at the same time as master and as slave, this means that at least the one selected as slave cannot have its own slaves on that port. If this is the configuration you choose, look at the following FAQ showing an example on how to set the S7-400 as master and the S7-300 as slave. Once you get the wxample working, you wil;l need to adjust the number and size of modules to firt your application. SFC 14 and SFC15 are not necessary un;ess you want "consistency" in your communications (look the term up on this forum, for example). http://support.automation.siemens.com/WW/view/en/6518822 2) Both CPUs have their own slaves, and therefore cannot be setup as slaves. In this case, youcan use a DP/DP coupler, since it can be configured as a slave on both CPUs, and exchange data up to 244 bytes between the 2 masters. There are other ways to do this type of master-to-master exchanges (look up "FDL" on the forum) but they require more programming and can only be used if you have communication processors (CPs) for Profibus-DP on your racks,So the DP/DP coupler is a cheaper and faster way of doing this. Hope this helps, Daniel Chartier |
| 1/14/2010 2:43 PM | |
Joined: 8/25/2005 Last visit: 1/29/2025 Posts: 1162 Rating:
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Hello jey@tokyo, There is another possibilityI think. You could use the S7 Communication. Programming the SFC PUT and GET within the S7-400 to read or write date from / on S7-300 Here you could find a example S7-400 to S7-300 via CP's SIMATIC net Quick Start Good luck Sabine |
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