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10/6/2013 3:52 PM | |
Joined: 9/27/2006 Last visit: 8/14/2024 Posts: 12277 Rating:
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Hello C.kt; The CP 443-5 Extended adds a Profibus DP master or slave to the CPU rack, when you need another Profibus-DP network in your project. Profibus-DP functionalities on the CP are equivalent to the integrated DP-interface, same number of slaves (on a master configuration), same size of data transfer per slave, same bus speeds. That being said, there is a big difference in the required programming for a Profibus-DP CP (CP 443-5 Extended for the S7-400, CP 342-5 for the S7-300) that often complicated the lives of the project programmer. When you download the Profibus-DP configuration for the CP (straight program blocks download to the CPU), the CP becomes an autonomous participant on its Profibus-DP network. It polls and collects data on its own. But to transfer that data to the CPU, you need to use specific functions ("DP_Send", "DP_Recieve") to exchange data with the CPU over the backplane. So you need toi understand how to program and configure the functions in order to use a Profibus-DP cP 443-5. You can have an introduction to these CPs in the following links: S7-CPs for PROFIBUS Configuring and Commissioning Functions To activate DP in the control program (Note: of the Profibus-DP CP), there are four functions (FCs) available, as follows: _ DP_SEND This block transfers the data of a specified DP output area to the PROFIBUS CP for output to the distributed I/Os. _ DP_RECV This block receives the processed data of the distributed I/Os and status information in a specified DP input area ._ DP_CTRL This block executes control functions for the distributed I/Os. _ DP_DIAG This block queries diagnostic data on the DP master and DP slaves. Also look at the contents of this FAQ ( it applies also to the CP 443-5) What are the differences between an integrated DP interface of my CPU (e.g. CPU 315-2 DP) and the DP interface of the CP 342-5? Hope this helps, Daniel Chartier |
Last edited by: dchartier at: 10/6/2013 3:54 PM |
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10/6/2013 4:54 PM | |
Posts: 139 Rating:
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Deardchartier, What about if i am using PCS7? In PCS7 we don't use the send and receive block via our own but may be @chart will be taken care of? below are the few points, i did research from CP manual. Correct me if i am wrong and also want to know what is the Integrated DP good for except cost saving? thanks in advance and may be i ask too much. Thanks for FAQ and link too. + Support CiR / HCiR + Constant Bus Cycles + Reduce the Load of CPU (20% reserve in HCPU) + Replacing a module without a PG devices + Forward Time / Sync Capability |
Last edited by: C.kt at: 10/6/2013 4:56 PM |
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