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SOLVED - CP342-5 to CPU315-2 DP communication

Created by: mrfusion at: 10/6/2014 5:26 PM (2 Replies)

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10/6/2014 5:26 PM	Rate (0)
mrfusion Member Joined: 6/26/2014 Last visit: 1/13/2020 Posts: 13 Rating: (1)	Hi all, I am trying to communicate a CP342-5 (342-5DA03-0XE0) as a master to a CPU315-2 DP (315-2AH14-0AB0) as an i-slave. The two are linked via a profibus cable that I have tested to work fine on another setup, with terminating resistors ON. The i-slave has 4-byte input and output areas declared as:- Transfer Area \| Master add \| Slave add \| length \| consistency WR \| Q1000-1003 \| I2000-2003 \| 4 byte \| total length RD \| I2000-2003 \| Q1000-1003 \| 4 byte \| total length The CP342-5 is connected to another CPU315-2 DP to control it via the rack backplane bus, whose profibus connection is already in use. I am trying to setup the DP_SEND and DP_RECV blocks to communicate with the i-slave. Now.. this is where I am stuck. How do I specify the CPLADD on each block, simply as "320" or does it have to be in hex e.g W#16#140, or is either acceptable? Also, I have specified the SEND parameter on DP_SEND as P#DB4.DBX0.0 BYTE 4, however I do not know what parts of that data in the DB specify the i-slave transfer area address. What information need to be in the SEND parameter to send anything to the i-slave? Finally. the bus fault LED is flashing on the CP342-5. Am I guessing correctly that this is because I have not specified FC1 and FC2 in my program to actually initiate any data transfer, hence there is no bus activity and so the BUSF LED is flashing? Thanks in advance.
	Last edited by: furutsun at: 10/9/2014 1:08 PM Last edited by: furutsun at: 10/6/2014 5:27 PM Last edited by: furutsun at: 10/6/2014 5:26 PM
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10/6/2014 7:40 PM	Rate (0)
hdhosseini Diamond Member Joined: 1/28/2009 Last visit: 6/1/2023 Posts: 6803 Rating: (1345)	furutsun Hi all, I am trying to communicate a CP342-5 (342-5DA03-0XE0) as a master to a CPU315-2 DP (315-2AH14-0AB0) as an i-slave. The two are linked via a profibus cable that I have tested to work fine on another setup, with terminating resistors ON. The i-slave has 4-byte input and output areas declared as:- Transfer Area \| Master add \| Slave add \| length \| consistency WR \| Q1000-1003 \| I2000-2003 \| 4 byte \| total length RD \| I2000-2003 \| Q1000-1003 \| 4 byte \| total length The CP342-5 is connected to another CPU315-2 DP to control it via the rack backplane bus, whose profibus connection is already in use. I am trying to setup the DP_SEND and DP_RECV blocks to communicate with the i-slave. Now.. this is where I am stuck. How do I specify the CPLADD on each block, simply as "320" or does it have to be in hex e.g W#16#140, or is either acceptable? Also, I have specified the SEND parameter on DP_SEND as P#DB4.DBX0.0 BYTE 4, however I do not know what parts of that data in the DB specify the i-slave transfer area address. What information need to be in the SEND parameter to send anything to the i-slave? Finally. the bus fault LED is flashing on the CP342-5. Am I guessing correctly that this is because I have not specified FC1 and FC2 in my program to actually initiate any data transfer, hence there is no bus activity and so the BUSF LED is flashing? Thanks in advance. Hello, Answers to all your question can be answered here: How do you configure an S7-300 CPU as DP slave to a CP 342-5 as DP master? and some brief answers: CPLADDR should be in HEX format Write 4 bytes from master via "DP_SEND" via CP345-5 through PROFIBUS network and read them by SFC14 in I-slave. ANY pointer ,in both functions, indicates the DB number, point of start and width of data area. Test the whole test set-up with the finalized project with the program in both CPUs. Please find more projects here: What master/slave communication options are available on PROFIBUS DP? I hope this helps, Hamid Hosseini
	Demo Channel on Youtube
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10/9/2014 1:07 PM	Rate (0)
mrfusion Member Joined: 6/26/2014 Last visit: 1/13/2020 Posts: 13 Rating: (1)	Thanks, I've got this working finally. The crucial piece of information was that the CP342-5 reads data from the slaves on it's network from address 0 sequentially for the amount of bytes you specify by the BYTE X part of the DB declaration accross all slaves, and providing the slaves have consecutive stransfer area address. In this case for a CPU it is good to set the tranfer area addresses from address 0 for the previous reason, else if the transfer area address starts at 1000, you have to read 1000+ bytes into your DB before you get the data you want. Hopefully this can help anyone also starting out.

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