6/14/2020 10:39 AM | |
Joined: 12/28/2016 Last visit: 12/22/2023 Posts: 364 Rating: (6) |
because of some reason I am unable to see the slave in my list |
With kind regards... |
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6/14/2020 11:21 AM | |
Joined: 12/28/2016 Last visit: 12/22/2023 Posts: 364 Rating: (6) |
No hardware ID |
With kind regards... |
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6/17/2020 3:28 PM | |
Joined: 9/27/2006 Last visit: 4/19/2024 Posts: 12256 Rating: (2664) |
Helloqwemx; Why do you complicate your life so? As stated before, Profibus masters and slaves (as long as they are certified) work the same way whatever manufacturer produces them. So Profibus functions such as DPRD_DAT and DPWR_DAT (functions that work on a S7 DP master) will read and write consistent data to/from a configured DP slave. Proof? Open the pdf file provided by Grzeg0rgzG in the following discussion, read the section on Access to Process Data. The document was written by Wago engineers. https://support.industry.siemens.com/tf//ww/en/posts/wago-and-step7/23236/?page=0&pageSize=10 Hope this helps, Daniel Chartier Edit: S7 Communications work on any native network (Profibus, Profinet, Industrial Ethernet) by which 2 S7 PLCs are connected. Your understanding of the examples is wrong. |
Last edited by: dchartier at: 06/17/2020 15:31:22Last edited by: dchartier at: 06/17/2020 15:32:34 |
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6/17/2020 5:10 PM | |
Joined: 12/28/2016 Last visit: 12/22/2023 Posts: 364 Rating: (6) |
Hello dchartier Actually I think I was not able to express it clearly - but here is what I understood whenever a slave and a master are defined in Step 7 software then the slave will be assigned Input and output areas these will have a starting address for example in the attached screenshot the slave has starting address of 160 for both input and output area . When we use DPRD_DAT and DPWR_DAT we are ONLY able to write to these addresses and read from these addresses .(160 as in screenshot) so when we are reading from the slave we tell DPRD_DAT to start reading from the start address of 160 (entered in hex) and we know how many bytes will be read so we assign an address in the plc memory where it can copy the read data and same for Write ... so DPRD_DAT and DPWR_DAT is only limited to these areas it can not write/Read() directly from a DB in a PLC (master) to another PLC(slave) i can however use these areas and then transfer to DBs I was thinking if it is possible to access any area and pass the address of DBs and then read and write but it seems it is limited to the Master slave assignment areas in a master slave system |
Last edited by: qwemx at: 06/17/2020 17:30:25Last edited by: qwemx at: 06/17/2020 18:07:21With kind regards... |
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