3/18/2021 2:35 PM | |
Joined: 9/27/2006 Last visit: 8/7/2024 Posts: 12273 Rating: (2680) |
Hello; What protocol are we talking about, on the CP 341? Hope this helps, Daniel Chartier |
3/18/2021 2:38 PM | |
Joined: 12/7/2020 Last visit: 2/9/2022 Posts: 9 Rating: (0) |
Modbus RTU |
3/18/2021 2:54 PM | |
Joined: 3/5/2014 Last visit: 8/5/2022 Posts: 5521 Rating: (1054)
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hi, Modbus RTU is a communication between a MB Master and MB Slaves. you need to define the interface(CP341) as master or slave depending on how your communication partner is doing it. If your communication-partner is working as slave, you need to be the master and vice versa. Here you can find a application sample for better understanding: Master-Slave Communication with Modbus RTU for S7-300 and ET 200S Systemshope this helps, regards, |
FCK WAR! |
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3/18/2021 3:04 PM | |
Joined: 9/27/2006 Last visit: 8/7/2024 Posts: 12273 Rating: (2680) |
Hello; For a Modbus RTU installation on a CP 341, using the Loadable driver from Siemens, the most difficult aspect (in my experience) is in the commissioning of the driver, when you have to convert the Modbus addresses to Siemens DBs. Holding registers in Modbus start at address 30001, which a Siemens CPU does not understand. You must tell the driver which base (initial) DB will correspond to this 300001 Modbus address (and the following registers), and conversively, you must be able how to determine which DB register address corresponds to the Modbus address requested by the master: Have a look at these pages from the Loadable driver Modbus RTU slave manual (of course the complete manual should be useful in your project): https://support.industry.siemens.com/cs/ww/en/view/1218007/13407330571 https://support.industry.siemens.com/cs/ww/en/view/1218007/13407701003 (conversion formula) Hope this helps, Daniel Chartier |
Last edited by: dchartier at: 03/18/2021 15:06:42 |
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3/18/2021 3:08 PM | |
Joined: 12/7/2020 Last visit: 2/9/2022 Posts: 9 Rating: (0) |
Thia Application have only for ModbusMaster mode for CP341.. |
3/18/2021 3:09 PM | |
Joined: 4/28/2015 Last visit: 2/7/2024 Posts: 10533 Rating: (819)
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Hello,
generally you're provide same system of data on other side than Master. You need have defined areas as Holding register or Input register and also provide other I/O data, same as Master can require. You need check documentation to specific driver (in this case Slave) and prepare all what you expect to give to Master. Manual: Modbus RTU Slave driver Manual S7-300/400 |
Last edited by: Duris_I at: 03/18/2021 15:11:15With best regards... |
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3/18/2021 3:14 PM | |
Joined: 12/7/2020 Last visit: 2/9/2022 Posts: 9 Rating: (0) |
I also will suggest using the initialization module MODB_341 and configure HW like picture....for Slave mode it is enough ? |
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