Hello,
I am aware of the Modbus address mapping:

I try to communicate with LOGO via MTP panel, which is programmed using TIA portal.

I have learned that for example AI1 address is defined in TIA as 3x300001

I need to learn how to call the VW addresses such as VW1 etc.

I suspect that it is something like 4x400001 but can´t be sure.

Mapping space range for VW is 0-850 and Mapping holding register space for that is between 1 to 425. 

Is there any appendix for interpreting the address spaces? In other words, I´d need an extension to the Modbus address spaces indicated in form 1x10000X, 3x30000X, 4x40000X. It would be very convenient and time saving as I must not find the right ones by trial and error.

It would be greatly appreciated if a such table for address space conversions would be found. Here I do mean the fixed ones rather than the wild ones.

Thanks,

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Split from modbus addresses maping.

Thank you,

The communication works well. And I have figured out how to call Analog Input readings from the LOGO 8.3. Those you will get by using 3x300001-3x300008 (or alike), addresses from the TIA side.

Previously I have used VM mapping with the logo to define the communication parameters between a panel and logo. In this case the communication protocol has been profinet.

However, the Modbus communication seems to be something mysterious, because there is plenty documentation of the modbus itself, and even a clear list of the modbus address space is given.

What I am missing is a one example for how to call a reading from VW0 and/ or VW10. I do not have possibility to test every register.. It takes too much time. I have noted also that requesting too many readings at same time will freeze the logo - and you will get no values - this is easy. 

Is there anyone who has successfully called a value from a logo VW addresses? What addresses you have been using?  Would you give/confirm what are the corresponding addresses from TIA point of view?

Thanks!