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A forum for topics related to the scope of Modicon PAC offers and ecosystem along the whole lifecycle: Modicon M580 and 340, EcoStruxure Control Expert, EcoStruxure Process Expert (Unity Pro) and more.
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Posted: 2025-09-05 08:54 AM
Hello,
I am looking to get some clarity on what the "Offset/Device" field specifies when configuring Modbus TCP/IP communications through the DTM Browser/IO Device Editor (windows shows: "fdtConfiguration").
It appears that the Offset/Device does not line up with the RD Address/RD Length, but instead just increments to the next multiple of 8 available. In the manual, the only reference I can find states that both Offset/Device and Offset/Connection represent the byte address, however this does not appear to be the case.
Thank you!
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Posted: 2025-09-08 09:34 PM
Had you created other transactions and then modified or deleted these?
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Posted: 2025-09-09 07:19 AM
That is possible as there were many hands involved in development. Are you saying that ControlExpert would auto-index the 'offset/device' field, and then further modifications to the device (removing entire requests, updating RD addresses, etc) could potentially cause items to de-sync?
I may try removing/re-creating the mapping to see if the offsets change.
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