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Serial Card and 6-digit Modbus Address

Serial Card and 6-digit Modbus Address

DeltaV Serial Card displays 5-digit Modbus address that can be configured as master to read from a device slave. How do I make it read a 6-digit Modbus register of a slave device? Does serial even support this format of Modbus addresses? What alternative can be explored for DeltaV to read a 6-digit format Modbus registers?

Wole Adekunle

• 25 Dec 2024 3:09 PM
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1 Reply

• Matt Forbis

  

  • 2 Jan 2025 5:20 PM

  5 and 6 digit addresses are equivalent up to the first 9999 registers. For example, 40001 = 400001 because the way to think about modbus registers is really Type + Offset. Type 4 = Holding Register for example, offset = 1 in my example. That being said, if you need addresses beyond the 10000 of a particular register type, Emerson does have custom serial card firmware that can be ordered that will allow access to the extended modbus registers. You change the card to a programmable serial card and flash the firmware after you have ordered it from Emerson. (I believe the part number is IOD-1134). If using a VIM, the firmware supports it and starting in v15.FP2, extended addresses can be configured directly for the EIOC and PK controller.

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