what is the holding registers address

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Luke H asked May 26, '20 Matt Long answered May 28, '20

what is the holding registers address

emulation properties.PNGim tryna connect an arduino uno as modbus master to my flexsim model which is the modbus slave via a RTU (serial connection) and when programming by arduino it says Modbus holding registers are from ox40001 and up but on flexsim it says registers go from 0-9999 so wondering how these flexsim registers worked in relation to standard modbus registers. does this mean register 1 is ox40001?

Software Version:

FlexSim 20.1.2

flexsim 20.1.2 emulation modbus communication rtu

emulation-properties.png (24.7 KiB)

Answer 1 · 2020-05-28T12:01:11Z

Matt Long answered May 28, '20

Modbus registers in FlexSim are defined from 0-9999 where each register type, Coil, Discrete Input, Input Register and Holding Register is written using these 4 digit addresses. For Input Registers, an address of 1 would refer to address 40001.

This is pretty old code and should be updated to use the latest modbus specification. I'll add this to the dev list to change in a future release. Thanks!

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