Modbus RTU Address

[Costi_s]

Hi everyone,

I'm working with modbus rtu and i need to set up a connection with a master.
In my specifications the master should read from my slave a certain PDU to be xxxx.
For example, PDU2000 should be 4600, Read Holding Register, U16

How can i convert this PDU2000 to an address register such as 40001?

Thanks everyone in advance.

[K C]

Hi,

Always confusing, the DCS way of defining ModBus registers.

A notation like 40001 tells that you have to use function code 3 (or 4 in most cases) and read address 0.

So the first figure is the command code (Read Holding register) and the last part is the ModBus address but 1 higher as the real ModBus address.

Kees