Modbus help to read messages – General

Hi all, I’m new in modbus protocol communication and I would ask few questions.

I have a slave and an excel with a table of registers, quantities and description and I would understant how to receive the data in correct format from slave. I can connect to the slave until now and I receive datas but I have many difficulties to undestand the meaning of messages.

For example for the registers with dimension 1 I use the following code:

with function:

msg.payload = {
‘fc’: 3,
‘unitid’: 1,
‘address’: 4,
‘quantity’: 1
}
return msg;

and I receive the temperature as integer number and not float number.

then I would ask how to receive registers with quantities 2 or more and composed by msl and lsb words.
Can some one help me to undestant how to read correctly the different addresses with dimension 1 or more and composed by msl and lsb words?
many thanks in advance

Source link