rs485 modbus Protocol

[rmrps]

Hi Friends
I am new to rs485 communication i want to know how to create rs485 modbus protocol using given register value for accessing information that is read data and write data i have baud rate is 115200 data is 7, parity even stop bit is 1 and register address is
for reading data register address is D174
for write data register address is M605 and M72
slave id is 3A

Please guide me to create Rs485 Modbus protocol using the above register value

 

[KlausST]

Hi,

the internet has plenty of information on modbus protocol.

Did you:
* read wikipeda and the given links
* search for basic modbus protocol documents
* search for video tutorials?

Start with drawing a flow chart.
Give related (links to) documents you used
You need to write the code on your own, at least try. Show us your code, so we can verify it.
What microcontroller, what language and what compiler do you use?

Klaus

 

[FvM]

You'll refer to the specifications MODBUS over Serial Line and MODBUS APPLICATION PROTOCOL, available at modbus.org.

Having only 7-Bit data means that you are restricted to ASCII serial mode.