about modebus

i want to transfer the serial data using arduino mega 2560 with the help of modbus protocol.so plz give me the guidence about the required hardware and software....

Do you heard of a web service named “Google”? Just enter “modbus” and “arduino” in that service and it will show you valuable results.

but i am using arduino mega2560 and there is no lib for modbus so i want to know about how to create the lib ....so plz if you have it then it will be appreciable ....

but i am using arduino mega2560 and there is no lib for modbus so i want to know about how to create the lib ....so plz if you have it then it will be appreciable ....

Just take one example:

https://code.google.com/p/simple-modbus/

Where on that page did you find the information that it doesn't run on a Mega2560? So there is a lib for ModBus. If you need a special variant of ModBus you have to define that explicitly.

is ther any arduino board that support the in built library for modbus like mega 2560 is supporting SPI......if it is then tell me....

What "in built library" do you mean? What type of ModBus are we talking about?

What do you want to achieve? Your questions sound a bit wild and unrelated to me. What's your goal?

The mega will run just about everything the uno will plus lots more :wink: There is no built in library in the board thats in software and if you add a library now you can us it just like the ones that came with it.

I have been having lots of luck with the mudbus library yes “mudbus”

What is it going to be hooked to?

how the hmi and arduino communicate?... plz tell me .....

Ethernet is how do it. There is an e came in mudbus called Mb that shows you how it maps all of your coils and registers. Check out this post by GWManning @ http://forum.arduino.cc/index.php?topic=131915.0