I want to design a modbus controller, and where can I find the IC which support modbus/rtu?

 

Sir
Unable to understand your question.
You mean... Separate IC for MODBUS communication?
If so, sorry, there is no such IC available in the market. The main Microcontroller will be connected to the RS485/RS232 hardware ICs (for RS485 it is 75176 and for RS232 it is MAX 232 like that) and the Tx and Rx lines from the controller will be connected to these ICs. Now the master (In our case let us assume it as a PLC which support MODBUS protocol) will be connected to this arrangement with the available communication type. Thus the master will send the query (Refer MODICON site for query details) and the slave (In this case it is our unit) will respond to the query and send the data.

 

I'm just putting the finishing touches up on a Modbus RTU/TCP unit using the Rabbit 3000 from "http://www.rabbitsemiconductor.com":http://www.rabbitsemiconductor.com . Most all of the small micros could pull off Modbus RTU though -- it isn't that complicated. Find the processor that meets your price range, and if you want to have it done soon, one that you know how to program for.

Alex Pavloff - [email protected]
Eason Technology -- www.eason.com