Hi Shashank Hope you are still around and you manged to implement you modbus as I am just embarking on the same course. I am using a PIC24F and need to implement RTU. I want to know how to implimented the character recieve and transmit timings required in modbus from within FreeRtos. I assume, for the RX, it is a matter of notifying the RX task from the UART rx interrupt and looking at time passed since last recieved. If you could share the RTOS level code to do this I would be very greatfull. Thanks Mark