I am trying to develop a c++ program for acting as a Modbus master (for data acquisition from power meter which works on Modbus RTU protocol) for my project work. The Modbus RTU protocol says that the query to slave must be framed i.e. succeeded and preceeded by 3 and half character elapse. I don't understand what it actually means, and how can it be achieved through c++ program. Please help me out.