Calculating modbus RTU 3.5 character time

Question

am new to Modbus and developing an application using Modbus RTU. I would like to know how to find out the RTU message frame separation time. In the Modbus RTU specification, It

Answer 1

Modbus RTU use 11-bit char, regardless using parity or not. The formula should be : 11 * 1000000 / ( baud_rate ) for one char time, this applies for baud rate <= 19200 bps. For baud rate > 19200 bps, fixed time is used, which are 1750 micro seconds for 3.5 char time, and 750 micro seconds for 1.5 char time