When communicating with the Robovero over a serial connection (through the mini USB port), how fast can the commands be processed?

From a C program, I've opened a serial connection and initialized the robovero with the following commands:

1. \n (new line for robovero to detect line termination)

2. promptOff

3. resetConfig

4. roboveroConfig

5. configure and control PWM


If I send these commands to fast, some of them aren't processed by the robovero.  Waiting for the serial device to finish sending the data ( tcdrain() ) prior to sending the next command helps a little bit, but I've noticed there are still occasions where the command is 'dropped'.

What's the right frequency to send commands to the robovero, such that no commands are dropped?

Thanks,
Andrew