Hello, thanks you a lot for the documents you shared with me. I apologize for not having replied before. I read all documents and I got the conclusion that to improve the data transfer performance the user application should transfer through USB interface the biggest quantity of data at once, the latency timer should be set in a big value so this one does not interrupt the transferring, the USB IN and OUT request sizes should be set to big values and, ideally, the number of bytes requested by the user application should be an integer multiple of the number of data bytes in an USB IN transfer request.
I followed those rules but, painfully, I did not get good results, the application got frozen when I tried to read a lot of data at once. So, I decided to set up the FTDI chip following the recommendations for data transferring of small numbers of bytes, i.e. I set up the latency timer in the smallest value, 2 ms, and I modified the user application to request small number of bytes at once. And I got a little bit performance improvement with that configuration.
On the other hand, I analyzed the data transfer rate of the RS232 interface and I realized the maximum baud rate is 921600 bits/s (taking into account the constants defined in the header file ftd2xx.h) which is much smaller than the typical baud rates which are offered by the USB interface. Can I use a bigger baud rate of the RS232 interface? Will that produce data missing, taking into account I am not using flow data control?