I have implemented a new serial data transfer protocol in our 8051 system (80C552). I tryed to write the received characters immediately back to the terminal with the following commands:
ucrs232_buffer[ucrec_count] = S0BUF; S0BUF = ucrs232_buffer[ucrec_count];
Thank you for your message and the baud rate generator. I tryed the baud rate 1200 with and error of +0,17% and I got the same result! Unfortunatly it was not the reason! Christian