Uwe Klein wrote: > I will have to read up if the usb2serial ics have some kind of fifo > included ( and enabled or not ). This could be an explanation.
The basic problem with serial to USB converters is that the serial lines basically use transmission of characters whereas USB transmission is block-oriented. If a converter receives one character from the serial side it either can put that single character into an USB block and send that block immediately, which generates much overhead but low latency, or it could wait for a certain interval whether additional characters arrive, which could be packed together and sent in a single USB block. A new USB block is sent if either enough serial characters have arrived, or no characters are arriving anymore and a timeout occurs. The latter is good for USB throughput but generates a latency up to the timeout limit. So the behaviour should depend on the implementation of an individual converter type. BTW, similar problems arise with serial-to-LAN converters which redirect a serial data stream using IP packets. Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
