Hey Giacinto, > 100ms between characters seems excessive. > In general there are the RTS/CTS on the serial line and on the virtual > serial over usb (supported by option and acm drivers) for this. > A stripped down RS232 with only TX/RX/GND could need some delay, but > it is very difficult to guess how much: in this case it would be > better to have it as a parameter. >
Allowing to change it with udev tags seems an option, while keeping the same default value for old RS232 modems. > Some modems require a different delay: between the last answer and the > following command, to have time to output some URCs in between. > At least for Cinterion modems, they don't output URCs between a > command and its response, so they must be given a chance. > The Cinterion ATC guides always specify 100ms, but it turns out that > 1-2ms are enough. > Please note that the send-delay is not the timeout in between AT commands; it's the timeout in between the characters of a given AT command; i.e. if running AT+GCAP?: "A" then 100ms, "T", then100ms, "+" then 100ms, "G" then 100ms .... -- Aleksander https://aleksander.es _______________________________________________ ModemManager-devel mailing list ModemManager-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel
