Windows Serial Device Driver
This driver is 100% Serial.Sys compatible, all your normal serial communications software will work normally.
Our driver adds support for 9-bit protocol (Multidrop) - simply set the parity to PARITY_MULTIDROP and all messages will be sent 9-bit style. RTS line is used to turn on/off your transceiver - it even has a 5 ms delay after turning on to allow transceivers to settle before the first character is sent. RTS line turns off exactly when the last character in a message goes out to allow a slave node to respond. Use WriteFile to send a message, use ReadFile to retrieve a response.
Is your Serial Network somewhat special? We'll add your requirements to our device driver for you!