Set the time to wait after dropping DTR to the given number. The units are hundredths of a second. The default is 300 hundredths, i.e., 3 seconds. This option needed mainly to set proper recover time after modem reset.
drainwait number
Set the time to wait for output drain to the given number. The units are seconds. The default is 5 minutes, 0 means waiting forever. This option needed mainly to specify upper limit of minutes to prevent modem hanging.
The standard way to use comcontrol is to put invocations of it in the /etc/rc.d/serial startup script.