Please show us more details, like: - kernel messages how the devices attach - maybe kernel messages from somewhere else (FreeBSD?)
You can use ktrace on the daemon process to see the communication it does via the serial device. First important part: which device node is it opening? E.g. it could be using /dev/ttyU0 instead of /dev/dtyU0 and block on missing "carrier" or something (but details depend on what the program wants to do and how the device behaves). Maybe the tty settings have not been ported to NetBSD properly. Martin
