On Mon, Feb 18, 2019 at 09:24:33AM +0100, Martin Husemann wrote: > Note that your FreeBSD installation writes something completely different > to the device.
It has been pointed out off list that the FreeBSD ascii version is just differently encoded (with "." for unprintable character), and the packet written is actually identical. So I have no idea why the device answers differently (and no idea how to debug this unless the device itself offers some debug options). Martin
