xntpd with external DCF77 receiver problem (/dev/cua00)

I’m trying to install the xntpd3-5.93e-export package on a
OpenBSD 2.7 (i386) system, using a external time receiver
Expert mouseCLOCK using the DCF77 Clock from
[http://www.gudeads.kud.com/emc-e.htm .

I’ve configured it with the –enable-RAWDCF option and
connected the external time receiver on the serial port 0.

I tried /dev/cua00 and /dev/cua01 and I get the following
message :

Nov 10 17:18:41 hostname xntpd[pid]: xntpd 3-5.93e Sat Nov 10 17:13:31 CET
2000 (1)
Nov 10 17:18:41 hostname xntpd[pid]: tickadj = 40, tick = 10000,
tvu_maxslew = 3960, est. hz = 100
Nov 10 17:18:41 hostname xntpd[pid]: fcntl(F_SETOWN) fails for clock I/O:
Inappropriate ioctl for device
Nov 10 17:18:41 hostname xntpd[pid]: PARSE receiver #0: parse_start:
addclock /dev/refclock-0 fails (ABORT – clock type requires async io)
Nov 10 17:18:41 hostname xntpd[pid]: configuration of 127.127.8.0 failed

I’m a bit stuck, reading the documentation for xntpd doesn’t give me a clue
on how to proceed right now. Any pointers ?

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