> The good output +/-9V or more as the spec requires. According to the official RS232C specifications, the valid voltage range must be between +/-3V and +/-15V (+/-25V for the first draft). A device that absolutly require +/-9V is not RS232 compliant. BTW, as you said, some cheap USB<->Serial adapters output 0/+5V TTL levels and don't work with many devices.
-----Message d'origine----- De : time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] De la part de Poul-Henning Kamp Envoyé : vendredi 20 février 2009 20:55 À : Discussion of precise time and frequency measurement Objet : Re: [time-nuts] Does the Thunderbolt have to be connected to a real serial port? In message <499f09e5.4020...@xs4all.nl>, "S. Nestra" writes: Quite a lot of USB-serial adapters cheat at various levels. The worst output 0/+5V or +/-2.5V either of which are totally outside the spec at the receiving end. The acceptable output +/-5V, which i out of spec for a transmitter, but inside spec for a receiver, so a short or no cable, it works fine. The good output +/-9V or more as the spec requires. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
