Thanks for all your suggestions! Ends up that I seem to have found yet a different version of the 5680a :) My DDS board did have an RS232 level shifter but for some reason, the RS232 TX signal was not being brought out to the 5 pin connector. Once I soldered the TX wire directly to the SP233ACT level shifter (pin 5), I was able to communicate with the device.
Thanks, James Date: Sun, 09 Dec 2012 23:25:25 -0800 > From: Hal Murray <hmur...@megapathdsl.net> > To: Discussion of precise time and frequency measurement > <time-nuts@febo.com> > Subject: Re: [time-nuts] FE-5680A OSMT connector / RS232 > Message-ID: > <20121210072525.7b0ef800...@ip-64-139-1-69.sjc.megapath.net> > Content-Type: text/plain; charset=us-ascii > > > ja...@peroulas.com said: > > I'm not able to get it to respond to the 'S' command and when I measure > the > > voltage on the RS232 TX pin (#2 from the left) it's always 0v. Shouldn't > it > > be -12v when idle? > > Newer RS-232 allows 6V rather than 12. > > In practice, it's not all that uncommon for designers to save a chip and > just > send 5V CMOS signals. That works fine for short distances. > > If you can get a scope on it, sometimes embedded boxes send out a hello > message at power up. > > I'd also check pin 3 in case you or they got things swapped. > > > -- > These are my opinions. I hate spam. > -- *Integrity is a binary state - either you have it or you don’t.* - John Doerr _______________________________________________ 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.
