Hal Thanks for your kind help. You are certainly right about the PECL level signals from the I/O connector, but this is where the similarity stops, as the Trimble unit is to all intents a substitute for the Z3801A, but internally its quite different. In the interests of costs, it would seem that there is no RS-232 facility. There is a sub PCB that carries the LED's at the front of the unit via a connector, and there is a location on this PCB for a for a 9-pin D connector!. If this had been used it would have made a serial port available at the front panel. More interesting is that there are tracks feeding what would have been pins 2,3 and 5 ! Perhaps there was an intention in the original specification to provide a "service" serial port to the front of the unit - but would this have provided RS-422 and not RS-232 signals ? Unfortunately, Trimble will not offer any information on this unit, as it was made for Nortel, and I have so far not been able to find any alternative information except for a brief reference in the Z3801A article.
Roy ----- Original Message ----- From: "Hal Murray" <[EMAIL PROTECTED]> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Saturday, November 22, 2008 6:27 AM Subject: Re: [time-nuts] The Trimble NTPX26AB-06 / Z3801A > >> On the Z3801a, if you want to use the 1-PPS or 10MHz signals that are >> on the DB-25 you will need to convert the PECL outputs. > > If you are willing to lift a pin and cut a trace, you can get the PPS on > RS-232 without any external level conversion. The fine print is in here: > http://support.ntp.org/bin/view/Support/Z3801AReceiverModifications > > I used a non-standard pin on the DB-25 in order to avoid cutting a trace, > but > I was building my own 25 to 9 pin adapter so that was easy fix. > > > > -- > These are my opinions, not necessarily my employer's. I hate spam. > > > > > _______________________________________________ > 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.
