Sam, As far as the 1pps is concerned, it is only 1 microsecond in width. So, I doubt you are going to see it on the LED without a pulse stretcher as that is too fast for your eyes. Use a one shot to lengthen the pulse to at least 1/2 second.
The RS-232 is used to command very small frequency adjustments to the Rb. However, to see any return information you must command it to tell you something. If you need a reference manual on it let me know and I will send it. Bill....WB6BNQ Sam Reaves wrote: > Hello Group, > > I just bought four of the FE5680A's that have the standard configuration > Pin 1+15, Pin 2 Gnd, Pin 3 Lock, Pin 4 +5V Pin 5 Gnd, Pin 6 1pps?, Pin 7 > 10MHz, Pin 8 TX, Pin 9 RX. > > I have a LED with a 330 ohm current limiting resistor on pin 3 (the > 74ACT240 can sink up to 24mA and I am well below that) for the lock > indicator. All of my units lock and produce 10MHz although the 1pps never > switches. > > I can not get any of the units to communicate using the DB-9 connections. I > scoped the receive data into the unit all the way to the microcontroller. > The RS232 and TTL levels for the data look perfect as well as the timing > for 9600-N-8-1. However the unit never transmits any data.I scoped this all > the way to the micro as well. Not a pulse spike or anything. > > Has anyone determined what the second serial interface is for? It seems to > me that it would not make any sense for FE to install the RS232 port if it > could not be used. > > Any hints? > > Thanks > Sam > W3OHM > _______________________________________________ > 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.