Hi Bob I view the master/slave situation the same way you do, but only commented because Lucent effectively sets things up the other way round so just wanted to be sure which way Paul was considering it. As regards, the "faking", yes, a single 15 way plug containing just a link and a resistor is exactly what I use now. I realise the RS422 fudge isn't ideal but certainly very handy for some quick tests. I've got two or three RS422 PCI interfaces but hadn't previously had any spare slots, now I've got a couple of lovely Magma 13 way PCI expansion units but need to hack them about so the ports are at the front. Whoever decided rack mount PC kit should be built with all the connections at the rear must have been really nuts, and it was too long ago to use "corridors" of racks as a viable excuse, someone somewhere just fitted ears to desk top style cases and left the rest of us to get on with it.. One of the best things I ever did was to buy a pair of "back to front" rackmount PC cases with all ports and cards available at the front, trouble is now I want everything else to match, and most test gear has just the same issues! All good fun, and certainly never a dull moment:-) Regards Nigel GM8PZR In a message dated 06/11/2014 12:04:47 GMT Standard Time, [email protected] writes:
Hi > On Nov 6, 2014, at 3:44 AM, GandalfG8--- via time-nuts <[email protected]> wrote: > > Hi Paul > > Prime question is what are you calling the "slave" unit? 1) Slave in the sense that it’s slaved to the GPS in the other box. Unless we find a serial link from the Ref-0 back into the Ref-1, that’s all it’s doing. 2) It fires up and the Ref-1 box gets all organized and locked up. It goes “ok” first, then the Ref-0 goes “ok” (locks to GPS). In that sense, the Ref-1 is the master. My guess is that they default to output from the Ref-0 rather than Ref-1 because it’s the one more likely to fail (more single points to go wrong). > In normal use Lucent treats the Ref-0 unit as the master and Ref-1 as the > slave, but it's Ref-1 that contains the GPS module. Bit confusing Yes it is confusing - sorry about that > but if > you've got Ref-1 with the GPS module then you're in business:-) > > It's turned out the transistor delay circuit isn't needed after all and the > wiring can be simplified too. > > All that's necessary to run the Ref-1 stand alone is to ground pins 2 and 3 > on the J5 interface connector and there's a couple of convenient ground > pins already on that connector, 8 and 13. > In normal use pin3 is tied hard to ground, presumably via direct link from > the other module, so that can just be a wire link to either pin 8 or 13. > Pin 2 is normally held at a logic low level so although a direct ground > seems to work ok for that too, and no damage noted so far, I prefer to play > it safe and ground that one to the other ground pin via a 470ohm resistor, > which also works fine. > That's it. So a single 15 pin connector with one jumper and one resistor (or jumper) plugged into the interface socket. > > The LEDS should flash at start up, followed by "No GPS" and "Fault" on > solid whilst the unit goes through acquisition and lock, this can take an hour > or so, and then those LEDs should go off and the "On" light should be > solid. > At this point the 15MHz and 1PPS outputs are enabled. > > The J8 diagnostics connector is enabled from start up and SatStat can be > used to monitor progress. > The RS422 3 wire fudge suggested by Stu Cobb works fine for me, J8 pin 7 to > PC 9 way comm port pin 5, J8 pin 8 to comm port pin 3, J8 pin 9 to comm > port pin 2. Works, but if you have an old style +/- 12 V RS-232 signal, things might or might not work forever. A lot depends on how they have protected the chips. They expect a 1.5 to 3.5V signal on the input, so even +/-5 is a bit exciting. Full blown RS-422 interfaces are sub $15 gizmos. Bob > > Regards > > Nigel > GM8PZR > > > > In a message dated 06/11/2014 01:24:33 GMT Standard Time, > [email protected] writes: > > I have been following the threads on the KS-24361 some of the longest I > have ever seen on time nuts. > So I have a very basic question. > There was a 2 transistor delay circuit by Arthur way back. I believe this > is needed. > But then the pin numbers seem to get a bit mixed up and there are some > jumpers with several comments. > Is there a clear guidance on what to do? I do not have the slave unit. > Power is not an issue. > Thanks in advance for your help. > Must say the units very nice. > > Regards > Paul > WB8TSL > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
