The information you need is more in the description of the software commands, this will tell you how to switch between the internal and external oscillators and how to vary the conditioning parameters and I'm pretty sure, although it's been a while so might be wrong, that some of the software contains menus to make this more straightforward. As long as what you have has already been configured as a BC637, ie existing firmware is aware that the GPS module is fitted, then there's no further change required to attach an external oscillator, as per above all the commands to do this are already available. In manual version K see page 6-4 and 6-15 for info on command 0x25, set disciplining gain. See page 3-6 section 3-5 on Hardware Menu option in the software.... keep on reading the manuals:-) Regards Nigel GM8PZR
In a message dated 07/02/2014 18:06:55 GMT Standard Time, t...@patoka.org writes: Thanks everybody for the bit of information ! I have a "Revsion C" and "Revision K" manuals. In Revison "K" its only one note about OCXO: "An internal 10 MHz VCXO (Voltage Controlled Crystal Oscillator) is disciplined to the reference source. The VCXO output drives all timing functions on the card. The VCXO output and a 1pps signal are provided as outputs. The TFP is also capable of disciplining an external voltage controlled oscillator. As an option, the TFP board can be ordered with an OCXO (Oven Controlled Crystal Oscillator) installed." As far as I understood, if I'll implement external OCXO to my BC637, I'll need to change FW on the card to make it work. If so, its not an option for me, since I just bought that card from auction and there is no way to obtain new microcode for it. Off-topic: Aside of that OCXO implementation, I would like to ask some direction from time-nuts community about the relatively simple way to compare two 1PPS signals using some MCU. Lets say I have T-Bolt and BC637. Each has 1PPS and I would like to see the phase difference between of that two. Of course it is some instruments already available for that, but I have not own that one (yet). I am thinking to connect both 1PPS to Timers input in "capture" mode on MCU. Then register first raising edge, start counting of ticks until second timer will not catch another signal raise. Then number of ticks will indicate the difference. But may be it is more "elegant" way to do that comparison ? Thanks ! Regards, V.P. On 2014-02-07 03:38, gandal...@aol.com wrote: > I played with this around five or six years ago but unfortunately my > notes > from that time are likely to be buried somewhere still waiting to be > scanned or indexed. > > All the necessary information though is in the user and SDK manuals, > connections for the 10MHz external input and EFC output are on the 15 > way I/O > connector and there's even demo software which I'm pretty sure was all > I used > to make the necessary adjustments. > One manual, pre Symmetricom, even has what looks to be a full set of > schematics. > > I've just run the software again to check but it won't do much if it > can't > find the card so would need to fire up another PC with a spare slot to > check further. > > I wasn't really happy at the time with my attempts to condition an > external Vectron OCXO, it was certainly better than using the > internal oscillator > but there were some odd jumps and drifts using either which suggested > these > might be artifacts of the board itself rather than the Vectron OCXO. > > I've since acquired another BC637PCI, and want to try both again with > other oscillators, but that's quite some way down a very long to do > list, now > reminded though I might take a quick look later:-) > > In the meantime, I have got copies of manuals and software etc and > will > get those zipped up today and make them available for download. > > Regards > > Nigel > GM8PZR > > > > > > > > > > In a message dated 07/02/2014 03:36:46 GMT Standard Time, > t...@patoka.org > writes: > > > Hello, > > Does anybody seen any links to the information how to implement > external > OCXO to Symmetricom PCI TFP BC635/BC637 ? > > > -- > WBW, > > V.P. > _______________________________________________ > 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. -- WBW, V.P. _______________________________________________ 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.