Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Steve My very small 10 cents. I am pretty sure win 95 had no idea what USB is. I think thats was win98 sp2 region. Certainly win10 wouldn't understand what that program was. But that said there are dos emulators/virtual machines that might let you get away with it. The other comment is if the device is circa 95 then most likely you will also have GPS week rollover issues. If the thing is selling for $1 then what the heck. Fun is fun. Otherwise you may want to consider something a bit newer saving the headaches and complexity. They seem to start in the $125 range and go up. There are certainly modern solutions at low cost without the pain. >From the guy who has recovered more then a few ancient GPS systems. :-) I suspect if there is a better answer you will get it here. Good luck. Regards Paul WB8TSL On Wed, Nov 4, 2015 at 2:25 PM, Stephen Farthing wrote: > Hi all, > > I have the chance to buy a new boxed unit. Having glanced at the manual I > understand that the configuration software runs under Windows 95 and uses a > serial RS232 port. The only Windows box I have now runs Windows 10 and has > USB only. So my questions are, can I run the config software under Windows > 10 and will a USB to serial adaptor work with it? I will need to make a > power supply for it as I think it requires 24 volts. That should be no > problem. > > Any comments great fully received. > > Thanks in advance, > > Steve G0XAR > ___ > 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Hi In general running Win 95 software on Win 10 is not a real good bet. It’s slightly more likely to work with Win 10 Pro than with the entry level version. Bob > On Nov 4, 2015, at 2:25 PM, Stephen Farthing wrote: > > Hi all, > > I have the chance to buy a new boxed unit. Having glanced at the manual I > understand that the configuration software runs under Windows 95 and uses a > serial RS232 port. The only Windows box I have now runs Windows 10 and has > USB only. So my questions are, can I run the config software under Windows > 10 and will a USB to serial adaptor work with it? I will need to make a > power supply for it as I think it requires 24 volts. That should be no > problem. > > Any comments great fully received. > > Thanks in advance, > > Steve G0XAR > ___ > 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Hi Steve, I've got one of these, also came to me new in the box but that was around twelve years ago and other than a short period of testing has stayed there ever since, nothing wrong with it as far as I can remember just too much stuff, too much to do, and Thunderbolts and the like do take up a bit less space:-) How long do you have before you need to make a decision?, I can let you have a copy of the software if you want to play with that first, and the manual too if you don't have ongoing access to it at the moment. Interestingly, the Proteus software is badged Symmetricom, although I don't recall anything to suggest that they and Parthus had any working relationship. My manual indicates the software as suitable for Win95, Win98, and NT, which does rather show its age:-), but I've run it ok on a P4 WinXP machine using a standard RS232 port. I could try an installation under Win7 via a USB to serial adapter but my Proteus is tucked away in its box so I would need a bit of time to get it set up, and whilst that obviously won't confirm it will work with Win 10 it might at least be a step nearer. Unfortunately whilst the manual does give information on the message format for the time port output it doesn't for the control port, just refers to the supplied CDU software. Presumably it could be sniffed at the port but the manual does state that the messages are binary format and that a terminal emulator can't be used for control. The Proteus was supplied in 12, 24, and 48 Volt versions, and this will be indicated on the label on the unit. One thing to be aware of, just in case it doesn't come with original antenna, is that the antenna port feeds 12 Volts DC to the antenna, rather than 5 Volts, or even 3.3 Volts, as often found later. As far as I remember this isn't made clear in the manual. Week 1024 rollover is discussed in the manual and shouldn't have been an issue, at least that's what they said for the 1999 rollover:-), but again I can check that if you don't need to make a decision in the next day or so. Regards Nigel GM8PZR Hi all, I have the chance to buy a new boxed unit. Having glanced at the manual I understand that the configuration software runs under Windows 95 and uses a serial RS232 port. The only Windows box I have now runs Windows 10 and has USB only. So my questions are, can I run the config software under Windows 10 and will a USB to serial adaptor work with it? I will need to make a power supply for it as I think it requires 24 volts. That should be no problem. Any comments great fully received. Thanks in advance, Steve G0XAR ___ 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
For multiple reasons I install serial cards in my Win7 desktops. On the issue of the Win95 program, it may not run because the CPU is too fast. Rob NC0b Sent from my iPad > On Nov 4, 2015, at 7:02 PM, "paul swed" wrote: > > > > Steve > My very small 10 cents. > I am pretty sure win 95 had no idea what USB is. I think thats was win98 > sp2 region. > Certainly win10 wouldn't understand what that program was. > > But that said there are dos emulators/virtual machines that might let you > get away with it. The other comment is if the device is circa 95 then most > likely you will also have GPS week rollover issues. > If the thing is selling for $1 then what the heck. Fun is fun. > Otherwise you may want to consider something a bit newer saving the > headaches and complexity. They seem to start in the $125 range and go up. > There are certainly modern solutions at low cost without the pain. >> From the guy who has recovered more then a few ancient GPS systems. :-) > I suspect if there is a better answer you will get it here. Good luck. > Regards > Paul > WB8TSL > >> On Wed, Nov 4, 2015 at 2:25 PM, Stephen Farthing wrote: >> >> Hi all, >> >> I have the chance to buy a new boxed unit. Having glanced at the manual I >> understand that the configuration software runs under Windows 95 and uses a >> serial RS232 port. The only Windows box I have now runs Windows 10 and has >> USB only. So my questions are, can I run the config software under Windows >> 10 and will a USB to serial adaptor work with it? I will need to make a >> power supply for it as I think it requires 24 volts. That should be no >> problem. >> >> Any comments great fully received. >> >> Thanks in advance, >> >> Steve G0XAR >> ___ >> 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. > > > > -- > If this email is spam, report it to > https://support.onlymyemail.com/view/report_spam/ODExMjI6MTgyMjYyODM2OTpyb2JAbmMwYi5jb206ZGVsaXZlcmVk > ___ 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
An update on this just in case anyone else interested... I've confirmed that the Symmetricom CDU software for the Proteus GPS unit will run fine under Windows 7 on a 2009 HP dual-core laptop using a Prolific USB to RS232 convertor. There is no option to select baud rates etc in the CDU software, just the option to select the appropriate COM port between 1 and 4. The Proteus here did not start up displaying the current date, probably not helped by this one not being used for several years, but once the correct date was set via the software it updated correctly and maintained it for short power disconnections at least. The antenna socket does feed 12 Volts to the antenna, although the originally supplied volute style antenna is not particularly sensitive and would definitely require a good outdoor location. A more sensitive Symmetricom 1280 provided reasonable results for indoor testing. Regards Nigel GM8PZR Hi all, I have the chance to buy a new boxed unit. Having glanced at the manual I understand that the configuration software runs under Windows 95 and uses a serial RS232 port. The only Windows box I have now runs Windows 10 and has USB only. So my questions are, can I run the config software under Windows 10 and will a USB to serial adaptor work with it? I will need to make a power supply for it as I think it requires 24 volts. That should be no problem. Any comments great fully received. Thanks in advance, Steve G0XAR ___ 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Why is this an issue? Sent from my iPad > On Nov 8, 2015, at 1:00 PM, "Brendan Giles" wrote: > > > > I was the project manager who was in charge of the NAVSTAR proteus GPS time > and frequency unit.The two GPS rollover dates 1999/2018 were tested in > product test plan. Also various dates were checked upto 2037 for the PC > output message. > Brendan Giles > ___ > 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. > > > > -- > If this email is spam, report it to > https://support.onlymyemail.com/view/report_spam/ODExMjI6MTgyMzU3ODA4MDpyb2JAbmMwYi5jb206ZGVsaXZlcmVk > ___ 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Because the roll over is a pain. Thats good engineering if they checked that far. What happens if you have a receiver that doesn't handle it correctly is you do not tend to get satellite lock because the dates all wrong. You cheat this "The pain part" by figuring out what the date should have been by subtracting 1024 weeks. Seems easy right. Nope. That works for the old austron. But as I say serious thinking. There are some online tools that help. But it all gets old very fast. Regards Paul WB8TSL On Sun, Nov 8, 2015 at 4:01 PM, Rob Sherwood. wrote: > Why is this an issue? > > Sent from my iPad > > > On Nov 8, 2015, at 1:00 PM, "Brendan Giles" > wrote: > > > > > > > > I was the project manager who was in charge of the NAVSTAR proteus GPS > time and frequency unit.The two GPS rollover dates 1999/2018 were tested in > product test plan. Also various dates were checked upto 2037 for the PC > output message. > > Brendan Giles > > ___ > > 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. > > > > > > > > -- > > If this email is spam, report it to > > > https://support.onlymyemail.com/view/report_spam/ODExMjI6MTgyMzU3ODA4MDpyb2JAbmMwYi5jb206ZGVsaXZlcmVk > > > ___ > 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Paul, On 11/09/2015 01:07 AM, paul swed wrote: Because the roll over is a pain. Thats good engineering if they checked that far. What happens if you have a receiver that doesn't handle it correctly is you do not tend to get satellite lock because the dates all wrong. No. The GPS internal date-format avoids this issue altogether, it's the conversion from the GPS date gears to "user dates" that gets confused due to lack of additional bits for GPS weeks, but the GPS receiver can keep operate even if the GPS weeks wrap, with very little software concern. So, after the GPS week wrapping, wherever it occurs for a receiver, only means that the published user date becomes wrong, not the GPS system internal date, the receiver keeps working through it, whatever it is. You cheat this "The pain part" by figuring out what the date should have been by subtracting 1024 weeks. Seems easy right. Nope. I've only seen receivers fail in their date conversion, and in exactly 1024 weeks. Cheers, Magnus That works for the old austron. But as I say serious thinking. There are some online tools that help. But it all gets old very fast. Regards Paul WB8TSL On Sun, Nov 8, 2015 at 4:01 PM, Rob Sherwood. wrote: Why is this an issue? Sent from my iPad On Nov 8, 2015, at 1:00 PM, "Brendan Giles" wrote: I was the project manager who was in charge of the NAVSTAR proteus GPS time and frequency unit.The two GPS rollover dates 1999/2018 were tested in product test plan. Also various dates were checked upto 2037 for the PC output message. Brendan Giles ___ 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. -- If this email is spam, report it to https://support.onlymyemail.com/view/report_spam/ODExMjI6MTgyMzU3ODA4MDpyb2JAbmMwYi5jb206ZGVsaXZlcmVk ___ 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. ___ 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Thanks. What I intended to ask is why the problem exists, not implying that it doesn't matter. Rob, NC0B Sent from my iPad > On Nov 8, 2015, at 6:30 PM, "paul swed" wrote: > > > > Because the roll over is a pain. > Thats good engineering if they checked that far. > What happens if you have a receiver that doesn't handle it correctly is you > do not tend to get satellite lock because the dates all wrong. > You cheat this "The pain part" by figuring out what the date should have > been by subtracting 1024 weeks. Seems easy right. Nope. > That works for the old austron. But as I say serious thinking. There are > some online tools that help. But it all gets old very fast. > Regards > Paul > WB8TSL > >> On Sun, Nov 8, 2015 at 4:01 PM, Rob Sherwood. wrote: >> >> Why is this an issue? >> >> Sent from my iPad >> On Nov 8, 2015, at 1:00 PM, "Brendan Giles" >>> wrote: >>> >>> >>> >>> I was the project manager who was in charge of the NAVSTAR proteus GPS >> time and frequency unit.The two GPS rollover dates 1999/2018 were tested in >> product test plan. Also various dates were checked upto 2037 for the PC >> output message. >>> Brendan Giles >>> ___ >>> 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. >>> >>> >>> >>> -- >>> If this email is spam, report it to >> https://support.onlymyemail.com/view/report_spam/ODExMjI6MTgyMzU3ODA4MDpyb2JAbmMwYi5jb206ZGVsaXZlcmVk >> ___ >> 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. > > > > -- > If this email is spam, report it to > https://support.onlymyemail.com/view/report_spam/ODExMjI6MTgyMzYxMTQxOTpyb2JAbmMwYi5jb206ZGVsaXZlcmVk > ___ 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Hmmm then why do I have to figure it out at all? I don't care what the date says. Only that the Austron locks and does its frequency offset compare. It would be great not to have to do this. Regards Paul WB8TSL On Sun, Nov 8, 2015 at 9:06 PM, Magnus Danielson wrote: > Paul, > > On 11/09/2015 01:07 AM, paul swed wrote: > >> Because the roll over is a pain. >> Thats good engineering if they checked that far. >> What happens if you have a receiver that doesn't handle it correctly is >> you >> do not tend to get satellite lock because the dates all wrong. >> > > No. The GPS internal date-format avoids this issue altogether, it's the > conversion from the GPS date gears to "user dates" that gets confused due > to lack of additional bits for GPS weeks, but the GPS receiver can keep > operate even if the GPS weeks wrap, with very little software concern. So, > after the GPS week wrapping, wherever it occurs for a receiver, only means > that the published user date becomes wrong, not the GPS system internal > date, the receiver keeps working through it, whatever it is. > > You cheat this "The pain part" by figuring out what the date should have >> been by subtracting 1024 weeks. Seems easy right. Nope. >> > > I've only seen receivers fail in their date conversion, and in exactly > 1024 weeks. > > Cheers, > Magnus > > > That works for the old austron. But as I say serious thinking. There are >> some online tools that help. But it all gets old very fast. >> Regards >> Paul >> WB8TSL >> >> On Sun, Nov 8, 2015 at 4:01 PM, Rob Sherwood. wrote: >> >> Why is this an issue? >>> >>> Sent from my iPad >>> >>> On Nov 8, 2015, at 1:00 PM, "Brendan Giles" >>> wrote: >>> I was the project manager who was in charge of the NAVSTAR proteus GPS >>> time and frequency unit.The two GPS rollover dates 1999/2018 were tested >>> in >>> product test plan. Also various dates were checked upto 2037 for the PC >>> output message. >>> Brendan Giles ___ 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. -- If this email is spam, report it to >>> https://support.onlymyemail.com/view/report_spam/ODExMjI6MTgyMzU3ODA4MDpyb2JAbmMwYi5jb206ZGVsaXZlcmVk >>> ___ >>> 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. >> >> ___ > 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
paulsw...@gmail.com said: > Hmmm then why do I have to figure it out at all? I don't care what the date > says. > Only that the Austron locks and does its frequency offset compare. It would > be great not to have to do this. If you don't care about the date, then don't worry about it. It will do everything it did before. The only glitch is that the date will be off by 1024 weeks. If you can't get the right date into your GPS unit, you can work around the issue in software. Just add 1024 weeks to the date until the date is past the build time of your fixup software. That assumes you have some software to work with. That won't help if you are using a program that the vendor no longer supports. -- These are my opinions. 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
OK great conversation. Not sure when but far sooner then later will fire the system up and just let it run for a week. Regards Paul WB8TSL On Mon, Nov 9, 2015 at 1:09 PM, Hal Murray wrote: > > paulsw...@gmail.com said: > > Hmmm then why do I have to figure it out at all? I don't care what the > date > > says. > > > Only that the Austron locks and does its frequency offset compare. It > would > > be great not to have to do this. > > If you don't care about the date, then don't worry about it. > > It will do everything it did before. The only glitch is that the date will > be off by 1024 weeks. > > > If you can't get the right date into your GPS unit, you can work around the > issue in software. Just add 1024 weeks to the date until the date is past > the build time of your fixup software. > > That assumes you have some software to work with. That won't help if you > are > using a program that the vendor no longer supports. > > > -- > These are my opinions. 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Seems to me that there is more to this than just getting the displayed date wrong. It is true that the date will present wrongly, but what about leap seconds? If the GPS week rolls over at 1024, how will the GPS figure out which is the proper calendar date to apply the leap second? -Chuck Harris Hal Murray wrote: paulsw...@gmail.com said: Hmmm then why do I have to figure it out at all? I don't care what the date says. Only that the Austron locks and does its frequency offset compare. It would be great not to have to do this. If you don't care about the date, then don't worry about it. It will do everything it did before. The only glitch is that the date will be off by 1024 weeks. If you can't get the right date into your GPS unit, you can work around the issue in software. Just add 1024 weeks to the date until the date is past the build time of your fixup software. That assumes you have some software to work with. That won't help if you are using a program that the vendor no longer supports. ___ 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Chuck, Because all the leap-second info is kept in GPS-calender form, and essentially indicating current leap-second difference and which GPS week (modulo 256). Check out the ICD for yourself, IS-GPS-200H: 8<--- 20.3.3.5.2.4 Coordinated Universal Time (UTC). Page 18 of subframe 4 includes: (1) the parameters needed to relate GPS time to UTC, and (2) notice to the user regarding the scheduled future or recent past (relative to NAV message upload) value of the delta time due to leap seconds (ΔtLSF), together with the week number (WNLSF) and the day number (DN) at the end of which the leap second becomes effective. "Day one" is the first day relative to the end/start of week and the WNLSF value consists of eight bits which shall be a modulo 256 binary representation of the GPS week number (see paragraph 6.2.4) to which the DN is referenced. The user must account for the truncated nature of this parameter as well as truncation of WN, WNt, and WNLSF due to rollover of full week number (see paragraph 3.3.4(b)). The CS shall manage these parameters such that, when ΔtLS and ΔtLSF differ, the absolute value of the difference between the untruncated WN and WNLSF values shall not exceed 127. Depending upon the relationship of the effectivity date to the user's current GPS time, the following three different UTC/GPS-time relationships exist: a. Whenever the effectivity time indicated by the WNLSF and the DN values is not in the past (relative to the user's present time), and the user's present time does not fall in the time span which starts at six hours prior to the effectivity time and ends at six hours after the effectivity time, the UTC/GPS-time relationship is given by tUTC = (tE - ΔtUTC) [modulo 86400 seconds] where tUTC is in seconds and ΔtUTC = ΔtLS + A0 + A1 (tE - tot + 604800 (WN - WNt)), seconds; tE =GPS time as estimated by the user after correcting tSV for factors described in paragraph 20.3.3.3.3 as well as for selective availability (SA) (dither) effects; ΔtLS = delta time due to leap seconds; A0 and A1 = constant and first order terms of polynomial; tot = reference time for UTC data (reference 20.3.4.5); WN = current week number (derived from subframe 1); WNt = UTC reference week number. The estimated GPS time (tE) shall be in seconds relative to end/start of week. During the normal and short-term extended operations, the reference time for UTC data, tot, is some multiple of 212 seconds occurring approximately 70 hours after the first valid transmission time for this UTC data set (reference 20.3.4.5). The reference time for UTC data (tot) shall be referenced to the start of that week whose number (WNt) is given in word eight of page 18 in subframe 4. The WNt value consists of eight bits which shall be a modulo 256 binary representation of the GPS week number (see paragraph 6.2.4) to which the tot is referenced. The user must account for the truncated nature of this parameter as well as truncation of WN, WNt, and WNLSF due to rollover of full week number (see paragraph 3.3.4(b)). The CS shall manage these parameters such that the absolute value of the difference between the untruncated WN and WNt values shall not exceed 127. b. Whenever the user's current time falls within the time span of six hours prior to the effectivity time to six hours after the effectivity time, proper accommodation of the leap second event with a possible week number transition is provided by the following expression for UTC: tUTC = W[modulo (86400 + ΔtLSF - ΔtLS)], seconds; where W = (tE - ΔtUTC - 43200) [modulo 86400] + 43200, seconds; and the definition of ΔtUTC (as given in 20.3.3.5.2.4a above) applies throughout the transition period. Note that when a leap second is added, unconventional time values of the form 23:59:60.xxx are encountered. Some user equipment may be designed to approximate UTC by decrementing the running count of time within several seconds after the event, thereby promptly returning to a proper time indication. Whenever a leap second event is encountered, the user equipment must consistently implement carries or borrows into any year/week/day counts. c. Whenever the effectivity time of the leap second event, as indicated by the WNLSF and DN values, is in the "past" (relative to the user's current time), and the user’s current time does not fall in the time span as given above in 20.3.3.5.2.4b, the relationship previously given for tUTC in 20.3.3.5.2.4a above is valid except that the value of ΔtLSF is substituted for ΔtLS. The CS will coordinate the update of UTC parameters at a future upload so as to maintain a proper continuity of the tUTC time scale. --->8 The GPS date gears is different to normal dates, and all relevant events is related in the form of these gears (or own set of scales if you so like). The UTC information is no exception, it is more of the same, so getting these things right follows the same pattern. You can do all
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
GPS Time ignores (does not deal with) "Leap Seconds." It is dealt with in the software translation from GPS time to UTC or local time. That is part of the reason there is a 16 second time difference between GPS Time and UTC/local time. --- Graham == On Mon, Nov 9, 2015 at 4:15 PM, Chuck Harris wrote: > Seems to me that there is more to this than just > getting the displayed date wrong. > > It is true that the date will present wrongly, but > what about leap seconds? > > If the GPS week rolls over at 1024, how will the > GPS figure out which is the proper calendar date > to apply the leap second? > > -Chuck Harris > > Hal Murray wrote: > >> >> paulsw...@gmail.com said: >> >>> Hmmm then why do I have to figure it out at all? I don't care what the >>> date >>> says. >>> >> >> Only that the Austron locks and does its frequency offset compare. It >>> would >>> be great not to have to do this. >>> >> >> If you don't care about the date, then don't worry about it. >> >> It will do everything it did before. The only glitch is that the date >> will >> be off by 1024 weeks. >> >> >> If you can't get the right date into your GPS unit, you can work around >> the >> issue in software. Just add 1024 weeks to the date until the date is past >> the build time of your fixup software. >> >> That assumes you have some software to work with. That won't help if you >> are >> using a program that the vendor no longer supports. >> >> >> ___ > 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Well for the heck of it I just fired the austron 2201 up. Date was circa 1980 or something way back. Guess the battery went. That said set the date and time to UTC and let it go. Almanac seems to grab a satellite every now and then but it does not go into the full track mode. I normally cheat this with a semi-automatic acquire and give it a list of know satellites. But will just let it run for a day or so. Regards Paul WB8TSL Need to watch it this is not my thread. On Mon, Nov 9, 2015 at 8:11 PM, Graham / KE9H wrote: > GPS Time ignores (does not deal with) "Leap Seconds." > It is dealt with in the software translation from GPS time to UTC or local > time. > That is part of the reason there is a 16 second time difference between GPS > Time and UTC/local time. > > --- Graham > > == > > On Mon, Nov 9, 2015 at 4:15 PM, Chuck Harris wrote: > > > Seems to me that there is more to this than just > > getting the displayed date wrong. > > > > It is true that the date will present wrongly, but > > what about leap seconds? > > > > If the GPS week rolls over at 1024, how will the > > GPS figure out which is the proper calendar date > > to apply the leap second? > > > > -Chuck Harris > > > > Hal Murray wrote: > > > >> > >> paulsw...@gmail.com said: > >> > >>> Hmmm then why do I have to figure it out at all? I don't care what the > >>> date > >>> says. > >>> > >> > >> Only that the Austron locks and does its frequency offset compare. It > >>> would > >>> be great not to have to do this. > >>> > >> > >> If you don't care about the date, then don't worry about it. > >> > >> It will do everything it did before. The only glitch is that the date > >> will > >> be off by 1024 weeks. > >> > >> > >> If you can't get the right date into your GPS unit, you can work around > >> the > >> issue in software. Just add 1024 weeks to the date until the date is > past > >> the build time of your fixup software. > >> > >> That assumes you have some software to work with. That won't help if > you > >> are > >> using a program that the vendor no longer supports. > >> > >> > >> ___ > > 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. > ___ 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.
Re: [time-nuts] NAVSTAR proteus GPS time and frequency unit
Magnus, Thanks for the detailed reply. I haven't had a need (read: no customer has paid me to do so...) to wallow through the GPS ICD, so that document is foreign to me. Your explanation clarifies the situation... Now it makes sense. Thanks! -Chuck Harris Magnus Danielson wrote: Chuck, Because all the leap-second info is kept in GPS-calender form, and essentially indicating current leap-second difference and which GPS week (modulo 256). Check out the ICD for yourself, IS-GPS-200H: 8<--- 20.3.3.5.2.4 Coordinated Universal Time (UTC). Page 18 of subframe 4 includes: (1) the parameters needed to relate GPS time to UTC, and (2) notice to the user regarding the scheduled future or recent past (relative to NAV message upload) value of the delta time due to leap seconds (ΔtLSF), together with the week number (WNLSF) and the day number (DN) at the end of which the leap second becomes effective. "Day one" is the first day relative to the end/start of week and the WNLSF value consists of eight bits which shall be a modulo 256 binary representation of the GPS week number (see paragraph 6.2.4) to which the DN is referenced. The user must account for the truncated nature of this parameter as well as truncation of WN, WNt, and WNLSF due to rollover of full week number (see paragraph 3.3.4(b)). The CS shall manage these parameters such that, when ΔtLS and ΔtLSF differ, the absolute value of the difference between the untruncated WN and WNLSF values shall not exceed 127. Depending upon the relationship of the effectivity date to the user's current GPS ... ___ 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.