Hi sorry for a possibly OT post. Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle. Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. Hold over if there are gaps in GPS coverage is also a major plus. We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. Yes I am aware I could feed a 1 pps signal into a laptop and use that as a time server and I may end up going that route. There is a small Ethernet LAN in the vehicle. The pc's currently get their time via a wireless connection to various NTP servers. I need to be able to ensure accurate time on the PC's if there is no wireless coverage. This is for a one off project so piecing together various parts is an option but a single box COTS solution would be nice. I've found a few candidates via web searches but would welcome any feed back. Thanks in advance Mark Spencer

What's your budget? I've done this with 1U sized NTP servers from Symmetricom (S300 and S350 systems) for mobile military use. These are a few thousand bucks a pop. They're rugged, and held up just fine in places the military goes.Compared to the rest of the system I was working on, this was quite small in comparison and we used more than one at each location. My personal one died recently so I'm working on developing a cape for the BeagleBone Black. The prototype is working just fine so far so I'm moving forward with a board layout and eventual sale to the list members if there is any interest (I'm not asking for interest yet). -Bob On Tue, May 12, 2015 at 11:11 AM, Mark Spencer <mark@alignedsolutions.com> wrote: > Hi sorry for a possibly OT post. > Has anyone had practical experience with small commercially available time > servers / ntp servers suitable for mobile use in a vehicle. > > The use case is I am in need of an accurate (ie. within 100 ms) time > source for several pc's in moving vehicle. Being able to run directly > off a 13.8 or 28 VDC source would be a major plus but AC power is also > available. > > Hold over if there are gaps in GPS coverage is also a major plus. > > We already have a GPS with a 1 pps output, but an integrated box with it's > own GPS would be best. > > Yes I am aware I could feed a 1 pps signal into a laptop and use that as a > time server and I may end up going that route. > > There is a small Ethernet LAN in the vehicle. The pc's currently get > their time via a wireless connection to various NTP servers. I need to be > able to ensure accurate time on the PC's if there is no wireless coverage. > > > This is for a one off project so piecing together various parts is an > option but a single box COTS solution would be nice. I've found a few > candidates via web searches but would welcome any feed back. > > Thanks in advance > > Mark Spencer > _______________________________________________ > 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. >

Hi! You can try Laureline GPS NTP Server <https://www.tindie.com/products/gxti/laureline-gps-ntp-server/>. I have no personal experience with this box but it seems to satisfy all your requirements. Edésio On Tue, May 12, 2015 at 10:11:52AM -0700, Mark Spencer wrote: > Hi sorry for a possibly OT post. > Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. > > The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle. Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. > > Hold over if there are gaps in GPS coverage is also a major plus. > > We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. > > Yes I am aware I could feed a 1 pps signal into a laptop and use that as a time server and I may end up going that route. > > There is a small Ethernet LAN in the vehicle. The pc's currently get their time via a wireless connection to various NTP servers. I need to be able to ensure accurate time on the PC's if there is no wireless coverage. > > > This is for a one off project so piecing together various parts is an option but a single box COTS solution would be nice. I've found a few candidates via web searches but would welcome any feed back. > > Thanks in advance > > Mark Spencer > _______________________________________________ > 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.

On Tue, May 12, 2015 at 7:11 PM, Mark Spencer <mark@alignedsolutions.com> wrote: > Hi sorry for a possibly OT post. > Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. I don't know about any commercially-available products, but it sounds like it'd be pretty straightforward to do with a Raspberry Pi or something similar if you don't mind a little bit of DIY. What constraints do you have on budget, size, power requirements, and cooling? > The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle. Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. The Pi runs on 5V DC. DC-DC buck converters that can convert 7-35V to 5V DC are cheap, efficient, and widely available. Shouldn't be a problem. > Hold over if there are gaps in GPS coverage is also a major plus. How long would you need holdover? Seconds or minutes (e.g. driving through a tunnel)? Hours? Days? Would the computers in the vehicle be subject to large temperature shifts? A Pi should be able to handle +/- 100ms of holdover in the minutes-to-hours range using NTP. > We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. A tiny integrated module like the Adafruit Ultimate GPS breakout[1] is cheap, handy, and emits a 1PPS signal. It's also extremely small and can be purchased in "hat" form[2] that mounts directly to the Pi. Cheers! -Pete [1] https://www.adafruit.com/products/746 [2] https://www.adafruit.com/products/2324 -- Pete Stephenson On Tue, May 12, 2015 at 7:11 PM, Mark Spencer <mark@alignedsolutions.com> wrote: > Hi sorry for a possibly OT post. > Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. > > The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle. Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. > > Hold over if there are gaps in GPS coverage is also a major plus. > > We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. > > Yes I am aware I could feed a 1 pps signal into a laptop and use that as a time server and I may end up going that route. > > There is a small Ethernet LAN in the vehicle. The pc's currently get their time via a wireless connection to various NTP servers. I need to be able to ensure accurate time on the PC's if there is no wireless coverage. > > > This is for a one off project so piecing together various parts is an option but a single box COTS solution would be nice. I've found a few candidates via web searches but would welcome any feed back. > > Thanks in advance > > Mark Spencer > _______________________________________________ > 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. -- Pete Stephenson

Thanks for this. This (and the other responses) were the type of answers I was hoping for. The budget is probably up to several thousand for a robust COTS product that won't add significant operational hassles. (Kludging a laptop to run as an NTP server would be an example of a solution that would add operational hassles.) Equipment designed for rack mounting is a bit less than ideal (the equipment bay in the vehicle is not really set up for rack mounted gear) but we could probably work out a way to mount a one u device, and mounting a laptop adds it's own set of challenges, although a laptop can be mounted outside of the equipment bay. The ideal form factor would be something the size of a small paper back book (or smaller) that could be surface mounted or secured via clamps to a piece of tubing that is already in the equipment bay. Sent from my iPad On 2015-05-12, at 3:03 PM, Bob Darlington <rdarlington@gmail.com> wrote: > What's your budget? I've done this with 1U sized NTP servers from > Symmetricom (S300 and S350 systems) for mobile military use. These are a > few thousand bucks a pop. They're rugged, and held up just fine in places > the military goes.Compared to the rest of the system I was working on, this > was quite small in comparison and we used more than one at each location. > My personal one died recently so I'm working on developing a cape for the > BeagleBone Black. The prototype is working just fine so far so I'm moving > forward with a board layout and eventual sale to the list members if there > is any interest (I'm not asking for interest yet). > > -Bob > > On Tue, May 12, 2015 at 11:11 AM, Mark Spencer <mark@alignedsolutions.com> > wrote: > >> Hi sorry for a possibly OT post. >> Has anyone had practical experience with small commercially available time >> servers / ntp servers suitable for mobile use in a vehicle. >> >> The use case is I am in need of an accurate (ie. within 100 ms) time >> source for several pc's in moving vehicle. Being able to run directly >> off a 13.8 or 28 VDC source would be a major plus but AC power is also >> available. >> >> Hold over if there are gaps in GPS coverage is also a major plus. >> >> We already have a GPS with a 1 pps output, but an integrated box with it's >> own GPS would be best. >> >> Yes I am aware I could feed a 1 pps signal into a laptop and use that as a >> time server and I may end up going that route. >> >> There is a small Ethernet LAN in the vehicle. The pc's currently get >> their time via a wireless connection to various NTP servers. I need to be >> able to ensure accurate time on the PC's if there is no wireless coverage. >> >> >> This is for a one off project so piecing together various parts is an >> option but a single box COTS solution would be nice. I've found a few >> candidates via web searches but would welcome any feed back. >> >> Thanks in advance >> >> Mark Spencer >> _______________________________________________ >> 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. >

The quickest no-cost way to get decent hold over if all you need is about 100 ms is to configure all you NTP users to be part of an "orphan" network. When the outside NTP server is lost the island will look at the set of local NTP systems that agree with each other. So you in effect use the most stable internal clocks for hold over. It is just a matter if setting up all the ntp.conf files on all the computers to do this. On Tue, May 12, 2015 at 3:03 PM, Bob Darlington <rdarlington@gmail.com> wrote: > What's your budget? I've done this with 1U sized NTP servers from > Symmetricom (S300 and S350 systems) for mobile military use. These are a > few thousand bucks a pop. They're rugged, and held up just fine in places > the military goes.Compared to the rest of the system I was working on, this > was quite small in comparison and we used more than one at each location. > My personal one died recently so I'm working on developing a cape for the > BeagleBone Black. The prototype is working just fine so far so I'm moving > forward with a board layout and eventual sale to the list members if there > is any interest (I'm not asking for interest yet). > > -Bob > > On Tue, May 12, 2015 at 11:11 AM, Mark Spencer <mark@alignedsolutions.com> > wrote: > >> Hi sorry for a possibly OT post. >> Has anyone had practical experience with small commercially available time >> servers / ntp servers suitable for mobile use in a vehicle. >> >> The use case is I am in need of an accurate (ie. within 100 ms) time >> source for several pc's in moving vehicle. Being able to run directly >> off a 13.8 or 28 VDC source would be a major plus but AC power is also >> available. >> >> Hold over if there are gaps in GPS coverage is also a major plus. >> >> We already have a GPS with a 1 pps output, but an integrated box with it's >> own GPS would be best. >> >> Yes I am aware I could feed a 1 pps signal into a laptop and use that as a >> time server and I may end up going that route. >> >> There is a small Ethernet LAN in the vehicle. The pc's currently get >> their time via a wireless connection to various NTP servers. I need to be >> able to ensure accurate time on the PC's if there is no wireless coverage. >> >> >> This is for a one off project so piecing together various parts is an >> option but a single box COTS solution would be nice. I've found a few >> candidates via web searches but would welcome any feed back. >> >> Thanks in advance >> >> Mark Spencer >> _______________________________________________ >> 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. -- Chris Albertson Redondo Beach, California

Thanks. Yep running an extra Dc to Dc converter is an option but we already have access to clean 28 and 13.8 VDC supplies with some extra capacity. We could likely provide up to a 100 watts of power for this system (I doubt it would need that much.) The hold over requirement is in the range of several hours. The temperature swings could be fairly large (ie. cold soak outside at minus 35C, then inside a heated garage, plus what ever temperature the equipment bay rises to when the vehicle has been operating for some time probably less than 85 deg C.) mounting the equipment in locations other than the equipment bay would likely result in lower max temperatures. I'm not sure about the cooling capacity of the equipment bay, but there are other areas with climate control systems where this device could be installed if needed. I'm fairly comfortable that a device that generated up to 100 watts of heat could be accommodated (ie, I would assume all of the electrical power going into the device gets turned into heat) but would need to double check this. The size is somewhat flexible. To a certain extent the requirements could be adjusted to fit an existing COTS product that was perceived as generally suited to the application. As this is a one off requirement, that will be in use for a limited time some limitations can be worked around or lived with. The budget could be several thousand dollars. I thought about a Raspberry Pi type of solution, but need to factor in the cost of my time or that of someone else, plus there is a strong desire to either drop in a COTS "black box" or use a laptop. Thanks for the comments. Sent from my iPad On 2015-05-12, at 3:54 PM, Pete Stephenson <pete@heypete.com> wrote: > On Tue, May 12, 2015 at 7:11 PM, Mark Spencer <mark@alignedsolutions.com> wrote: >> Hi sorry for a possibly OT post. >> Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. > > I don't know about any commercially-available products, but it sounds > like it'd be pretty straightforward to do with a Raspberry Pi or > something similar if you don't mind a little bit of DIY. > > What constraints do you have on budget, size, power requirements, and cooling? > >> The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle. Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. > > The Pi runs on 5V DC. DC-DC buck converters that can convert 7-35V to > 5V DC are cheap, efficient, and widely available. Shouldn't be a > problem. > >> Hold over if there are gaps in GPS coverage is also a major plus. > > How long would you need holdover? Seconds or minutes (e.g. driving > through a tunnel)? Hours? Days? Would the computers in the vehicle be > subject to large temperature shifts? > > A Pi should be able to handle +/- 100ms of holdover in the > minutes-to-hours range using NTP. > >> We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. > > A tiny integrated module like the Adafruit Ultimate GPS breakout[1] is > cheap, handy, and emits a 1PPS signal. It's also extremely small and > can be purchased in "hat" form[2] that mounts directly to the Pi. > > Cheers! > -Pete > > [1] https://www.adafruit.com/products/746 > [2] https://www.adafruit.com/products/2324 > > -- > Pete Stephenson > > On Tue, May 12, 2015 at 7:11 PM, Mark Spencer <mark@alignedsolutions.com> wrote: >> Hi sorry for a possibly OT post. >> Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. >> >> The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle. Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. >> >> Hold over if there are gaps in GPS coverage is also a major plus. >> >> We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. >> >> Yes I am aware I could feed a 1 pps signal into a laptop and use that as a time server and I may end up going that route. >> >> There is a small Ethernet LAN in the vehicle. The pc's currently get their time via a wireless connection to various NTP servers. I need to be able to ensure accurate time on the PC's if there is no wireless coverage. >> >> >> This is for a one off project so piecing together various parts is an option but a single box COTS solution would be nice. I've found a few candidates via web searches but would welcome any feed back. >> >> Thanks in advance >> >> Mark Spencer >> _______________________________________________ >> 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. > > > > -- > Pete Stephenson > _______________________________________________ > 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 you already have several computers running NTP why add yet anther? Configure them all as peers and add an reference clock. Do you really need a dedicated NTP server? I'd think that all you need is a reference clock of some kind, such as a GPS receiver and to change some nt..conf files. On Tue, May 12, 2015 at 6:26 PM, Mark Spencer <mark@alignedsolutions.com> wrote: > Thanks for this. This (and the other responses) were the type of answers I was hoping for. > > The budget is probably up to several thousand for a robust COTS product that won't add significant operational hassles. (Kludging a laptop to run as an NTP server would be an example of a solution that would add operational hassles.) Equipment designed for rack mounting is a bit less than ideal (the equipment bay in the vehicle is not really set up for rack mounted gear) but we could probably work out a way to mount a one u device, and mounting a laptop adds it's own set of challenges, although a laptop can be mounted outside of the equipment bay. The ideal form factor would be something the size of a small paper back book (or smaller) that could be surface mounted or secured via clamps to a piece of tubing that is already in the equipment bay. > > > > Sent from my iPad > > On 2015-05-12, at 3:03 PM, Bob Darlington <rdarlington@gmail.com> wrote: > >> What's your budget? I've done this with 1U sized NTP servers from >> Symmetricom (S300 and S350 systems) for mobile military use. These are a >> few thousand bucks a pop. They're rugged, and held up just fine in places >> the military goes.Compared to the rest of the system I was working on, this >> was quite small in comparison and we used more than one at each location. >> My personal one died recently so I'm working on developing a cape for the >> BeagleBone Black. The prototype is working just fine so far so I'm moving >> forward with a board layout and eventual sale to the list members if there >> is any interest (I'm not asking for interest yet). >> >> -Bob >> >> On Tue, May 12, 2015 at 11:11 AM, Mark Spencer <mark@alignedsolutions.com> >> wrote: >> >>> Hi sorry for a possibly OT post. >>> Has anyone had practical experience with small commercially available time >>> servers / ntp servers suitable for mobile use in a vehicle. >>> >>> The use case is I am in need of an accurate (ie. within 100 ms) time >>> source for several pc's in moving vehicle. Being able to run directly >>> off a 13.8 or 28 VDC source would be a major plus but AC power is also >>> available. >>> >>> Hold over if there are gaps in GPS coverage is also a major plus. >>> >>> We already have a GPS with a 1 pps output, but an integrated box with it's >>> own GPS would be best. >>> >>> Yes I am aware I could feed a 1 pps signal into a laptop and use that as a >>> time server and I may end up going that route. >>> >>> There is a small Ethernet LAN in the vehicle. The pc's currently get >>> their time via a wireless connection to various NTP servers. I need to be >>> able to ensure accurate time on the PC's if there is no wireless coverage. >>> >>> >>> This is for a one off project so piecing together various parts is an >>> option but a single box COTS solution would be nice. I've found a few >>> candidates via web searches but would welcome any feed back. >>> >>> Thanks in advance >>> >>> Mark Spencer >>> _______________________________________________ >>> 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. -- Chris Albertson Redondo Beach, California

All interesting solutions. For the advocates of RPi solutions, I put about half a dozen in to support some non mission critical infrastructure about a year ago. We are using them for for logging, reading QR codes, running a vending machine, kiosk web browsers, and similar tasks. In short, nothing requiring heavily lifting. I've been incredibly dissappointed in the results. Well over half of them have needed replacement and not a one runs reliably. They need rebooting at intervals from hours to a few tens of days to recover from total lock up. The problem is not environmental, power or SD cards. As such, I'd be hard pressed to go with such a solution for Mark's problem. Soekris single board PCs are still out there, have a decent ecosystem, and are pretty rugged. Hard to beat for the budget requested. And decent GPS NTP implementations are documented. Failing that a nice used Symetricomm :) > On May 12, 2015, at 21:09, Mark Spencer <mark@alignedsolutions.com> wrote: > > Thanks. Yep running an extra Dc to Dc converter is an option but we already have access to clean 28 and 13.8 VDC supplies with some extra capacity. We could likely provide up to a 100 watts of power for this system (I doubt it would need that much.) > > The hold over requirement is in the range of several hours. The temperature swings could be fairly large (ie. cold soak outside at minus 35C, then inside a heated garage, plus what ever temperature the equipment bay rises to when the vehicle has been operating for some time probably less than 85 deg C.) mounting the equipment in locations other than the equipment bay would likely result in lower max temperatures. > > I'm not sure about the cooling capacity of the equipment bay, but there are other areas with climate control systems where this device could be installed if needed. I'm fairly comfortable that a device that generated up to 100 watts of heat could be accommodated (ie, I would assume all of the electrical power going into the device gets turned into heat) but would need to double check this. > > The size is somewhat flexible. > > To a certain extent the requirements could be adjusted to fit an existing COTS product that was perceived as generally suited to the application. As this is a one off requirement, that will be in use for a limited time some limitations can be worked around or lived with. > > The budget could be several thousand dollars. > > I thought about a Raspberry Pi type of solution, but need to factor in the cost of my time or that of someone else, plus there is a strong desire to either drop in a COTS "black box" or use a laptop. > > Thanks for the comments. > > > Sent from my iPad > >> On 2015-05-12, at 3:54 PM, Pete Stephenson <pete@heypete.com> wrote: >> >>> On Tue, May 12, 2015 at 7:11 PM, Mark Spencer <mark@alignedsolutions.com> wrote: >>> Hi sorry for a possibly OT post. >>> Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. >> >> I don't know about any commercially-available products, but it sounds >> like it'd be pretty straightforward to do with a Raspberry Pi or >> something similar if you don't mind a little bit of DIY. >> >> What constraints do you have on budget, size, power requirements, and cooling? >> >>> The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle. Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. >> >> The Pi runs on 5V DC. DC-DC buck converters that can convert 7-35V to >> 5V DC are cheap, efficient, and widely available. Shouldn't be a >> problem. >> >>> Hold over if there are gaps in GPS coverage is also a major plus. >> >> How long would you need holdover? Seconds or minutes (e.g. driving >> through a tunnel)? Hours? Days? Would the computers in the vehicle be >> subject to large temperature shifts? >> >> A Pi should be able to handle +/- 100ms of holdover in the >> minutes-to-hours range using NTP. >> >>> We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. >> >> A tiny integrated module like the Adafruit Ultimate GPS breakout[1] is >> cheap, handy, and emits a 1PPS signal. It's also extremely small and >> can be purchased in "hat" form[2] that mounts directly to the Pi. >> >> Cheers! >> -Pete >> >> [1] https://www.adafruit.com/products/746 >> [2] https://www.adafruit.com/products/2324 >> >> -- >> Pete Stephenson >> >>> On Tue, May 12, 2015 at 7:11 PM, Mark Spencer <mark@alignedsolutions.com> wrote: >>> Hi sorry for a possibly OT post. >>> Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. >>> >>> The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle. Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. >>> >>> Hold over if there are gaps in GPS coverage is also a major plus. >>> >>> We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. >>> >>> Yes I am aware I could feed a 1 pps signal into a laptop and use that as a time server and I may end up going that route. >>> >>> There is a small Ethernet LAN in the vehicle. The pc's currently get their time via a wireless connection to various NTP servers. I need to be able to ensure accurate time on the PC's if there is no wireless coverage. >>> >>> >>> This is for a one off project so piecing together various parts is an option but a single box COTS solution would be nice. I've found a few candidates via web searches but would welcome any feed back. >>> >>> Thanks in advance >>> >>> Mark Spencer >>> _______________________________________________ >>> 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. >> >> >> >> -- >> Pete Stephenson >> _______________________________________________ >> 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.

Might look at this: http://qulsar.com/Products/Managed_Timing_Engines/MTE_Board_P6X.html It has PTP, sNTP, comes with a TCXO, OCXO as an option or bring your own oscillator through the 40 pin connector. Link On May 12, 2015, at 10:11 AM, Mark Spencer <mark@alignedsolutions.com> wrote: > Hi sorry for a possibly OT post. > Has anyone had practical experience with small commercially available time servers / ntp servers suitable for mobile use in a vehicle. > > The use case is I am in need of an accurate (ie. within 100 ms) time source for several pc's in moving vehicle. Being able to run directly off a 13.8 or 28 VDC source would be a major plus but AC power is also available. > > Hold over if there are gaps in GPS coverage is also a major plus. > > We already have a GPS with a 1 pps output, but an integrated box with it's own GPS would be best. > > Yes I am aware I could feed a 1 pps signal into a laptop and use that as a time server and I may end up going that route. > > There is a small Ethernet LAN in the vehicle. The pc's currently get their time via a wireless connection to various NTP servers. I need to be able to ensure accurate time on the PC's if there is no wireless coverage. > > > This is for a one off project so piecing together various parts is an option but a single box COTS solution would be nice. I've found a few candidates via web searches but would welcome any feed back. > > Thanks in advance > > Mark Spencer > _______________________________________________ > 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.