Re: [time-nuts] Z3801A Problem
Hi There were a *lot* of firmware updates to the Oncores. I don't know if the re-flash images are still out there or not. If they are, it wouldn't hurt to upgrade the card. I don't think it will fix your problem, but it won't hurt either. Bob On Nov 7, 2012, at 1:06 AM, Ed Palmer ed_pal...@sasktel.net wrote: Hi Mike, My unit has the standard 6 channel VP. In fact, here's the ID message: COPYRIGHT 1991-1995 MOTOROLA INC. SFTW P/N # 98-P39972M SOFTWARE VER # 8 SOFTWARE REV # 4 SOFTWARE DATE 13 JUL 1995 MODEL #B1121P1114 HDWR P/N # _ SERIAL # SSG0239632 MANUFACTUR DATE 7H18 OPTIONS LISTIB I understand that the 'B1' start to the model number means that it's quite old. I don't remember if I ever did a full reset so I just did one. We'll see what happens. Thanks, Ed On 11/6/2012 10:20 PM, Mike S wrote: On 11/6/2012 2:59 PM, Ed Palmer wrote: But if this is a firmware issue, shouldn't there be lots of Z3801As with this problem? I suspect that there's a fault with my unit, but I can't imagine what. Does your unit by chance have an 8 channel Oncore VP instead of the stock 6 channel one? Also, have you tried a full reset (:system:preset)? ___ 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] Z3801A Problem
Never found an Oncore firmware file... can you point me to anyone of them? I'm curious to see one. On Wed, Nov 7, 2012 at 1:30 PM, Bob Camp li...@rtty.us wrote: Hi There were a *lot* of firmware updates to the Oncores. I don't know if the re-flash images are still out there or not. If they are, it wouldn't hurt to upgrade the card. I don't think it will fix your problem, but it won't hurt either. Bob On Nov 7, 2012, at 1:06 AM, Ed Palmer ed_pal...@sasktel.net wrote: Hi Mike, My unit has the standard 6 channel VP. In fact, here's the ID message: COPYRIGHT 1991-1995 MOTOROLA INC. SFTW P/N # 98-P39972M SOFTWARE VER # 8 SOFTWARE REV # 4 SOFTWARE DATE 13 JUL 1995 MODEL #B1121P1114 HDWR P/N # _ SERIAL # SSG0239632 MANUFACTUR DATE 7H18 OPTIONS LISTIB I understand that the 'B1' start to the model number means that it's quite old. I don't remember if I ever did a full reset so I just did one. We'll see what happens. Thanks, Ed On 11/6/2012 10:20 PM, Mike S wrote: On 11/6/2012 2:59 PM, Ed Palmer wrote: But if this is a firmware issue, shouldn't there be lots of Z3801As with this problem? I suspect that there's a fault with my unit, but I can't imagine what. Does your unit by chance have an 8 channel Oncore VP instead of the stock 6 channel one? Also, have you tried a full reset (:system:preset)? ___ 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] Z3801A Problem
Back in the early 2000's Randy Warner was working at Synergy and posting here. He provided a lot of good and accurate details about the Oncores to the list. You might want to search the archive for his name and scan through the posts. He was a fabulous, accurate source while he was posting here, but left Synergy around 2006-2007. One document he provided is this: http://www.febo.com/pages/hardware/VPCommands.pdf In there he mentions the VP firmware versions and that Synergy could re-flash the firmware for you, but I doubt that option still exists. I think it may have been mentioned that there was no way to update the firmware outside of the factory. That is what I remember. -Rex On 11/7/2012 5:05 AM, Azelio Boriani wrote: Never found an Oncore firmware file... can you point me to anyone of them? I'm curious to see one. On Wed, Nov 7, 2012 at 1:30 PM, Bob Campli...@rtty.us wrote: Hi There were a *lot* of firmware updates to the Oncores. I don't know if the re-flash images are still out there or not. If they are, it wouldn't hurt to upgrade the card. I don't think it will fix your problem, but it won't hurt either. Bob On Nov 7, 2012, at 1:06 AM, Ed Palmered_pal...@sasktel.net wrote: Hi Mike, My unit has the standard 6 channel VP. In fact, here's the ID message: COPYRIGHT 1991-1995 MOTOROLA INC. SFTW P/N # 98-P39972M SOFTWARE VER # 8 SOFTWARE REV # 4 SOFTWARE DATE 13 JUL 1995 MODEL #B1121P1114 HDWR P/N # _ SERIAL # SSG0239632 MANUFACTUR DATE 7H18 OPTIONS LISTIB I understand that the 'B1' start to the model number means that it's quite old. I don't remember if I ever did a full reset so I just did one. We'll see what happens. Thanks, Ed On 11/6/2012 10:20 PM, Mike S wrote: On 11/6/2012 2:59 PM, Ed Palmer wrote: But if this is a firmware issue, shouldn't there be lots of Z3801As with this problem? I suspect that there's a fault with my unit, but I can't imagine what. Does your unit by chance have an 8 channel Oncore VP instead of the stock 6 channel one? Also, have you tried a full reset (:system:preset)? ___ 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] Z3801A Problem
Hi They did indeed exist. I haven't seen one for 10 years or so. Bob On Nov 7, 2012, at 7:30 AM, Bob Camp li...@rtty.us wrote: Hi There were a *lot* of firmware updates to the Oncores. I don't know if the re-flash images are still out there or not. If they are, it wouldn't hurt to upgrade the card. I don't think it will fix your problem, but it won't hurt either. Bob On Nov 7, 2012, at 1:06 AM, Ed Palmer ed_pal...@sasktel.net wrote: Hi Mike, My unit has the standard 6 channel VP. In fact, here's the ID message: COPYRIGHT 1991-1995 MOTOROLA INC. SFTW P/N # 98-P39972M SOFTWARE VER # 8 SOFTWARE REV # 4 SOFTWARE DATE 13 JUL 1995 MODEL #B1121P1114 HDWR P/N # _ SERIAL # SSG0239632 MANUFACTUR DATE 7H18 OPTIONS LISTIB I understand that the 'B1' start to the model number means that it's quite old. I don't remember if I ever did a full reset so I just did one. We'll see what happens. Thanks, Ed On 11/6/2012 10:20 PM, Mike S wrote: On 11/6/2012 2:59 PM, Ed Palmer wrote: But if this is a firmware issue, shouldn't there be lots of Z3801As with this problem? I suspect that there's a fault with my unit, but I can't imagine what. Does your unit by chance have an 8 channel Oncore VP instead of the stock 6 channel one? Also, have you tried a full reset (:system:preset)? ___ 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] Z3801A Problem
Hi GPS receivers have gotten better over the years. The early Motorola receivers were relatively deaf compared to a TBolt. A TBolt is a bit deaf compared to a LEA5-T. My bet for the actual problem is that HP is doing elevation masks and s/n detection in their firmware rather than in the receiver. Bob On Nov 5, 2012, at 10:11 PM, Ed Palmer ed_pal...@sasktel.net wrote: Hi Azelio, On 11/5/2012 4:09 PM, Azelio Boriani wrote: Very interesting... is it using the binary protocol? Yes, standard Motorola binary format. Maybe a serial link error, the binary protocol has a checksum (yes, NMEA too). Check the serial link levels with a 'scope, maybe that the Z3801 firmware waits to see some consecutive errors before actually reporting that something is wrong, meanwhile the satellite number is set to 0. The link is TTL, not RS-232. The power supply to the VP is 4V93 and the logic levels on the scope are maybe 0V2 and 4V8 so no problem there. I've tried disconnecting the 1 PPS and/or the data line from the VP to the Z3801A. The Z3801A reports the loss of 1 PPS quickly, but in either case, waits for quite a while before getting upset. I haven't been able to corrupt a message to see what effect that has, but I think it would have to be a very specific form of corruption to be accepted. In any case, although that might explain the drop to zero satellites tracked, it wouldn't explain the situation where the VP reports fewer satellites tracked than the Z3801A does. This occurs frequently. I don't know if the two situations (drop to zero and fewer satellites) are related or not. By the way, I was initially using SynTac and Z38XX to gather the data. Since I couldn't believe the results, I replaced both with a program I quickly hacked together to gather and parse the raw data from both units. The results were the same. Ed On Mon, Nov 5, 2012 at 10:38 PM, Ed Palmer ed_pal...@sasktel.net wrote: I've had a Z3801A for about a year. It's always had an issue where the number of satellites tracked will drop to zero for one or two readings and then jump right back where it was ( often at 5 or 6 satellites ). This often (but not always) affects the EFC and/or PPS and/or HUP. My Tbolt is running on the same antenna via an HP58536A splitter with no problems. I've changed cables and splitter ports with no improvement. I've also checked the power supply voltages and the frequencies of the two crystals on the Z3801A board. All are fine. I assumed that the VP was flaky so I recently pulled it out for testing and found no problems. I then tapped into the link between the VP and the Z3801A and found that the number of tracked satellites reported by the Z3801A is often less than the number reported by the VP. Specifically, I've seen the VP report 6 satellites tracked at the exact same second that the Z3801A is claiming that there are no (zero) satellites tracked. Does anyone know if there are any hidden parameters that the Z3801A is using to decide if a satellite is acceptable? I looked through the manual but I couldn't find anything. Is there a command I'm missing? Thanks, Ed ___ 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] Z3801A Problem
Hi Bob, The elevation mask is handled by the receiver, but I was wondering about the s/n or signal strength. But it seems unlikely that all the satellites would simultaneously fall below the magic threshold. In any case, I will capture the data and see if there's anything interesting. Thanks, Ed On 11/6/2012 5:55 AM, Bob Camp wrote: Hi GPS receivers have gotten better over the years. The early Motorola receivers were relatively deaf compared to a TBolt. A TBolt is a bit deaf compared to a LEA5-T. My bet for the actual problem is that HP is doing elevation masks and s/n detection in their firmware rather than in the receiver. Bob On Nov 5, 2012, at 10:11 PM, Ed Palmer ed_pal...@sasktel.net wrote: Hi Azelio, On 11/5/2012 4:09 PM, Azelio Boriani wrote: Very interesting... is it using the binary protocol? Yes, standard Motorola binary format. Maybe a serial link error, the binary protocol has a checksum (yes, NMEA too). Check the serial link levels with a 'scope, maybe that the Z3801 firmware waits to see some consecutive errors before actually reporting that something is wrong, meanwhile the satellite number is set to 0. The link is TTL, not RS-232. The power supply to the VP is 4V93 and the logic levels on the scope are maybe 0V2 and 4V8 so no problem there. I've tried disconnecting the 1 PPS and/or the data line from the VP to the Z3801A. The Z3801A reports the loss of 1 PPS quickly, but in either case, waits for quite a while before getting upset. I haven't been able to corrupt a message to see what effect that has, but I think it would have to be a very specific form of corruption to be accepted. In any case, although that might explain the drop to zero satellites tracked, it wouldn't explain the situation where the VP reports fewer satellites tracked than the Z3801A does. This occurs frequently. I don't know if the two situations (drop to zero and fewer satellites) are related or not. By the way, I was initially using SynTac and Z38XX to gather the data. Since I couldn't believe the results, I replaced both with a program I quickly hacked together to gather and parse the raw data from both units. The results were the same. Ed On Mon, Nov 5, 2012 at 10:38 PM, Ed Palmer ed_pal...@sasktel.net wrote: I've had a Z3801A for about a year. It's always had an issue where the number of satellites tracked will drop to zero for one or two readings and then jump right back where it was ( often at 5 or 6 satellites ). This often (but not always) affects the EFC and/or PPS and/or HUP. My Tbolt is running on the same antenna via an HP58536A splitter with no problems. I've changed cables and splitter ports with no improvement. I've also checked the power supply voltages and the frequencies of the two crystals on the Z3801A board. All are fine. I assumed that the VP was flaky so I recently pulled it out for testing and found no problems. I then tapped into the link between the VP and the Z3801A and found that the number of tracked satellites reported by the Z3801A is often less than the number reported by the VP. Specifically, I've seen the VP report 6 satellites tracked at the exact same second that the Z3801A is claiming that there are no (zero) satellites tracked. Does anyone know if there are any hidden parameters that the Z3801A is using to decide if a satellite is acceptable? I looked through the manual but I couldn't find anything. Is there a command I'm missing? Thanks, Ed ___ 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] Z3801A Problem
Hi My though is that you have two issues: 1) The fact that the receiver reports more sat's than the firmware. 2) The drop outs. If the firmware is fine tuning something, (like s/n or elevation) that would explain the first issue. If it's something like s/n where they may be averaging values, then a single bad packet *could* mess up their averaging and turn it all off. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Ed Palmer Sent: Tuesday, November 06, 2012 10:52 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3801A Problem Hi Bob, The elevation mask is handled by the receiver, but I was wondering about the s/n or signal strength. But it seems unlikely that all the satellites would simultaneously fall below the magic threshold. In any case, I will capture the data and see if there's anything interesting. Thanks, Ed On 11/6/2012 5:55 AM, Bob Camp wrote: Hi GPS receivers have gotten better over the years. The early Motorola receivers were relatively deaf compared to a TBolt. A TBolt is a bit deaf compared to a LEA5-T. My bet for the actual problem is that HP is doing elevation masks and s/n detection in their firmware rather than in the receiver. Bob On Nov 5, 2012, at 10:11 PM, Ed Palmer ed_pal...@sasktel.net wrote: Hi Azelio, On 11/5/2012 4:09 PM, Azelio Boriani wrote: Very interesting... is it using the binary protocol? Yes, standard Motorola binary format. Maybe a serial link error, the binary protocol has a checksum (yes, NMEA too). Check the serial link levels with a 'scope, maybe that the Z3801 firmware waits to see some consecutive errors before actually reporting that something is wrong, meanwhile the satellite number is set to 0. The link is TTL, not RS-232. The power supply to the VP is 4V93 and the logic levels on the scope are maybe 0V2 and 4V8 so no problem there. I've tried disconnecting the 1 PPS and/or the data line from the VP to the Z3801A. The Z3801A reports the loss of 1 PPS quickly, but in either case, waits for quite a while before getting upset. I haven't been able to corrupt a message to see what effect that has, but I think it would have to be a very specific form of corruption to be accepted. In any case, although that might explain the drop to zero satellites tracked, it wouldn't explain the situation where the VP reports fewer satellites tracked than the Z3801A does. This occurs frequently. I don't know if the two situations (drop to zero and fewer satellites) are related or not. By the way, I was initially using SynTac and Z38XX to gather the data. Since I couldn't believe the results, I replaced both with a program I quickly hacked together to gather and parse the raw data from both units. The results were the same. Ed On Mon, Nov 5, 2012 at 10:38 PM, Ed Palmer ed_pal...@sasktel.net wrote: I've had a Z3801A for about a year. It's always had an issue where the number of satellites tracked will drop to zero for one or two readings and then jump right back where it was ( often at 5 or 6 satellites ). This often (but not always) affects the EFC and/or PPS and/or HUP. My Tbolt is running on the same antenna via an HP58536A splitter with no problems. I've changed cables and splitter ports with no improvement. I've also checked the power supply voltages and the frequencies of the two crystals on the Z3801A board. All are fine. I assumed that the VP was flaky so I recently pulled it out for testing and found no problems. I then tapped into the link between the VP and the Z3801A and found that the number of tracked satellites reported by the Z3801A is often less than the number reported by the VP. Specifically, I've seen the VP report 6 satellites tracked at the exact same second that the Z3801A is claiming that there are no (zero) satellites tracked. Does anyone know if there are any hidden parameters that the Z3801A is using to decide if a satellite is acceptable? I looked through the manual but I couldn't find anything. Is there a command I'm missing? Thanks, Ed ___ 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] Z3801A Problem
li...@rtty.us said: If the firmware is fine tuning something, (like s/n or elevation) that would explain the first issue. If it's something like s/n where they may be averaging values, then a single bad packet *could* mess up their averaging and turn it all off. What can the firmware do if it decides that it doesn't like a satellite? The GPS receiver does the math and sends over the PPS. How would the firmware adjust that calculation to not use a particular satellite? You can set the elevation mask angle. I don't see a way to set a S/N filter. (I assume the mask angle gets passed to the GPS receiver.) You can tell it to ignore specific satellites. I assume that list gets passed to the receiver. The firmware might be able to use that mechanism for S/N filtering, but the timing seems wrong. If the S/N for a sat is too low, the firmware would have to ignore the data for that second, tell the receiver to ignore that sat, and hope the data for the next second is good. It might work if S/N only changes slowly, but I don't think that's the case for things like multipath. -- 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] Z3801A Problem
Hi At least some of the Motorola receivers passed across per satellite timing information. That would allow you to play with what you used or didn't use in the firmware. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray Sent: Tuesday, November 06, 2012 1:15 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3801A Problem li...@rtty.us said: If the firmware is fine tuning something, (like s/n or elevation) that would explain the first issue. If it's something like s/n where they may be averaging values, then a single bad packet *could* mess up their averaging and turn it all off. What can the firmware do if it decides that it doesn't like a satellite? The GPS receiver does the math and sends over the PPS. How would the firmware adjust that calculation to not use a particular satellite? You can set the elevation mask angle. I don't see a way to set a S/N filter. (I assume the mask angle gets passed to the GPS receiver.) You can tell it to ignore specific satellites. I assume that list gets passed to the receiver. The firmware might be able to use that mechanism for S/N filtering, but the timing seems wrong. If the S/N for a sat is too low, the firmware would have to ignore the data for that second, tell the receiver to ignore that sat, and hope the data for the next second is good. It might work if S/N only changes slowly, but I don't think that's the case for things like multipath. -- 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] Z3801A Problem
What can the firmware do if it decides that it doesn't like a satellite? The GPS receiver does the math and sends over the PPS. How would the firmware adjust that calculation to not use a particular satellite? Hal, Just let the firmware do what it does. The detection and adjustments can be done off-board. Not unlike what all the pros do with post-processing. Look at the Oncore @@Ha or @@Hn message -- you get the timing solution contribution for each SV. What you see in the hardware 1PPS is simply a real-time, uneducated, equally weighted mean of this calculation. It works pretty well. However, if you can apply an educated manual weighting (perhaps based on a long- or short-term history of SVN, Az/El, signal levels, std dev from mean, etc.) to each SV in the solution, it seems to me it is possible to calculate a virtual 1PPS that is more accurate than the real 1PPS. When you think about it, a static elevation mask, ignoring the role of azimuth, ignoring your antenna 2D tree profile, ignoring S/N ratios, and treating all SV in the sky as perfecty equal is simple, but dumb. Someone on the list could make a fun project to explore these algorithms to improve the performance of Oncore, TBolt, or u-blox timing receivers. I've looked into this for the Oncore and TBolt but haven't posted anything. Contact me off-line if interested. /tvb ___ 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] Z3801A Problem
In message 4b56b3dacedd407cbbec4138a519e...@vectron.com, Bob Camp writes: Hi At least some of the Motorola receivers passed across per satellite timing information. That would allow you to play with what you used or didn't use in the firmware. See also: http://phk.freebsd.dk/raga/sneak/ -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Z3801A Problem
When I look at the data that the VP is sending to the Z3801A, all I see are the Ba, Bb, and Bn commands. I don't know if any of those have enough low level information to play with. But if this is a firmware issue, shouldn't there be lots of Z3801As with this problem? I suspect that there's a fault with my unit, but I can't imagine what. I've got good signal levels. The SYST:STAT command shows levels of 200 on a 1-255 scale for some satellites. Ed On 11/6/2012 12:41 PM, Bob Camp wrote: Hi At least some of the Motorola receivers passed across per satellite timing information. That would allow you to play with what you used or didn't use in the firmware. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray Sent: Tuesday, November 06, 2012 1:15 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3801A Problem li...@rtty.us said: If the firmware is fine tuning something, (like s/n or elevation) that would explain the first issue. If it's something like s/n where they may be averaging values, then a single bad packet *could* mess up their averaging and turn it all off. What can the firmware do if it decides that it doesn't like a satellite? The GPS receiver does the math and sends over the PPS. How would the firmware adjust that calculation to not use a particular satellite? You can set the elevation mask angle. I don't see a way to set a S/N filter. (I assume the mask angle gets passed to the GPS receiver.) You can tell it to ignore specific satellites. I assume that list gets passed to the receiver. The firmware might be able to use that mechanism for S/N filtering, but the timing seems wrong. If the S/N for a sat is too low, the firmware would have to ignore the data for that second, tell the receiver to ignore that sat, and hope the data for the next second is good. It might work if S/N only changes slowly, but I don't think that's the case for things like multipath. ___ 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] Z3801A Problem
On 11/6/2012 2:59 PM, Ed Palmer wrote: But if this is a firmware issue, shouldn't there be lots of Z3801As with this problem? I suspect that there's a fault with my unit, but I can't imagine what. Does your unit by chance have an 8 channel Oncore VP instead of the stock 6 channel one? Also, have you tried a full reset (:system:preset)? ___ 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] Z3801A Problem
Hi Mike, My unit has the standard 6 channel VP. In fact, here's the ID message: COPYRIGHT 1991-1995 MOTOROLA INC. SFTW P/N # 98-P39972M SOFTWARE VER # 8 SOFTWARE REV # 4 SOFTWARE DATE 13 JUL 1995 MODEL #B1121P1114 HDWR P/N # _ SERIAL # SSG0239632 MANUFACTUR DATE 7H18 OPTIONS LISTIB I understand that the 'B1' start to the model number means that it's quite old. I don't remember if I ever did a full reset so I just did one. We'll see what happens. Thanks, Ed On 11/6/2012 10:20 PM, Mike S wrote: On 11/6/2012 2:59 PM, Ed Palmer wrote: But if this is a firmware issue, shouldn't there be lots of Z3801As with this problem? I suspect that there's a fault with my unit, but I can't imagine what. Does your unit by chance have an 8 channel Oncore VP instead of the stock 6 channel one? Also, have you tried a full reset (:system:preset)? ___ 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] Z3801A Problem
Very interesting... is it using the binary protocol? Maybe a serial link error, the binary protocol has a checksum (yes, NMEA too). Check the serial link levels with a 'scope, maybe that the Z3801 firmware waits to see some consecutive errors before actually reporting that something is wrong, meanwhile the satellite number is set to 0. On Mon, Nov 5, 2012 at 10:38 PM, Ed Palmer ed_pal...@sasktel.net wrote: I've had a Z3801A for about a year. It's always had an issue where the number of satellites tracked will drop to zero for one or two readings and then jump right back where it was ( often at 5 or 6 satellites ). This often (but not always) affects the EFC and/or PPS and/or HUP. My Tbolt is running on the same antenna via an HP58536A splitter with no problems. I've changed cables and splitter ports with no improvement. I've also checked the power supply voltages and the frequencies of the two crystals on the Z3801A board. All are fine. I assumed that the VP was flaky so I recently pulled it out for testing and found no problems. I then tapped into the link between the VP and the Z3801A and found that the number of tracked satellites reported by the Z3801A is often less than the number reported by the VP. Specifically, I've seen the VP report 6 satellites tracked at the exact same second that the Z3801A is claiming that there are no (zero) satellites tracked. Does anyone know if there are any hidden parameters that the Z3801A is using to decide if a satellite is acceptable? I looked through the manual but I couldn't find anything. Is there a command I'm missing? Thanks, Ed ___ 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] Z3801A Problem
Hi Azelio, On 11/5/2012 4:09 PM, Azelio Boriani wrote: Very interesting... is it using the binary protocol? Yes, standard Motorola binary format. Maybe a serial link error, the binary protocol has a checksum (yes, NMEA too). Check the serial link levels with a 'scope, maybe that the Z3801 firmware waits to see some consecutive errors before actually reporting that something is wrong, meanwhile the satellite number is set to 0. The link is TTL, not RS-232. The power supply to the VP is 4V93 and the logic levels on the scope are maybe 0V2 and 4V8 so no problem there. I've tried disconnecting the 1 PPS and/or the data line from the VP to the Z3801A. The Z3801A reports the loss of 1 PPS quickly, but in either case, waits for quite a while before getting upset. I haven't been able to corrupt a message to see what effect that has, but I think it would have to be a very specific form of corruption to be accepted. In any case, although that might explain the drop to zero satellites tracked, it wouldn't explain the situation where the VP reports fewer satellites tracked than the Z3801A does. This occurs frequently. I don't know if the two situations (drop to zero and fewer satellites) are related or not. By the way, I was initially using SynTac and Z38XX to gather the data. Since I couldn't believe the results, I replaced both with a program I quickly hacked together to gather and parse the raw data from both units. The results were the same. Ed On Mon, Nov 5, 2012 at 10:38 PM, Ed Palmer ed_pal...@sasktel.net wrote: I've had a Z3801A for about a year. It's always had an issue where the number of satellites tracked will drop to zero for one or two readings and then jump right back where it was ( often at 5 or 6 satellites ). This often (but not always) affects the EFC and/or PPS and/or HUP. My Tbolt is running on the same antenna via an HP58536A splitter with no problems. I've changed cables and splitter ports with no improvement. I've also checked the power supply voltages and the frequencies of the two crystals on the Z3801A board. All are fine. I assumed that the VP was flaky so I recently pulled it out for testing and found no problems. I then tapped into the link between the VP and the Z3801A and found that the number of tracked satellites reported by the Z3801A is often less than the number reported by the VP. Specifically, I've seen the VP report 6 satellites tracked at the exact same second that the Z3801A is claiming that there are no (zero) satellites tracked. Does anyone know if there are any hidden parameters that the Z3801A is using to decide if a satellite is acceptable? I looked through the manual but I couldn't find anything. Is there a command I'm missing? Thanks, Ed ___ 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] Z3801A Problem
azelio.bori...@screen.it said: Very interesting... is it using the binary protocol? Maybe a serial link error, the binary protocol has a checksum (yes, NMEA too). Check the serial link levels with a 'scope, maybe that the Z3801 firmware waits to see some consecutive errors before actually reporting that something is wrong, meanwhile the satellite number is set to 0. That seems unlikely, but I've been surprised before. I have two Z3801As using the same antenna which is not in a good location. They both go into holdover at the same time about once per day. (Occasionally, it's only one.) I don't have any data on the number of satellites. I assume it goes to 0, but I don't know how long it stays there. It looks like a spike on the scale of 1 sample per minute. I've been assuming it was something like multipath from an airplane. I'm roughly 20 miles from the San Francisco airport. I'm not on a main flight path, but it's not uncommon to see a large plane go over reasonably low. I assume it's merging into the landing pattern. Does anybody know how to find out if there are any planes near a specific location, and if so how to get the flight path with good timings? The HP driver in the ntp reference package logs a line like this every minute (actually 64 seconds): 56237 776.033 127.127.26.1 T2201211060012573001036 64 0 56237 840.033 127.127.26.1 T220121106001401300102D 64 0 56237 904.044 127.127.26.1 T2201211060015053001032 64 0 56237 968.034 127.127.26.1 T2201211060016093001037 64 0 The 64 0 on the end are counters I've added to my local copy. The 64 is the number of good T2 messages. The 0 is the number of messages with errors. One of the columns in the T2 chunk is the FFOM, another is the TFOM. (I'd have to look it up.) If I was to add some more info to that line, what would you want? EFC and number of satellites are a couple of obvious ones. EFC probably doesn't change very often or fast. One sample per minute is probably good enough. For the number of satellites, we might want both the min and max, and even the count at that level. -- 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] Z3801A Problem
On 11/5/2012 11:27 PM, Hal Murray wrote: azelio.bori...@screen.it said: Very interesting... is it using the binary protocol? Maybe a serial link error, the binary protocol has a checksum (yes, NMEA too). Check the serial link levels with a 'scope, maybe that the Z3801 firmware waits to see some consecutive errors before actually reporting that something is wrong, meanwhile the satellite number is set to 0. That seems unlikely, but I've been surprised before. I have two Z3801As using the same antenna which is not in a good location. They both go into holdover at the same time about once per day. (Occasionally, it's only one.) I don't have any data on the number of satellites. I assume it goes to 0, but I don't know how long it stays there. It looks like a spike on the scale of 1 sample per minute. I've been assuming it was something like multipath from an airplane. I'm roughly 20 miles from the San Francisco airport. I'm not on a main flight path, but it's not uncommon to see a large plane go over reasonably low. I assume it's merging into the landing pattern. Does anybody know how to find out if there are any planes near a specific location, and if so how to get the flight path with good timings? The HP driver in the ntp reference package logs a line like this every minute (actually 64 seconds): 56237 776.033 127.127.26.1 T2201211060012573001036 64 0 56237 840.033 127.127.26.1 T220121106001401300102D 64 0 56237 904.044 127.127.26.1 T2201211060015053001032 64 0 56237 968.034 127.127.26.1 T2201211060016093001037 64 0 The 64 0 on the end are counters I've added to my local copy. The 64 is the number of good T2 messages. The 0 is the number of messages with errors. One of the columns in the T2 chunk is the FFOM, another is the TFOM. (I'd have to look it up.) If I was to add some more info to that line, what would you want? EFC and number of satellites are a couple of obvious ones. EFC probably doesn't change very often or fast. One sample per minute is probably good enough. For the number of satellites, we might want both the min and max, and even the count at that level. EFC would be interesting to see. When the problem occurs on my Z3801A, the EFC might do nothing, or spike, or jump and stay at the new value, or jump and recover to the original value. HUP would also be good to record to watch for a degradation in that value. Ed ___ 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.
