Greetings all,
Here’s an odd issue.
One of my CMM Micros is loosing its track on its satellites. The CMM Micro can still “see” the sats, but not track them.
GPS Page on CMM:
GPS Status
SYNC Pulse Status: No SYNC
Tracking Mode: Acquiring Satellites
GPS Time: 20:04:12
GPS Date: 12/28/2005
Satellites Tracked: 0 <=======-------------------------
of Satellites Visible: 9 <=====---------------------------
Height: 404 meters
Antenna Connection: Over Current <========-------------------
Latitude: N45 XX.XXXX (edit)
Longitude: W84 XX.XXXX (edit)
Invalid Msg: 0
Restart Count: 0
GPS Receiver Information
COPYRIGHT 1991-2004 MOTOROLA INC.
SFTW P/N # XX-XXXXXXX (edit)
SOFTWARE VER # 2
SOFTWARE REV # 0.1
SOFTWARE DATE JUN 09 2004
MODEL # P283T12T18
HWDR P/N # 2
SERIAL # XXXXXX (edit)
MANUFACTUR DATE 4F28
-EOF-
As you can see, the GPS is functioning in all aspects save sync. I’m getting an accurate position coordinate, accurate time and date, sats are visible, accurate info on the receiver is displayed, but tracking zero sats.
According to the log in the CMM and the APs off of it, the GPS will lose sync then find it again after several seconds to 2 or 3 minutes. This will repeat several times, then it will lose sync and it won’t come back no matter what I do (software reboot, hard reboot, etc).
Event Log:
06:16:54pm : Tue Dec 27 2005 : File gps.c : Line 435 GPS Date/Time Set
06:17:12pm : Tue Dec 27 2005 : File gps.c : Line 676 GPS SYNC Pulse Detected
09:59:20am : Wed Dec 28 2005 : File gps.c : Line 685 GPS SYNC Pulse Lost
09:59:28am : Wed Dec 28 2005 : File gps.c : Line 676 GPS SYNC Pulse Detected
09:59:36am : Wed Dec 28 2005 : File gps.c : Line 685 GPS SYNC Pulse Lost
10:02:48am : Wed Dec 28 2005 : File gps.c : Line 676 GPS SYNC Pulse Detected
10:15:20am : Wed Dec 28 2005 : File gps.c : Line 685 GPS SYNC Pulse Lost
10:15:28am : Wed Dec 28 2005 : File gps.c : Line 676 GPS SYNC Pulse Detected
10:16:48am : Wed Dec 28 2005 : File gps.c : Line 685 GPS SYNC Pulse Lost
10:53:12am : Wed Dec 28 2005 : File gps.c : Line 676 GPS SYNC Pulse Detected
06:16:20pm : Wed Dec 28 2005 : File gps.c : Line 685 GPS SYNC Pulse Lost
-EOF-
Facts:
The CMM is on the tower (130-ish feet), and has an awesome view.
The GPS cable is 10 feet long.
This Canopt 900 deployment has opperated flawlessly for about 8 months.
The tower is also used as a CB radio repeater (frequency is not ISM 900, but otherwise unknown)
The upper parts of the tower may have minor ice buildup, I have not climbed to confirm.
So…
Aside from the general “what the heck is going on?” question,
Could potiental ice on the GPS antenna cause this?
What does the “antenna connection” status of “over current” mean?
Any other ideas of what is wrong?
The KB article on the GPS antenna was none too helpful: http://motorola.canopywireless.com/supp … d=228&c=12
Thanks,
Is this one any better?
http://motorola.canopywireless.com/supp … d=247&c=14
I would try the suggestions in the article to measure the voltage and current. It sounds like it could be an issue with the cable. You might want to make sure that there isn’t any corrosion and that it is tight.
Awesome thanks.
Looks like its time to dust off my harnes.