Ross 4500DR-104-07, User Manual, Page: 138 / 161

138 • GPS Option SRG-4500 User Guide (v7.0)
Simplified GPS Flowchart
Figure 16.9 Phasing to GPS Flowchart
YES
Found
GPS
Time?
Lost for
>1 hour?
NO
NO
Power On
Clear 25Hz Lock,
Clear 29.97Hz Lock,
Clear 30Hz Lock
YES
Search for
GPS Frequency
Is the
Error
<1ppm?
YES NO
Is the
Error
<0.1ppm?
YES NO
Set TLock
Set TiLock
FrameCount
= 25Hz
Phase Lock
Point?
YES NO
FrameCount
= 30Hz
Phase Lock
Point?
YES NO
Set 30Hz Lock
FrameCount
= 29.97Hz
Phase Lock
Point?
YES NO
Set 29.97Hz Lock
Set 25Hz Lock
Search for GPS Time
Set TaLock