Campbell Scientific GPS16X-HVS GPS Receiver - Manual (Page 32)

Appendix B. CR23X Wiring and Programming
20: Sample (P70) ^20303
1: 4
Reps
2: 2 Loc [ LatDegMin ]
; Write elevation in meters
21: Sample (P70) ^32246
1: 1
Reps
2: 10 Loc [ Elevation ]
; Set resolution low
22: Resolution (P78)
1: 0
Low Resolution
; Write the number of satellites in view
23: Sample (P70) ^1910
1: 1
Reps
2: 7 Loc [ NumSats ]
; Reset the the GPS quality number
24: Z=F x 10^n (P30)
1: -1
F
2: 00 n, Exponent of 10
3: 6 Z Loc [ Quality ]
25: End (P95)
26: End (P95)
End Program
B.3 Troubleshooting
The first step is to verify the GPS16X outputs with a terminal program (see
Section 6.1). The second step is to verify that it really does not work. With the
GPS16X-HVS running and the datalogger program running, look at the input
location for GPS Quality Number. This location will show a one when the
GPS16X-HVS output is picked up by the datalogger. The input location for
parsed time and position are good locations to check. The location for seconds
should update every time the GPS data is updated.
If the GPS time and position data are not shown in the input locations, check
the communication cable wiring.
If the GPS16X-HVS data is not correct every program table execution but
correct sometimes, check the P15 time-out. It may need a longer time-out.
Also check the P15 maximum number of characters to receive, usually 100 is
enough. Check the P15 termination character; it should be set to 42 (*). The
termination character should also work if set to 13 or 10. Also check the
buffering and filter. Buffering should be turned off by indexing parameter 2.
For P15 to properly read the $GPGGA string, P15 must be executing while the
$GPGGA string starts and finishes. The P15 time-out needs to be long enough
to pick up the string. The string is output once a second. If P15 starts to
execute while the GPS16X-HVS is sending the string, P15 must wait until the
string is sent again plus the amount of time it takes to send the string. It
shouldn’t need more than 1.5 seconds. P15 time-out is in units of 0.01
seconds, 100 = 1 second. A longer time-out will force the datalogger to wait
until the time-out has expired or the termination character is received or the
maximum number of characters are received. If the data in input locations
B-8