Specifications

48 Z-Family Technical Reference Manual
corrections are automatically processed by the receiver. For diagnostic purposes, the
RTCM messages can be output in an ASCII format on the rover side via the MSG
command (See “MSG: Base Station Message” on page 166).
On initial power-up or after use of the $PASHS,RST reset to defaults command, the
receiver default automatic differential mode is OFF, and the default is 60 seconds for
the maximum age of an RTCM differential correction above which it will not be used.
If the automatic mode is not enabled by the $PASHS,RTC,AUT,Y set command and
the differential correction data is older than the maximum age specified by the
$PASHS,RTC,MAX set command, the receiver does not return antenna position data.
In automatic mode, if no differential correction data is received and the age of data is
older than the specified maximum age, the receiver does return the uncorrected raw
position.
RTCM 104 Format, Version 2.2
When the receiver is used as a reference station and the RTCM and RTK Base options
are enabled, it computes differential corrections for up to 12 satellites, converts those
corrections to RTCM format, and transmits the converted messages via its serial
ports. It can generate message types 1, 2, 3, 6, 16, 18, 19, 20, 21, 22 as detailed in
Table 3.15.
Table 3.15: RTCM Message Types
GPS
Message
Type
Contents of Message
1 Differential GPS corrections
2 Delta differential corrections
3 Reference station parameters in
WGS 84
6 Null frame
16 Special GPS text message
18 RTK carrier phase
19 RTK pseudo-ranges
20 RTK carrier phase corrections
21 RTK code phase (pseudo-range)
corrections
22 Extended reference station
parameter