Trimble Outdoors THUNDERBOLT 64057-00-ENG - Manual (Page 47)

Trimble ThunderBolt E GPS Disciplined Clock User Guide 45
Trimble Standard Interface Protocol A
Command Packet 0x32 Data Format (single precision)
Command Packet 0x32 Data Format (double precision)
Command Packet 0x34: Satellite Selection For One-Satellite Mode
This packet allows the user to control the choice of the satellite to be used for the one-
satellite time-only fix mode. This packet contains one byte. If the byte value is 0, the
GPS receiver automatically chooses the best satellite. This automatic selection of the
best satellite is the default action, and the GPS receiver does this unless it receives this
packet. If the byte value is from 1 to 32, the packet specifies the PRN number of the
satellite to be used.
Command Packet 0x35: Set or Request I/O Options
This packet requests the current I/O option states and allows the I/O option states to
be set as desired.
To request the option states without changing them, the user sends this packet with
no data bytes. To change any option states, the user includes 4 data bytes with the
values. The I/O options, their default states, and the byte values for all possible states
are shown below. These options can be set into non-volatile memory with the
0x8E-4C-04 command. The GPS receiver returns packet 0x55.
The following abbreviations apply:
• ALT (Altitude)
• ECEF (Earth centered, Earth-fixed)
• XYZ (Cartesian coordinates)
• LLA (latitude, longitude, altitude)
• HAE (height above ellipsoid)
• WGS-84 (Earth model (ellipsoid))
• MSL geoid (mean sea level)
Byte Item Type Units
0-3 Latitude Single Radians, (+ for north, - for south)
4-7 Longitude Single Radians, (+ for east, - for west)
8-11 Altitude Single Meters
Byte Item Type Units
0-7 Latitude Double Radians, (+ for north, - for south)
8-15 Longitude Double Radians, (+ for east, - for west)
16-23 Altitude Double Meters