Acutime 2000 Synchronization Kit User Guide A-27
ATrimble Standard Interface Protocol
0x2E Command Packet 2E
GPS Time Command
This packet provides the approximate GPS time of week and the
week number to the GPS receiver. The GPS receiver returns packet
4E. The data format is shown below. The GPS week number
reference is Week # 0 starting January 6, 1980. The seconds count
begins at the midnight which begins each Sunday morning.
This packet is ignored if the receiver has already calculated the time
from tracking a GPS satellite.
0x2F Command Packet 2F
UTC Parameters Request
This packet requests the current UTC-GPS time offset (leap seconds).
The packet has no data. The receiver returns packet 4F.
0x31 Command Packet 31
Accurate Initial Position (XYZ Cartesian ECEF)
Command
This packet is identical in content to packet 23. This packet provides
an initial position to the GPS receiver in XYZ coordinates. However,
the GPS receiver assumes the position provided in this packet to be
accurate. This packet is used for satellite a cquisition aiding in systems
where another source of position is available and in time transfer
(one-satellite mode) applications. For acquisition aiding, the position
provided by the user to the GPS receiver in this packet should be
accurate to a few kilometers. For high-accuracy time transfer,
position should be accurate to a few meters. TRAIM flags come on if
this position is not accurate enough.
Table A-21 Command Packet 2E
Byte Item Type Units
0-3 GPS time of week Single seconds
4-5 GPS week number Integer weeks