Trimble Outdoors AcutimeTM2000 Synchronization Kit manual 0x2E 0x2F 0x31, GPS Time Command

A Trimble Standard Interface Protocol

0x2E

0x2F

0x31

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.

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

This packet is ignored if the receiver has already calculated the time from tracking a GPS satellite.

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.

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 acquisition 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.

Acutime 2000 Synchronization Kit User Guide A-27