Trimble Outdoors THUNDERBOLT 64057-00-ENG - Manual (Page 52)

A Trimble Standard Interface Protocol
50 Trimble ThunderBolt E GPS Disciplined Clock User Guide
Note – Bytes 0 through 4 are part of the application layer of the firmware, while bytes 5
through 9 are part of the GPS core layer of the firmware.
Report Packet 0x46: Receiver Health
This packet provides receiver health status. The receiver sends this packet in response
to packet 0x26.
Report Packet 0x47: Signals Levels for Tracked Satellites
This packet provides received signal levels for all satellites currently being tracked or
on which tracking is being attempted (i.e., above the elevation mask and healthy
according to the almanac). The receiver sends this packet in response to packet 0x27 or
automatically as listed in the Automatic Output Packets section. The data format is
shown below. Up to 12 satellite number/signal level pairs may be sent as indicated by
the count field. Signal level is normally positive. If it is zero then that satellite has not
yet been acquired. If it is negative then that satellite is not currently in lock. The
absolute value of signal level field is the last known signal level of that satellite.
Note – The signal level provided in this packet is a linear measure of the signal strength
after correlation or de-spreading. Units are either AMU or dB-Hz as controlled by packet
0x35.
Byte Item Type Value Meaning
0 SV Fix Status bit field 0x00 Doing fixes
0x01 Do not have GPS time yet
0x03 PDOP too high
0x0C Bad 1 SV
0x08 No usable SV's
0x09 Only 1 usable SV
0x0A Only 2 usable SVs
0x0B Only 3 usable SVs
0xBB Over-Determined Clock mode
1 Antenna Fault
status bit field Bit 0
Bits 1-3
Bits 4-7
0 if Warm start, 1 otherwise unused
0000 = no fault
0001 = antenna circuit open
0011 = antenna circuit short
Byte Item Type
0 Count UINT8
1 Satellite number 1 UINT8
2-5 Signal level 1 Single
6 Satellite number 2 UINT8
7-10 Signal level 2 Single
(etc.) (etc.) (etc.)