Trimble Outdoors THUNDERBOLT 64057-00-ENG - Manual (Page 70)

A Trimble Standard Interface Protocol
68 Trimble ThunderBolt E GPS Disciplined Clock User Guide
Command Packet 0x8E-A3: Issue Oscillator Disciplining Command
Use command packet 0x8E-A3 to issue an oscillator disciplining command. The
receiver responds with packet 0x8F-A3 in the same format as packet 0x8E-A3.
Command Packet 0x8E-A4: Test Modes
ThunderBolt E provides a test mode of operation that allows the user to set the time
and UTC parameters. Packet 0x8F-AC provides a status bit (minor alarm bit 8) to warn
the user that ThunderBolt E is operating in a test mode. The receiver replies with
response packet 8F-A4.
Note – Test mode 3 does not actually cause the receiver to enter a test mode, but instead
provides a means for the user to send UTC parameters to the receiver that will be used in
test mode 1.
Byte Item Type Value Description
0 Subcode UINT8 0xA3
1 Disciplining Command UINT8 0 Place PPS on time (jam sync)
1 Transition to recovery state
2 Transition to manual holdover
3 Transition from manual holdover
4 Disable oscillator disciplining
5 Enable oscillator disciplining.
Test mode Data field Description
0 Test mode Set this field to 0 to exit test mode and return the receiver to
normal operations. A reset or power cycle will also cause the
receiver to exit test mode.
1 Test mode Setting this field to 1 tells the receiver to enter the user time test
mode. The receiver will set the time to the week number and
TOW sent with this packet. The receiver will then increment this
time once per second. The time in packet 8F-AB will show the
user test time, but all other packets that have time fields will be
unaffected.
Week
number This field contains the week number for the user time test mode.
Time-of-
Week This field contains the TOW for the user time test mode.
3 Note – For a more detailed description of UTC parameters, see GPS SPS Signal
Specification
Test Mode Setting this field to 3 tells the receiver that the following fields
contain the user UTC parameters that are to be used while in test
mode 1.
A_0 This field is the fractional second offset of GPS from UTC at the
reference time in seconds.
A_1 This field is the rate of change of fractional second offset of GPS
from UTC in seconds/second.
delta_t_LS Current integer leap seconds.