Trimble Standard Interface Protocol

A

A.8 Low-Latency Timing Packets

The Ace UTC and Acutime 2000 feature a sequence of high-priority timing super packets, which are output within a bounded period of time after the PPS. The LLT packets offer an advanced data interface for applications requiring accurate data reports in a time constrained environment.

On Acutime 2000 and Ace UTC, the first super packet will start transmission no later than 15 – 25 ms after the PPS transition.

The super packets which meet the LLTP criteria are in the table below. The packets are listed in order of output priority. Output of each packet can be turned on/off by using the mask in packet 8E-A5, but the output order cannot be changed.

The packets may also be requested, please refer to the specific packet documentation for details.

Table A-10 Low-Latency Timing Packets

LLTP Packet ID

Description

Request Packet ID

 

 

 

8F-AB

Primary Timing

8E-AB

 

 

 

8F-AC

Supplemental Timing

8E-AC

 

 

 

8F-AD

Primary UTC Time

8E-AD

 

 

 

8F-0B

Comprehensive Time and Position

8E-0B

 

 

 

The receiver will output all other TSIP packets after the transmission of LLTP packet sequence is complete.

!Note – Only the first packet will meet the LLTP specification. All other LLTP packets will be output immediately after the first LLTP packet completes.

A-10

Acutime 2000 Synchronization Kit User Guide

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Trimble Outdoors Part Number 45005-00-ENG, AcutimeTM2000 Synchronization Kit Table A-10 Low-Latency Timing Packets