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Acutime 2000 Connections

TSIP timing packets 8F-0B, 8F-AB and 8F-AC (which work together as a pair of packets) or 8F-AD can be enabled on Port B using command packet 8E-A5. These packets are sent within 30 milliseconds after the PPS pulse when enabled.

By default, the Acutime 2000 automatically sends a variety of satellite data packets on Port B that you may not need. You can disable these automatic output packets with command packet 8E-A5 so that only the timing packets are sent. You can also choose to receive these timing packets on Port A, which serves as a dedicated transmit port for timing packets, and use Port B to send commands and receive satellite data.

Port B can also be configured to transmit NMEA packets, but these packets are not guaranteed to be sent within 30 milliseconds after the PPS output.

Port A

By default, the Port A receive line is used to receive external event inputs as described below; however, Port A can also receive serial RTCM (differential corrections.) When you enable RTCM messages on Port A (by sending command packets on Port B), the event input mechanism is automatically disabled. When RTCM messages are off (the default state), the event input mechanism is automatically enabled.

4.3.4Event Input

The Acutime 2000 accepts an external event input in the form of an RS-422 pulse. The external event pulse input is supported on Port A (pins #6 and #7). The Acutime 2000 transmits a TSIP time packet (8Fx0B or 8FxAD) in response to the event input. The TSIP packet increments the event count field for each event received.

The event time stamp is generated within 320 nanoseconds of arrival at the Acutime 2000’s interface connector. The precision of the time stamp is subject to Selective Availability.

Acutime 2000 Synchronization Kit User Guide

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Trimble Outdoors AcutimeTM2000 Synchronization Kit, Part Number 45005-00-ENG manual Event Input, Port a