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Digital Display Wall Clock Guide

Specifications

Appendix E - LTR-GPS Satellite Receiver / Clock Synchronizer

Lathem’s LTR-GPS is a Global Positioning Satellite receiver using 12-channels to access the accurate date and time signal transmitted each second by 24 satellites in geosynchronous orbit around the globe.

The package includes an amplified GPS Antenna, which must be mounted out-doors or beneath a roof sky- light, facing skyward. An integrated cable links the Antenna to the LTR-GPS Receiver Module, which should be mounted in-doors.

The Receiver Module verifies and reformats the received satellite data, and offers multiple synchronization protocol outputs:

The RS-485 Output can directly synchronize up to 31 Lathem time products, up to 4000ft away, over a single twisted-pair from a user-provided Cat-3 or Cat-5 cable. The length of cable and number of synchronized devices can be further increased using Lathem’s “SWIFT485+” RS-485 Converter / Repeater. The supported products include:

LTR-0

Master Clock 1-Clock Ctl

DWA-S

Sonochron 1-Bell Ckt

LTR4-512

Master Clock 1-Clk + 2-Ckt

LTR8-512

Master Clock 1-Clk + 6-Ckt

LTR8-512M

Master Clock w/ Modem

DDC2-RS

2” Digital Wall Clock 115v

DDC2-RS-24

2” Digital Wall Clock 24v

DDC4-RS

4” Digital Wall Clock 115v

DDC4-RS-24

4” Digital Wall Clock 24v

An included RS-232 interface provides a periodic “Time Stamp” transmission, “MM-DD-YYYY HH:MM:SS cr”, for use by computing systems having custom software to incorporate accurate date and time records in their applications: 9600,N,8,1. Use of this option requires Lathem cable, Part No. SAE0370, to be ordered separately.

Simple DIP-Switch set-up enables the installer to specify local Time Zone, Daylight Savings Time corrections, and output formats. An LED indicator shows Signal Reception / Protocol Mode.

The LTR-GPS may receive its power from an LTRx-512-series Master Clock, using 2nd cable pair, if the distance is less than 200ft; else, power is provided locally by a 9vAC Power Adapter.

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Lathem DDC4, DDC2 manual Appendix E LTR-GPS Satellite Receiver / Clock Synchronizer, Dwa-S