Lathem DDC4 Manual De Usuario
Page 53
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 2
nd
cable pair, if the
distance is less than 200ft; else, power is provided locally by a 9vAC Power Adapter.