Figure C-7

RS-232 Cable for Permanent Connection to the Communications Terminal Block

RS-485—Terminal block pair for RS-485 communications with an IBM-compatible computer running the optional Lathem MasterLink programming software and SWIFT (RS-485 to RS-232 converter).

MODEM—Modular connector for modem use. The optional internal modem can be used to dial out to the Atomic Clock at Fort Collins, Colorado, USA, or for a remote site using the optional Lathem MasterLink programming software.

Wiring the DDC4R Communications Terminals

The DDC4R communications terminals on the communications terminal block include:

SYNC IN—Terminal block pair used to receive RS-485 synchronization from another Dukane master product or radio synchronization device, or to transmit the 24A715/M synchronization commands to up to 30 RS-485 devices, including master and wall clocks.

SYNC OUT—Terminal block pair used to buffer and repeat a received RS-485 synchronization signal, or to transmit the 24A715/M synchronization commands to up to 30 additional RS-485 devices.

Notes:

When first powered on, the 24A715/M monitors the SYNC IN line to determine if it should be a master or a slave. If it does not receive a time update for 15 minutes,

it assumes it is a master and starts transmitting the time signal on the RS-485 synchronization line every minute. It will re-evaluate its master/slave status every day at the 00:00 hour.

When setting up the master/slave system, make sure you apply power to the master first, and connect the other 24A715/M to the SYNC OUT port on that clock.

24A715/24A715M Master Clock Installation Manual

C-5