Lathem DDC2, DDC4 Configuring RS485 Communications - DDC2/4-RS Series , Battery Usage

Page 7 Digital Display Wall Clock Guide

Configuring RS485 Communications - DDC2/4-RS Series

When multiple DDC2 (4)-RS Series Wall Clocks are installed as slave units to either the Lathem LTR4-

512 or LTR8-512 Master, LTR0 Mini-Master, Terminal Manager Software or the OMNI:CHRON Time

Clock, the last clock on the line must have a shunt installed over both pins at position J2 (see figure 2, page

9). When shipped, the shunt is placed over only one pin of position J2 in an "open" setting. It is necessary

to place the shunt over both pins of position J2 and create a "closed" setting for the last clock on the line.

Remove the four phillips head screws from the left or the right end cap and remove. Slide the lens and

circuit board assembly out of the case. Place the lens aside and carefully flip the circuit board assembly

over and lay it face down on a clean, smooth work surface. Locate position J2 on the left, upper side of the

back of the circuit board assembly (see figure 2, page 9). Lift the shunt straight up off the single pin of

position J2. Align the shunt to cover both pins of position J2 and press firmly into place. Slide the lens and

circuit board assembly back into the case, replace the end cap, and secure with the four phillips head

screws.

Remove the two phillips head screws from the left or the right end cap and remove. Slide the front panel

assembly out of the case. Carefully flip the front panel assembly over and lay it face down on a clean,

smooth work surface. Locate position J2 on the left, upper side of the back of the front panel. (See figure 2,

page 9) Lift the shunt straight up off the single pin of position J2. Align the shunt to cover both pins of

position J2 and press firmly into place. Slide the front panel display back into the case, replace the end cap

and secure with the two phillips head screws.

Note: Only the LAST clock on the line needs position J2 "closed". Leave all other clocks "open".

Battery Usage - DDC2 / DDC4 Series

Depending on the secondary selection type, the 9-Volt alkaline battery (not included) performs different

functions and may be required for proper operation.

When used as a secondary type clock the 9-Volt alkaline battery (not included) will retain the time that the

power failure occurred, although the display will go blank. When power is restored, correction signals from

the master clock will advance the wall clock to the proper time. When used as a secondary type clock in

systems that do not provide a 12-Hour correction signal, the 9-Volt alkaline battery (not included) is

required for proper operation. Without the 9-Volt alkaline battery (not included), the wall clock will reset to

12:00 AM after power resumes and will not receive the proper signal from the master clock to fully correct.