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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.
DDC2-RS
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.
DDC4-RS
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.
DDC2/4-RS / DDC2/4-RS-24
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.
