Installation guide

Model 820 Control Unit
Behind the removable front panel of the Model 820 control unit is one line/voice terminal
module that accommodates 2 outside lines and 5 voice terminals. The Model 820 control unit
can accommodate up to four line/voice terminal modules for a maximum of 8 outside line
jacks and 20 voice terminal jacks (for more information on available types of modules, see
page 12). Positions reserved for additional modules have protective plastic covers. Model 820
has three horizontal slots on the right side for the cartridges available to expand the MERLIN
system’s capabilities.
Voice
terminal jacks
Cartridge slots
Outside
line jacks
Physical Features of the Model 820 Control Unit
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5
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3
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16
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