Optimus EDC-1000 Series Instruction Manual page 23

2.2. Functionality of main unit's rear panel
(5) 18VDC Power input.
(6) Power Fuse.
(7) LINK 1 ~ 3: Connections for the three lines of conference units.
(8) L.Speaker: Master volume control integrated in the conference speakers units.
(9) Aux output connector.
(10) RS-232 connector:
Pin2: Data Transmission (Tx).
Pin3: Data Reception (Rx).
Pin5: GND.
EDC-1000 Version 2
EDC-1000 SERIES
Conference System
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