User's Manual

Confidential & Proprietary 41/139
Figure 4.17 – OEU Inner Look
No. Unit Description Remark
1 DOU
Donor Optic Unit
Convert TX RF signals into optical signals;
Convert RX optical signals into RF signals;
Provide up to four optical ports per DOU
Max 2ea
2 EWDM
Expansion Wavelength Division Multiplexer
Convert TX optical signals into RF signals;
Convert RX RF signals into optical signals;
Compensate for optical cable loss with ODU
3 ECPU
Expansion Central Processor Unit
Control and monitoring system status
Control and monitoring with RS232
Relay state values of ROU to BIU
4 EPSU
Expansion Power Supply Unit
Input power: DC -48V, Output power: 9V, 6V
5 ERFM
Expansion Radio Frequency Module
Regenerate TX signals and transmit FSK modem
signals;
Regenerate RX signals and receive FSK modem signals
6 Shelf 19” rack, 2U
4.3.4 Function by unit
1) Donor Optic Unit (DOU)
DOU is the same as the module used for ODU.