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100BaseFX Ethernet Port Connection
The concept behind the SC port and cable is quite straightforward. Suppose you are connecting
devices I and II. Contrary to electrical signals, optical signals do not require a circuit in order to
transmit data. Consequently, one of the optical lines is used to transmit data from device I to
device II, and the other optical line is used transmit data from device II to device I, for full-duplex
transmission.
All you need to remember is to connect the Tx (transmit) port of device I to the Rx (receive) port
of device II, and the Rx (receive) port of device I to the Tx (transmit) port of device II. If you
make your own cable, we suggest labeling the two sides of the same line with the same letter
(A-to-A and B-to-B, as shown below, or A1-to-A2 and B1-to-B2).
SC-Port Pinouts
SC-Port to SC-Port Cable Wiring
Tx
Rx
A
A
B
B
Cable Wiring
A
A
B
B
ATTENTION
This is a Class 1 Laser/LED product. To avoid causing serious damage to your eyes, do not stare
directly into the Laser Beam.
Redundant Power Inputs
Both power inputs can be connected simultaneously to live DC power sources. If one power
source fails, the other live source acts as a backup, and automatically supplies all of MOXA
EtherDevice Switch’s power needs.
Alarm Contact
MOXA EtherDevice Switch has one Alarm Contact located on the top panel. For detailed
instructions on how to connect the Alarm Contact power wires to the two middle contacts of the
6-contact terminal block connector, see the Wiring the Alarm Contact section above. A typical
scenario would be to connect the Fault circuit to a warning light located in the control room. The
light can be set up to switch on when a fault is detected.
The Alarm Contact has two terminals that form a Fault circuit for connecting to an alarm system.
The two wires attached to the Fault contacts form an open circuit when (1) EDS has lost power
from one of the DC power inputs, or (2) one of the ports for which the corresponding PORT
ALARM DIP Switch is set to ON is not properly connected.
If neither of these two conditions occurs, the Fault circuit will be closed.
