GE B30 UR Series Instruction Manual page 79

3 HARDWARE
Lightning strikes and ground surge currents can cause large momentary voltage differences between remote ends of the
communication link. For this reason, surge protection devices are internally provided at both communication ports. An iso-
lated power supply with an optocoupled data interface also acts to reduce noise coupling. To ensure maximum reliability, all
equipment should have similar transient protection devices installed.
Terminate both ends of the RS485 circuit with an impedance as shown below.
c) 100BASE-FX FIBER OPTIC PORTS
Ensure that the dust covers are installed when the fiber is not in use. Dirty or scratched connectors can lead to high
losses on a fiber link.
NOTE
The fiber optic communication ports allow for fast and efficient communications between relays at 100 Mbps. Optical fiber
can be connected to the relay supporting a wavelength of 1310 nm in multi-mode.
GE Multilin
Figure 3–24: RS485 SERIAL CONNECTION
B30 Bus Differential System
3.2 WIRING
3
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