GE L90 Instruction Manual page 65

3 HARDWARE
c) 10BASE-F FIBER OPTIC PORT
ENSURE 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.
CAUTION
OBSERVING ANY FIBER TRANSMITTER OUTPUT MAY CAUSE INJURY TO THE EYE.
CAUTION
The fiber optic communication ports allow for fast and efficient communications between relays at 10 Mbps. Optical fiber
may be connected to the relay supporting a wavelength of 820 nanometers in multimode. Optical fiber is only available for
CPU types 9G and 9H. The 9H CPU has a 10BaseF transmitter and receiver for optical fiber communications and a second
pair of identical optical fiber transmitter and receiver for redundancy.
The optical fiber sizes supported include 50/125 µm, 62.5/125 µm and 100/140 µm. The fiber optic port is designed such
that the response times will not vary for any core that is 100 µm or less in diameter. For optical power budgeting, splices are
required every 1 km for the transmitter/receiver pair (the ST type connector contributes for a connector loss of 0.2 dB).
When splicing optical fibers, the diameter and numerical aperture of each fiber must be the same. In order to engage or dis-
engage the ST type connector, only a quarter turn of the coupling is required.
GE Multilin
Figure 3–19: RS485 SERIAL CONNECTION
L90 Line Differential Relay
3.2 WIRING
3
3-19