b) 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.
OBSERVING ANY FIBER TRANSMITTER OUTPUT MAY CAUSE INJURY TO THE EYE.
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 9C and 9D. The 9D 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.
(DC SHIFT OR
SIGNAL CAN BE USED)
IRIG-B is a standard time code format that allows stamping of events to be synchronized among connected devices within
1 millisecond. The IRIG time code formats are serial, width-modulated codes which can be either DC level shifted or ampli-
tude modulated (AM). Third party equipment is available for generating the IRIG-B signal; this equipment may use a GPS
satellite system to obtain the time reference so that devices at different geographic locations can also be synchronized.
GE Power Management
GPS SATELLITE SYSTEM
RG58/59 COAXIAL CABLE
Figure 3–21: IRIG-B CONNECTION
L90 Line Differential Relay
TO OTHER DEVICES