Copyright 2017 Positron, Inc.
10
2.3.3 OEI for Type 1a or Type 1b
720920xxx TeleLite PSE Ethernet Card Located at the Substation OEI
(Note: Default DIP Switch Settings are shown in Figure 13)
A. The 720920xxx POE Ethernet card can only be locally powered by a source of -48Vdc. As such
there are no power jumpers to set on this card.
B.
The 720920xxx TeleLite PSE card is placed at the Substation’s OEI. If this location is likely to
be manned, the Master and Slave switches should be set so that the 720930xxx card is set as
Slave (See Type 1b, 720930xxx), and the companion 720920xxx card located at the OEI
(Optical Electrical Interface) is set as Master. Alarms will be reported to the attended 720920xxx
located at the OEI at the substation OEI. (Figure 14)
C. If this is a Type 1a or Type 1b Ethernet deployment as described in Section 1.2.1, the 2
nd
DIP
switch should be set to the left. (Figure 14)
D. If the Ethernet modem fed by the 720920xxx PSE TeleLite Ethernet cards is MDIX enabled
(3)
,
then the MDIX feature of the TeleLite Ethernet card should be disabled. If the associated
modems are NOT MDIX enabled, then this DIP switch should be enabled to remove any need
for crossover cables. With this feature enabled or disabled appropriately, there is never a need
with TeleLite Ethernet cards to provision the site with anything but a straight CAT 5 cable. In this
example the Ethernet Modem is MDIX enabled and the feature on the TeleLite Ethernet card is
disabled. (Figure 14)
E. If the 720920xxx card is to provide PSE to a terminating modem, the 4
th
DIP Switch is set to the
left. If the Ethernet modem at the OEI is locally powered by a source of -48Vdc, then the 4
th
DIP
switch is set to the right. (Figure 14)
In this example, the Ethernet modem at the OEI location is powered via the PSE output from the 4
ports on the faceplate of the 720920xxx TeleLite Ethernet card. (Figure 15)
3
defines a
medium dependent interface crossover
(MDI-X) interface.
Auto MDI-
X
ports on newer network interfaces detect if the connection would require a crossover, and automatically chooses
the MDI or MDI-X configuration to properly match the other end of the link.
Figure 13: Default DIP Switch Positions
Figure 14: Meeting conditions B, C, D, & E
720920SSC PSE
TeleLite Card (OEI)
Figure 15: 4 ports of
720920xxx
provide
PSE, if enable (DIP
Switch 4
)
