Specifications

40 Input/Output Controller Replacement Instructions
Additional Information
Fast Ethernet MII Connection Equipment
The MII receptacle on the I/O controller is a 40-pin, D-shell type connector that is configurable for
100 megabits per second (Mbps). The MII receptacle supports IEEE 802.3u interfaces compliant
with the 100BASE-X and 100BASE-T standards. The MII connection requires an external
transceiver that permits connection to multimode fiber for 100BASE-FX or 100BASE-T4 physical
media. (See Figure 24.)
Caution Before connecting the transceiver to the MII receptacle on the I/O controller, check the
MII transceiver’s documentation (or with the transceiver’s manufacturer) to ensure the transceiver
responds to physical sublayer (PHY) address 0; otherwise, anomalies with the MII connection on
the I/O controller might occur. (PHY address 0 is defined in the section 22.2.4.4 “PHY Address” of
the IEEE 802.3u specification.) If present, we recommend using the transceiver’s “Isolation Mode”
setting if you are unable to determine if the transceiver responds to physical sublayer (PHY)
address 0.
Note To determine if an MII transceiver that is already connected to the MII receptacle on the I/O
controller responds to PHY address 0, ensure the I/O controller’s Fast Ethernet port is configured as
up and the MII receptacle is configured as the media type, then disconnect the transceiver from the
MII receptacle. If the Fast Ethernet port goes down, the transceiver responds to PHY address 0.
Figure 24 Fast Ethernet Port Connection
Depending on the type of media you use between the MII connection and your switch or hub, the
network side of your 100BASE-T transceiver should be appropriately equipped with ST-type
connectors (for optical fiber), BNC connectors, and so forth.
Figure 25 shows the pin orientation of the MII receptacle on the I/O controller.
The MII receptacle uses 2-56 screw-type locks, called jackscrews, to secure the cable or transceiver
to the receptacle. MII cables and transceivers have knurled thumbscrews that you fasten to the
jackscrews on the MII receptacle and tighten with your fingers. Use the jackscrews to secure your
MII cable to the MII receptacle.
MII
EN
RJ45
EN
RJ45
LINK
1O PWR
OK
RJ-45
CPU RESET
FAST ETHERNET INPUT/OUTPUT CONTROLLER
ENABLED
PCMCIA
EJECT
SLOT 0
SLOT 1
FE MII
H6853
Optional Fast Ethernet port
(MII receptacle and RJ-45 receptacle)
MII cable
To transceiver,
repeater, or DTE
To repeater
or DTE
RJ-45 cable
or