Installation
8
However, you may want to use one of the 10BASE-T ports to link one hub to
another (you can also connect hub to hub via the network port). This type of
connection requires the signal to “crossover” so that the TX pin at one end
connects to the RX pin at the other end. You can accomplish this in either of
two ways:
❑
You can use a special crossover cable, available commercially at most
electronic outlets.
❑
You can use a built-in method for internally crossing the signal over,
before it is transmitted through the cable.
ATI has incorporated the latter feature into the AT-30xxTR models. The
Medium Dependent Interface (MDI/MDI-X) switch at the far left of the
AT-30xxTR front panel converts RJ45 Port #1 from a normal network
connector into an internally crossed-over port for hub-to-hub connection:
❑
The default setting for the switch is MDI-X (standard RJ45 port) (see
Figure 7).
❑
If you want to use Port #1 to connect two hubs, you must set the
switch on one, and only one, of the hubs to the MDI position.
By using the MDI/MDI-X switch, you can connect two hubs via standard
straight-through cable. The switch affects Port #1 only; you can continue to
use all the other 10BASE-T ports for network connections via straight-
through cable, no matter which way you set the MDI/MDI-X switch.
If you connect a straight-through cable (or any cable for that matter) between
two hubs (or any two nodes), and the network LEDs do not indicate a link
condition, change the MDI/MDI-X switch to the other setting. The repeater
will not be damaged if the MDI switch is in the wrong position.
Figure 7: MDI/MDI-X Switch
1
2
3
4
5
6
7
8
9
10
11
12
X
X
X
X
X
X
X
X
X
X
X
ACTIVITY
COLLISION
POWER
1
2
3
4
5
6
7
8
9
10 11 12
1
2
3
4
5
6
7
8
9
10 11 12
TERMINATOR
OFF
ON
PORT OK
RECEIVING
PORT OK
RECEIVING
PORT OK
RECEIVING
POWER
10BASE-T NETWORK PORTS
10BASE-T PORT ACTIVITY
STATUS
AUI
BNC
1
2
3
6
1
2
3
6
1
2
3
6
1
2
3
6
MDI
MDI-X
IEEE 802.3
/ETHERNET
1
0BASE-
T
MUL
TIPORT REPEA
TER
1
1
2
3
6
1
2
3
6
1
2
3
6
1
2
3
6
MDI
MDI-X
