User guide

6 Product Overview ELH100-12/24TX
Figure 1-3 shows the Collision, Activity, Full/Half duplex, and Link LEDs
for the switch/media modules. These LEDs are positioned to the left of the
ports. In addition, the 10Base-T/100Base-TX module includes a 100M
LED to right of the ports to indicate speed (where On indicates that the
port is operating at 100 Mbps, and Off indicates 10 Mbps).
Figure 1-3. Port LEDs on the Switch/Media Modules
Table 1-3 defines the performance of the port LEDs on the optional modules.
Table 1-3. Port LEDs for Modules Defined
Name Function
Collision Flashing: Two or more devices attempted to transmit data at the same
time. (Normal situation under Ethernet CSMA/CD.)
Activity Flashing: Indicates the presence of transmit and/or receive activity.
Off: Indicates the absence of transmit or receive activity.
Full/Half On: Indicates the port is in full duplex mode.
Off: Indicates the port is in half duplex mode.
Link On: Indicates a valid connection (link) on the associated port.
Off: Indicates no link on the associated port.
100M* On: Indicates that the port is operating at 100 Mbps.
Off: Indicates that the port is operating at 10 Mbps.
* This LED only appears on the 10Base-T/100Base-TX module.
The Switch/Media modules do not support Span-
ning Tree, which is intended to prevent network
loops from forming. There is no loop detection. The
user is cautioned to understand and avoid configu-
rations that can create a loop.
Link
Activity
Full/Half
Collision