The EM203 features four onboard status LEDs. The LEDs are strategically positioned on the edge of the module's board. Your product can have a small window or opening on its cover to make the LEDs of the EM203 visible from the outside (as shown on the drawing in the Ethernet Lines and Jack/Magnetics Data). When the EM203 is used in combination with the RJ203 module, the status LEDs are visible through a transparent portion of the RJ203's housing.
Onboard LEDs have the following function:
| • | Yellow Ethernet status LED is turned on when the EM203 links with the hub at 100Mb. The LED is off when the link is established at 10Mb. |
| • | Green Ethernet status LED is turned on when "live" Ethernet cable is plugged into the Module. The LED is temporarily switched off whenever an Ethernet packet is received. |
| • | Red and green status LEDs are under the control of EM203's firmware. |
The EM203 also has four LED control lines that allow you to add external LEDs in parallel with the onboard ones.