The EM203A 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 EM203A visible from the outside. When the EM203A is used in combination with the RJ203A module, the status LEDs are visible through a transparent portion of the RJ203A's housing.
Onboard LEDs have the following function:
| • | Yellow Ethernet status LED is turned on when the EM203A 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 EM203A's firmware. |
The EM203A also has four LED control lines that allow you to add external LEDs in parallel with the onboard ones.