What can an LED be used as in a communication setup?

In a communication setup, an LED can function effectively as a signal source. When an LED is powered and emits light, it can indicate on/off states or represent digital signals. In data communication, this property is utilized in various applications, such as visual signaling where an LED lights up to represent a '1' or goes off for a '0.' This characteristic can be particularly useful in simple signaling applications, such as indicating when data is being transmitted or received.

The use of an LED as a signal source takes advantage of its ability to show the presence of a signal visually, making it easier to diagnose or monitor communication lines. This versatility is why LEDs are often found in communication equipment as indicators or in optical transmission systems where light signals represent data.