Ethernet - Ethernet.linkStatus()

Description

Tells you whether the link is active. LinkOFF could indicate the Ethernet cable is unplugged or defective. This feature is only available when using the W5200 and W5500 Ethernet controller chips.

Syntax

Ethernet.linkStatus()

Parameters

none

Returns

the link status (EthernetLinkStatus):

Unknown

LinkON

LinkOFF

Example

#include <SPI.h>
#include <Ethernet.h>

void setup() {
  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }
}

void loop () {
  if (Ethernet.linkStatus() == Unknown) {
    Serial.println("Link status unknown. Link status detection is only available with W5200 and W5500.");
  }
  else if (Ethernet.linkStatus() == LinkON) {
    Serial.println("Link status: On");
  }
  else if (Ethernet.linkStatus() == LinkOFF) {
    Serial.println("Link status: Off");
  }
}