his error can occur due to following causes. Check and correct the error and retry until connection issuccessful.1. The power for hub is not ON.2. The network cable connector is faulty or not connected correctly.3. Incorrect cable is used.4. IP address setting for the robot or the personal computer is not correct.Generally, there are LEDs on the hub or Ethernet connection interface devices. The signal status can bechecked by these LEDs. Use this information for troubleshooting when connection does not succeed.