E42.03 fault in inovance IS580 drive indicates "the communication never gets online". This means the drive’s communication device (e.g., CAN, Modbus, Ethernet) never establishes an online connection with the master/controller. In other words, the drive attempts to connect but never successfully goes online.

• Check if A2-00 & A2-01 are setting correctly.
• Check if BUS wirings have loose connection or wrong connection.