What can cause an Altivar 61/71 series drive with Ethernet/ Modbus TCP communication to obtain an IP address from the PLC but not be able to establish a connection?
What can cause an Altivar drive with Ethernet IP / Modbus TCP communication to obtain an IP address from the PLC but not be able to establish a connection?
Altivar 61/71/32 series drives.
All models and serial numbers where either Ethernet IP or Modbus TCP communication takes place.
One possible cause is if the IP address assigned to the drive has been previously used for other equipment, even another Altivar drive. The PLC expects a specific device to be connected to this IP address and if a different device is connected there, it can sometimes cause certain PLCs to not establish a connection with the drive.
If it is possible to power down the drive and PLC both, cycle power on the PLC first, then the drive, then re-scan your network from the PLC. If the PLC can not have power cycled on it for some reason, try changing the IP address of the drive to a previously unused address. You will also need to change the IP address in your PLC programming to reflect the new address.