A Redundant Comport consists of primary and backup communications Ports on the SCADA node. This enables a redundant communications path to the Device. If communications cannot be established through this Comport, Advantech WebAccess/SCADA will try a second Comport, specified as the Backup Port. You configure the backup Port number in Advantech WebAccess/SCADA, but without any devices on it. Usually the device must have two comports also. Not all Device Types support a backup Port.
The Backup Port is usually configured as the same type. However, some Device Types allow the backup port to be another physical type; for example, Modicon Device can use a TCP/IP (network) port as a backup port to a Serial Port.