The Siemens part number 6AV6676-6MB30-4AX0 refers to SIMATIC Modbus/TCP CP Red—a communication software package designed for redundant Modbus/TCP communication in S7-400H systems. It enables high-availability connections between SIMATIC controllers and third-party devices using the Modbus/TCP protocol.
Function: Supports redundant Modbus/TCP communication for S7-400H systems