Open control technology: Connection of eight independent Ethernet networks to one PC

Beckhoff presents the CU2508 port multiplier for real-time Ethernet networks. In addition to EtherCAT and standard TCP/IP, PROFINET and EtherNet/IP are supported. In this way, several Ethernet protocols can be operated simultaneously on one controller. Unlike an Ethernet Switch, the CU2508 enables precisely timed transmission and reception of Ethernet frames by means of distributed clocks.

The CU2508 real-time Ethernet port multiplier has a gigabit uplink from the PC and eight independent 100 Mbit/s output channels. Each of the eight different ports can support any of the real-time Ethernet protocols. The PC transmits data at high speed to the port multiplier. A multiprotocol driver has been implemented in the TwinCAT automation software for the CU2508 Ethernet multiplier. This driver allows the use of different real-time Ethernet protocols on one device. The port multiplier analyses each packet and according to the frame prefix transmits the data to the appropriate 100BASE-TX port in a timecontrolled manner with µs precision. Received frames are also assigned a prefix including a time stamp and transmitted back to the PC on the gigabit port.

The CU2508 is primarily designed for large Industrial Ethernet networks or for the use of different Ethernet protocols on one controller. For extremely high demands, an EtherCAT installation can, for example, be distributed to up to eight separate networks in order to multiply the performance. The distributed clocks of all of the EtherCAT networks are synchronised. EtherCAT cable redundancy can also be realised using two ports of the CU2508.