The common Ethernet hub simply broadcasts each message it receives to every one of its ports. Each Ethernet device also has to wait for its turn to ‘talk’ to the hub, increasing the likelihood of message collisions; therefore, real-time operation is jeopardized and determinism is difficult. Alternatively, the SIXNET industrial Ethernet switch automatically determines and remembers where an Ethernet device is located and routes messages only through the appropriate port. Internal to the SIXNET Industrial switch is a memory for 1000 Ethernet MAC addresses so it remembers the routing for even the biggest industrial network. In addition, it contains over 1000 message buffers to store incoming messages until it is safe to transmit them over the appropriate network segment. This buffering not only avoids collisions, but it can further speed up the system by transmitting message packets over multiple network segments simultaneously.

		SIXNET Industrial Ethernet Switch
	Prevents message collisions and other problems Increases network bandwidth and speed Enables deterministic real-time performance

SIXNET Industrial Switches further enhance the performance of your network by performing automatic speed changes on the appropriate port. For example, EtherTRAK I/O modules communicate at 10 Mbits per second (which is more than adequate for the small lightly loaded messages needed to poll a small number of I/O points). These modules, when connected to an Industrial Ethernet Switch can be uplinked to a controller or computer at 100 Mbits per second. In effect, the computer can talk to ten times as many stations at the higher speed. The Industrial Switch routes the messages to multiple I/O stations at the reduced speed in parallel (at the same time).

By avoiding collisions and directing network traffic efficiently, the SIXNET Industrial Ethernet Switch promotes real-time performance in your deterministic industrial system. It is important to also point out that the software that is polling I/O must have deterministic performance as well.