11. Connection to other devices11.3 Setting up a NET11.3 Setting up a NETNET - a groupA NET is a group that is made up of up to eight stations and that uses a special protocolfor the device series in order to allow for communications via Ethernet connections.The name "NET" refers to Ethernet/UDP-based communications between the easyE4devices. It was designed specifically with the needs of straightforward transfersbetween easyE4 devices in mind. Within a NET, every device has read access to theNET operands of any other device in its group. In addition to this, data can be trans-ferred both cyclically and acyclically.Please note that nodes from different groups cannot communicate directly with eachother.Between groupsIf, however, you want devices to be able to communicate across groups, you will needto use a coordinator device that controls the corresponding communication with Mod-bus TCP.A total of ten NET groups (groups 1 through 10) can be run on a single Ethernet networkat one time.Ethernet network↑ ↑ ↑ ↑ ↑ ↑ ↑Module Module Module Stations… Module Module ModuleNET-ID 1 NET-ID… NET-ID 8 NET-ID… NET-ID 1 NET-ID… NET-ID 8NET group 1 NET group… NET group 10NET uses UDP protocols that send unconfirmed broadcast frames; accordingly, thedevices in the NET group must be located on the same subnet. Connections through arouter are not allowed, as broadcast frames will normally be unable to pass through arouter.Figure 253: NET diagramAll easyE4 base devices feature an Ethernet port that can be simultaneously used for allcommunications, e.g., web server, Modbus TCP, e-mail, and programming the easyE4.easyE4 11/18 MN050009 EN www.eaton.com 537
