EtherNet IP Integration

[kku 1]

Hi, I need some help integrating some future equipment using Ethernet IP. Currently I have a system that uses EIP. This system has two Keyence scanners, two Cognex cameras, and a Keyence network interface unit for three contact measurement probes. I checked the bandwidth usage using the Ethernet IP configuration tool and found a low number for network capacity usage (less than 5%). I attached a screen shot. Is this the correct number to look at? At what point will I run into issues with network traffic? These devices are connected using an unmanaged switch. At what point do I need a 'managed' switch? For some upcoming projects I plan on using more devices with EIP. These include robot controllers, screw driver controllers, Cognex cameras, barcode scanners, etc. I will probably get to 10 third party devices running EIP. These systems only use local networks. These will never be connected to the plant's IT network. Can I still get away with an unmanaged switch? Also when I am setting up connections, there is an option to designate if the connection is multi-cast or point-to-point. Should I always select point-to-point? I have one PLC so I don't think there is a need to 'multi'cast'. Thanks.

[RickyQ 1]

Since you are mostly doing p2p you should be fine, however, as you put more and more devices online i would multicast to improve overall performace. Once you go multicast I would recommend you get a managed switch that supports IGMP. I have seen unmngd switches get overwhelmed by multicast traffic. Point to point basically means that if your plc needs to send the same data to multiple devices it must send the data to each device one by one. In multicast mode the plc (or devices) only send the data once and listeners that need this data subscribe to the multicast group. Igmp will help the switch determine who the subscribers are and only forward the traffic to the appropriate port. Hope that helps...