PLC Ethernet or ENT2 Port for Machine Control

[PLCZ28]

An outside contracting firm designed a machine for our company. There are several devices
connected through Ethernet/IP. This includes a Panel View Plus unit , VFDs, Kinetix servo
controllers, Stratix 5400 switch and 5094-AEN2TR remote racks. As of now there is no other
external connections coming into the machine control system.
The vendor has the ENT2 module in Slot #0 and the PLC in Slot #1. The ENT2 module is
connected to the Stratix 5400 switch and the PLC port is only connected to access
port in the electrical cabinet front door.
In the past we have always used the PLC port to connect to the switch and machine network.
When used the ENT2 module was used to connect to outside networks. What is the
advantage of connecting the ENT2 module to the machine network instead of the PLC
port?

 

[TheWaterboy]

ENT2 is a more robust module for normal traffic. Also this arrangement allows you to use 2 subnets. one for the PLC and one for the rest of the system.

 

[PLCZ28]

Thank you for the explanation. But it seems by using the ENT2 module
that way instead of the PLC port invites more networking issues to procreate.

 

[TheWaterboy]

Thank you for the explanation. But it seems by using the ENT2 module
that way instead of the PLC port invites more networking issues to procreate.

What kind of issues are you worried about that this arrangement makes more possible?

 

[robertmee]

You didn't mention the PLC. If it's a new L8 series, there's really no advantage. The L8 on board port supports 1G, CIP motion, etc, so it's a viable machine network port. Typically, one or the other is reserved for process network connections, and the other for machine network. Me personally, I don't like to hang an HMI on my IO/motion control network. I prefer to segregate that traffic. All you need is a faulty Panelview sending bursts of traffic and affecting your critical motion and IO control.