Port A1 vs port A2

I have a quick question about ethernet ports: I have 2 machines that are communicating on our plant network via ethernet port A2. Given that the manual specifically says you can connect only port A1 to an enterprise-level network, how is this possible? Am I misunderstanding what an "enterprise-level" network is?

Details of one of the machines in question:

Controller: L320ERS2 Compact Guardlogix 5380 Safety
Port A1: device-level network
Port A2: enterprise-level network

The system is working with this setup, and also works if I switch everything so the ports are set up "correctly" (according to the manual).

If anyone is able to help me understand this, I would greatly appreciate it!

We only have a few of 5069 CompactLogix units at our site, all but one of them has been set up as per the manual, the other one is set up with the plant network on port A2 an it seems to be working fine (have not tried to change as there is a lot of IO on port A1 and the machine is running 24/7 at the moment), maybe RW TechSupport could be able to tell you why it is recommended to use port A1 on the plant network.

The Port A1 has the capability to communicate either on Enterprise-level network or Device-level network.

The Port A2 can only communicate on Device-level network.

Could it be a generic instruction that only pertains to certain revision levels?



Instead of breaking it down to which firmware revisions have to be this way, they just say do them all this way.

I came across this recently - only port A1 will let you set DNS servers or a domain. Both A1 and A2 will let you set IP address, subnet mask, and gateway.

The instances where it might be particularly important to use DNS and domain on a PLC are (in my experience, at least) very few. So for most purposes, it doesn't matter.

If you wish to enter and use the DNS/domain settings for any reason, you have to use port A2 for that.

ASF said:

I came across this recently - only port A1 will let you set DNS servers or a domain. Both A1 and A2 will let you set IP address, subnet mask, and gateway.

The instances where it might be particularly important to use DNS and domain on a PLC are (in my experience, at least) very few. So for most purposes, it doesn't matter.

If you wish to enter and use the DNS/domain settings for any reason, you have to use port A2 for that.

Click to expand...

Your last sentence contradict with 1st sentence.

A1 has the ability for DNS/Domain
A2 has the fields but they are greyed out.

Having the PLC able to cross domain boundaries would make IT security folks very unhappy. That's probably why you can't put that info (or at least different info) in A2. You can use a completely different subnet though which has been very convenient.

I have a telemetry system that is going end of life (NetCloud Perimeter) and its replacement requires DNS and Domain to function. That's going to be the only case where I will have to use Hostnames and DNS for more than convenience.

Thanks everyone for the quick replies.

It makes sense that it doesn't really matter except in a few specific circumstances. I guess Rockwell just didn't feel the need to explain that in the manual.

L33er said:

Your last sentence contradict with 1st sentence.

Click to expand...

Whoops, fat fingered the last sentence and missed the cutoff for editing the post. You get the gist!