MicroLogix & PLC5 Networking Help

We have several dozen PLC5's, some with ethernet cpu's and some with DH+. We have upgraded as convenient the DH+ to ethernet with bridges so they are all on our "Plant PLC" network. We have all the computers on the "Plant Admin" network.

So we are being directed by corp. to install a new piece of equipment and somehow integrate it into the Plant PLC network.

MicroLogix 1100 <--- Ethernet/IP ---> Metler Toledo Scale <--- Admin Network ---> Logging PC

The MicroLogix only has one Ethernet/IP port so we are trying to figure out how to put it on the Plant PLC network so the PLC5's can control flow in/out of the new equipment.

Option 1) MicroLogix1100 <--- Ethernet/IP --> Stratix 5700 Managed Ethernet Switch <-- Plant PLC Network. Then we could plug the Scale controller into the AB Switch and everybody is talking directly.

Option 2) Plant PLC Network --> AB 1761-NET-ENI <---> MicroLogix rs232 port <--- Ethernet/IP ---> Metler Toledo Scale <--- Admin Network ---> Logging PC


I am almost tempted to purchase both options just to guarantee the commission date but wanted to ask and see if anyone has used a switch in this kind of situation.

Option 1 I think is the best Idea.

I don’t see any reason why you would want to bridge Ethernet to the DF1 port. However keep in mind that the MicroLogix 1100 is limited to 16 connections and one device can use two connections. So if you’re going to have multiple devices connecting to the MicroLogix 1100 then you need to figure out how many connections there will be.

Adding onto Firejo 's post

If a NetENI is used it is more limited with connections I think its limited to 6

Have you considered adding a HMI computer that can connect to the ML, read a word of bits from the ML & send it out across the other ports?

AdvancedHMI can read from one PLC a word and send it out to other PLC's on different ports through Data Subscribers.

So the "Scale System" consists of a MicroLogix 1100 and Scale controller (Mettler Toledo IND780) in one piece of equipment. We are replacing an existing scale system that is currently controlled from the PLC5 and the scale readings are taken from a basic interface off the old scale display. The basic interface is getting flakey so this "all in one" scale system was purchased and given to use to "make work". Each MicroLogix has an extra input and output expansion module so they are fully loaded.

We have been upgrading the PLC5's by connecting a few racks together with new Compactlogix and switches as their new brains and running the PLC5 racks as remote IO. I just assumed the ethernet to the PLC5's and the "Plant PLC" network where Ethernet/IP.

If we can put all three devices on the Plant PLC network then we can treat the MicroLogix as remote IO and all the field wiring can stay on the PLC5. We can then just pass the scale data around and the micrologix can just sit there mostly ignored.

We do plan on upgrading the whole PLC5 rack in this location in the next 12-18 months but we need new scales right now.

Just for topic closure 3 years later we ended up putting the PLC5 on RIO and putting in a ControlLogix to bridge all the communications. It's still a bit of a cluster but it works...

uminded said:

Just for topic closure 3 years later we ended up putting the PLC5 on RIO and putting in a ControlLogix to bridge all the communications. It's still a bit of a cluster but it works...

Click to expand...

Better late than never, thanks for coming back and updating the thread! :site: