ControlLogix ethernet comms to PLC5 rack

[dvcochran]

Hello,

I have a potential project and I am rusty in communication skills. The project will consist of a Control Logix platform with an existing program that will stay intact. It will connect via Ethernet connection to a rack of discrete PLC5 I/O. What will I need on each end and how to I address the discrete I/O via Ethernet? Is there a "cheat sheet" or similar to explain how to make the conversion? This is one of those projects that once it starts it cannot stop until complete. Any help is appreciated.

 

[JeffKiper]

The PLC5 doesn't have an Ethernet adapter. I commend replacement of the 5 chassis with a new *******Logix chassis. They make a changeover adapter that is supposed to make the change quick and painless. I haven't used the adapter plate yet so. I am going off salesman propaganda.

 

[Ken Roach]

Welcome to the Forum !

There is no EtherNet/IP adapter module for the 1771 platform. The only I/O adapters for the 1771 platform are for ControlNet and for the classic Allen-Bradley Universal Remote I/O protocol.

Is there a PLC-5E in that rack now ?

 

[dvcochran]

According to http://www.rockwellautomation.com/r...s-partners/technology-licensing/eipexp1_2.pdf, it is doable and quite common. What am I missing?

 

[dvcochran]

Allen Bradley has the 1785 PLC-5® EtherNet/IP™ Communication Interface Module which will communicate with any PLC5 with an Ethernet port. Are you saying this module will not communicate with Control Logix Ethernet port?

 

[dvcochran]

I will have to confirm but I do not think it has a 5-E processor.

 

[Mike_RH]

What is in the left slot of the 1771 IO rack now?
Is it a PLC5E? (As Ken asked).
You indicate that you want to scan discrete IO or do you wish to communicate to a PLC-5 in the rack?
A bit more detail would help. What hardware do you have, series and revision, and what exactly do you wish to do.

 

[dvcochran]

I want to scan the discrete I/O. The desire is for the existing PLC5 processor to go away and have everything integrated into the Control Logix. New equipment is being integrated with existing press.

 

[Bit_Bucket_07]

Allen Bradley has the 1785 PLC-5® EtherNet/IP™ Communication Interface Module which will communicate with any PLC5 with an Ethernet port. Are you saying this module will not communicate with Control Logix Ethernet port?

That module only connects to PLC-5 processors, doesn't it? It seems to me that dvcochran desires to address a remote 1771 I/O Chassis with a ControlLogix processor. Maybe I have misunderstood?

 

[Ken Roach]

The 1785-ENET is nicknamed the "Ethernet sidecar". It's been around since the early 1990s as an option module to add Ethernet connectivity to non-Ethernet PLC-5 controllers like the good old PLC-5/20, PLC-5/40, and PLC-5/80.

That module has a 50-pin connector that mates it up to the side of a PLC-5 controller. It cannot reside in a 1771 chassis by itself, and is not a 1771 I/O adapter.

The PLC-5E and 1785-ENET only have the ability to send and receive Explicit Messages over Ethernet. They have no cyclic I/O capability.

 

[Ken Roach]

I have done several PLC-5 conversions using the 1771-ASB (RIO) and using the 1771-ACNR15 (ControlNet).

If you are already running RIO (the old "blue hose") connection to a 1771-ASB adapter in that chassis, it makes sense to stick with RIO and use either the 1756-DHRIO or 1756-RIO scanner in the ControlLogix.

You mentioned that this is a project with a lot of momentum: "once it starts it cannot stop until complete".

Do you mean that this is a system that must have each phase performed with no process shutdowns ? That's not an easy task.

 

[dvcochran]

Mr. Kiper,
Are you saying there is a Logix chassis that will accept the 1771 I/O, which has or can have an Ethernet adapter to communicate with a Control Logix processor in a different rack?

 

[JeffKiper]

I think you need to understand how communications work. In the old days PLC5 era communication was handled by messaging. They master would ask the slave will respond. This only happens 1 time. They in the plc you have to tell it to ask for the data again. (Explicit messaging)

I the new ControlLogix era the slave and master setup a constant line of communication the master and slave talk all the time to each other. (implicit I/O)

 

[Ken Roach]

It's more of a wiring adapter.

The 1771 wiring arms and physical terminations remain, but the 1771-ASB, the 1771 chassis, the 1771 power supply and all the 1771 modules are removed.

A 1756 chassis, power supply, network, and I/O modules take their place, and a pre-wired set of adapters allow the 1771 wiring arms to connect to the 1756 I/O modules.

http://www.ab.com/en/epub/catalogs/12768/229240/229268/10941496/9657432/Introduction.html

 

[JeffKiper]

The manual you referred to has to keep the PLC5 in the chassis to Ethernet. If you want to eliminate the PLC5 you will need to replace the 5 with a communication adapter. I suggest replacing the entire PLC5 chasis (rack) with new 1756 I/O