Getting info via an Ethernet from PLC to PLC. 1

[bdn2004]

An equipment manufacturer is going to provide a PLC to operate their equipment. It's about a hundred I/O points or so. We are going to have a remote screen made up like we want on our system that we show the points they have recommended we watch at all times. They said they will provide this via a blue hose connection. Which I assume means an Ethernet connection.

The manufacturer's PLC is an ABB 800PEC and our PLC is Allen Bradley Controllogix. What information does a programmer need in order to create our custom screen and know he is addressing the right point? Is there a common name for this document? I'm trying to write a scope to get this work done. And I want to request from ABB this info.

 

[danw2]

It is probably not ethernet. If the original statement had meant ethernet as a transport layer, I suspect the term 'ethernet' would have been used, but it wasn't.

Belden Wire has a trademarked line of cable known as 'Blue Hose'

http://www.belden.com/pdfs/prodbull/NP158.pdf

Allen Bradley/Rockwell popularized the term 'blue hose' for use with their proprietary Data Highway Plus (DH+) protocol some decades ago. I'm not an A-B guy so for all I know DH+ might have gone to ODVA for gate/tollkeeping.

I think of blue hose as cable/wire. I've used blue hose for Modbus RTU. The cable/wire does not necessarily define the protocol (there might be a convention in the ABB world?)

I think you need to inquire as to exactly which protocol runs over Blue Hose.

 

[bdn2004]

Thanks Dan for your answer. I can use it.

But my question is more of what type info do I need to request of ABB so we can make up our own screens. How does whatever protocol know what I/O is what and what if its a calculated value via their plc? Doesn't there have to be some type of mapping of the points?

 

[djs]

First you need the type of interface on the ABB PLC: ethernet, RS-485, RS-232-C etc. This determines the physical link and the wiring necessary. You will need to have the exact same interface at the other end. Cannot connect ethernet to RS-232-C for example.

Second you will need to know the protocol used. This is the "language" used over the physical link. For example ethernet can talk Ethernet/IP, Modbus TCP/IP etc. You will then need to have the software/firmware at the other end to handle the protocol.

Finally you will to know the data point addresses. These can be a number, name or a combination of both.