Migration from Bailey DCS to PLC

[econ]

I am conducting a business case that investigates the value of upgrading the 15 year old Bailey Network 90 (N90) controller of a Water Purification Plant (WPP) to a PLC/SCADA system.
I am fairly new to DCS/SCADA systems, but I have good experience with PLCs. I have had trouble getting reliable, unbiased information from all parties (suppliers and employees). I’d like to know how outdated the N90 (now known as INFI90 Open) is. I know that Bailey has been taken over by ABB and it is still supported with hardware. But I don’t know how much of the original underlying architecture (comms between modules, addressing system, etc, which I imagine must be slow and inefficient by today standards) has been preserved to make it backward compatible, and to what extent this will limit the lifetime of the product. Do ABB have plans to phase out this line in the near future? I’ll appreciate any contributions.

 

[xnuke]

I've recently worked on a similar project to replace an obsolete Rosemount Manager 16 HVAC control system with GE Fanuc PLCs. I can't comment on the choice to do so or the selection of PLC brand because those decisions were made prior to my employment. I can say that other DDCs were compared against the PLCs and the PLCs were cost-justified as well as a more flexible platform for programming.

One thing to watch out for - if your DCS is retransmitting a lot of control data over the communications network, make sure you put in a new communication system prior to starting to move points from the DCS to the PLC. I had one single input point left to transfer, and when I looked deeper into its function, I realized that it was retransmitted from the marshalling panel across the comm network to another Rosemount panel in another building that performed the control function. Fortunately, I was able to set up an Ethernet link to another PLC with a single output card in a third Rosemount panel, feed it into the Rosemount using an isolator, then retransmit it from there. (Since I plan to replace all the Rosemount equipment eventually, putting in another PLC was okay, just earlier than expected.) I have since put in a parallel Ethernet network, and as I replace stuff in the future, retransmission of point or control data will no longer be a problem.

xnuke

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[OllieC]

We recently replaced the OIS units with iFix SCADA running on W2k, as the console boards were getting more and more expensive and harder to find. This applies to the DCS too, we would consider replacing with PLCs but this is too big a project at the moment. Would be interested to hear if you do decide to replace.

regards
Oliver

 

[econ]

The OIS have already been replaced with Conductor NT.
So far it appears that the hardware is still well supported.
I was told Harmony Rack systems are still ABB's mainstream DCS product and are 100% compatible with Network 90 systems. If this is the case, why is your experience different?
I will let you know of the outcome.

econ

 

[10orchard]

Have you considered other options such as a plu in upgrade to a new system - eg another DCS such as IA Series?
this requires no rewiring..... and replaces all of the legacy system.....

 

[jsummerfield]

Regardless of the system being replaced, you are in for a major programming change when you change the system I/O. This justifies a new bid for all comers that meet your requirements. Define any interfaces that exist or are planned. Define the interaction such as monitor only vs bidirectional control data interaction.

Prepare the specification for an apples-apples basis. Specify all requirements such as hardware, assembly, programming, factory testing, field installation, site acceptance testing, startup support, training, etc. Identify the source of existing information such as the existing DCS database, P&IDs, schedule, etc. Many suppliers will bid on time and materails only for services outside the factory.

For a lump sum turnkey project, plan on new charges for any minor change. Define your requirements up front, once. Obtain the training to fix all minor changes in-house.

Expect the supplier to lie to you, especially about schedule. Consider the availability of trained support in your plant or area outside the supplier organization.

Good luck.




John