PLC3-10 upgrade options

[sd00 1]

Hi, we have an obsolecence issue with PLC3-10 & are looking at upgrade options. Idealy, I would swap out the PLC3-10 processors for modern AB processors & (initially) reuse all of the existing RIO. The logic behind this thinking is that the thousands of IO points can continue to function and be slowly migrated to modern IO over a loger period of time - this would minimise the hardware changes duing the relatively short shutdown period & allow us to utelise the modern processors with minimal risk. Q: Do the newer processors (e.g. 5000 series) have the ability to connect to and use IO over RIO (i.e. is there a RIO scanner for the newer AB PLCs)? Q: Is there a 3rd party RIO scanner that would allow another type of PLC to run the facility (the departments prefered PLC manufacturer is Mitsi) Any other advise would be greatly appreciated. Regards, Steve.

[Ken Roach 194]

Yes and yes. PLC-2/3/5 migrations are a substantial part of my business. ControlLogix has two RIO scanners; the classic 1756-DHRIO which has two configurable ports for DH+ and RIO interfaces, and the newer 1756-RIO which handles all the scanning and block transfers onboard the module. The 1756-DHRIO is simpler to use but the ControlLogix has a limited messaging capacity on RIO and DH+, so if you have more than 16 analog modules in your RIO system you run out of BTR/BTW "Cached Connections" and must implement a buffer conservation logic strategy. The 1756-RIO uses an offline configuration tool and is more complicated to use, and has two major benefits; it processes all Block Transfers onboard, so it can handle even the massive RIO networks that some PLC-3 systems used, and it has a "Shadow Mode" feature. In "Shadow Mode" the module can be attached to an existing RIO scanner and will listen to the input, output and block transfer data on the RIO network and place it into the ControlLogix tag database. This allows us to write and test the converted ControlLogix program and perform extensive runtime testing, comparing the output results of our new program with the output results of the existing processor, to verify that the translation has been successful and accurate. The switchover between PLC-2/3/5 can then be accomplished very quickly by disconnecting the existing scanner and loading the "Scanner" firmware into the 1756-RIO. The troubleshooting and translation work can be done over the span of weeks or months, rather than during the switchover between systems. There are a couple of third party providers to know about when doing PLC-3 and RIO conversions. A company out of New York called Javlyn Inc. specializes in PLC-3 conversions. They have a lot more PLC-3 experience than I do, as the Three was popular well before my time with Rockwell. http://www.javlyn.com/plcconversion.htm Quest Technical Solutions (http://qtsusa.com/ab.html) makes a standalone equivalent to the 1756-RIO that connects with ControlLogix over EtherNet/IP I/O messaging instead of over the backplane. I am unfamiliar with Mitsubishi's ability to interface with EtherNet/IP. I wouldn't personally want to get in the middle of a three-vendor control solution but your facility's preferences and decisions may be different.

[sd00 1]

Thank you very much Ken - this information is very good news. "PLC-2/3/5 migrations are a substantial part of my business" - Are you in the UK? Do you do software conversions PLC3 --> ControlLogix? Do you do full conversion & installation? Cheers, Steve.

[Ken Roach 194]

I'm a Rockwell Automation field service engineer in the Pacific Northwest of the US. Most of my work is consulting and troubleshooting while my customers are doing their own installations and migrations. Rockwell has a small specialized group inside our Field Service business who run our automated conversion software, then those of us in the field "clean up" and complete the conversions, including aspects like the 1756-RIO shadow / scanner and the external interfaces to HMIs and DCS systems. I'm not familiar with the staffing and structure of Rockwell's operations in the UK.

[ratcliffe_ic 2]

Hi, I would be able to look at your PLC3 and provide a cost for conversion and installation. Drop me an email.

[BobLfoot 301]

I am neither an RA Employee or a System Integrator anymore but now work maintenance for an End User and have been through several PLC 5 to Control Logix Conversions. Let me share some of my opinions and insights if I may. The path you are considering is what I call CPU Upgrade first ; I/O Upgrade second and has significant cost and uptime advantages. The conversions I went thru where on equipment running 24 x 5 and was down on the weekends. We would remove the PLC 5 CPUs and palce them in spare hot holding racks to keep thier programs fresh rather than relying on batteries. We would then insert our Network Comm Modules {we used a mix of Controlnet and Remote I/O at first but have no migrated mostly to Ethernet I/O Adapter in our 1771 racks.} We could perform I/O checkout and dry runs on the weekends returning to PLC 5 Control for Production Startup on Mondays. After anywhere between 3 and 6 weekends we'd reach a go live day and not switch back on a Monday Startup. If something catastrophic happened in the first month we coyuld always fall back to the PLC 5's. it meant a longer install time frame for the System integrator but more productivity for us. Definietly use the resources of RA and an integrator with experience in this conversions. The gotchas are few but they can be major. Be sure your maintenance staff get RSlogix 5000 Training from a reputable source. Control Logix PLCs are not PLC 5's or in your case 3's and they behave differently under failure / adverse conditions. Not wrong or badly, just different.