PLC-5 to ControlLogix upgrade

[plcgeek 0]

I have been tasked with engineering an upgrade situation. I have a PLC-5/40 that needs to be updated to ControlLogix. This PLC-5/40 has a ton of discrete I/O cards and has a Remote I/O rack connected to it with another bunch of discrete I/O cards. One of my fellow engineers insists that he has seen PLC-5 racks (complete with discrete I/O cards) converted so that the PLC-5 CPU was removed, replaced with some type of bridge card and this bridge cards then connected to a ControlLogix PLC that ran the old PLC-5 I/O on the rack. Anyone have any idea what he might be referring to?

[Mickey 71]

See links below 1756-DHRIO gateway. http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um514_-en-p.pdf http://literature.rockwellautomation.com/idc/groups/literature/documents/in/1756-in003_-en-p.pdf

[Ken Roach 194]

I do it all the time. You use a 1756-DHRIO or 1756-RIO scanner card in the ControlLogix, and replace the PLC-5 with the same kind of Remote I/O Adapter module that's in the other remote rack (1771-ASB). The principal drawbacks are analog module capacity (not a problem in your case) and I/O speed for the backplane-resident modules. You could use ControlNet if you really needed super-fast control over the previous "local" I/O rack.

[JRoss 84]

AB now also has an upgrade path from PLC5 to ControlLogix that completely replaces the backplane, cards, etc. All that remains is the swing-arm terminal blocks. It's essentially a fancy set of terminal breakouts for the ControlLogix cards that accepts the PLC5 swing-arms.

[BobLfoot 302]

You've been given several good ideas. There is also the 1771-CNB card which lets Cotnrol net connect your PLC5 racks to a COntrollogix CPU. And I think there might even be a 1771-ENB. The chief advantage of going to CLGX with PLC5 I/o and then moving the I/O to CLGX type is you can test the CLGX program on weekends and put the PLC5's back in for weekly production until you get the CLGX bugged out.

[Guest]

suggestion: tell us WHY the system needs to be updated ... in some cases, the best answers to your questions will depend on exactly what advantages you're trying to gain from using the ControlLogix controller ...

[plcgeek 0]

I appreciate the helpful input. Gonna have to consider my options. Thanks! Great video on the upgrade kit from PLC-5 to ControlLogix: http://mms.rockwellautomation.com/idc/groups/multi_media/documents/multimedia/1771to1756.wmv Edited 14 Mar 2011 by plcgeek

[TConnolly 13]

Bob, I wouldn't recommend using the 1771 control net scanner card at this point. It is marked as silver series and is slated for discontinuance in 2012. See http://www.ab.com/silver/io/1771.html My guess is there isn't enough demand. The DHRIO upgrade path is the one that I've seen most often and none of those components have been designated as silver series. Also see this thread for a similar discussion: http://www.plctalk.net/qanda/showthread.php?t=61937