AB migration

Hi, I work on and old plant, with some old SLC 05/04 PLC's controlling everything, we're on the middle of a reestructuration plan and one point is the update of the control and automation equipment.

In your experience migrating SLC's, what is the best approach? Migrating only the PLC and keep the old I/O ? Migrating everything to Compactlogix (rewiring) ? Contrologix?

Regards,

A customer that has been using PLCs (2s & 5s) and SLCs, all with remote racks, chose to just update the processors with ControlLogix and keep the remote racks. Best as I know, it has worked well. Little tricky with modules that use block transfers; it will require extra attention and/or replacement with something better interfaced to the newer processors.

Generally, it depends on how much remote I/O you have, what vintage, and what longevity you need...

SLC racks are still available, but not thought of as "current", so may be better to bite the bullet and upgrade to Compact Logix or Control Logix. If you speak nicely to your local Rockwell rep, they should have a "step forward" program, where if you choose to migrate to the new platform, they will give you a discount/refund when you return the old modules etc to them once the new system is up and running...

I have to look at my PLC5 systems, especially those with remote I/O racks, and the 1794-ASB module is no longer available to purchase. I need to migrate to new PLC processors and racks, but the Flex I/O racks can become Ethernet adapters.

For SLC conversions I use Control Logix as it's about the same size and I really have had bad luck with Compact Logix. I always try and keep the modules aligned right so the IO numbers can stay the same and rewiring is simpler also.