In short
Replace 1785 PLC-5 processors and 1771 I/O with ControlLogix 1756 — conversion tools, chassis adapters, and timing.
PLC-5 → ControlLogix
Rockwell stopped manufacturing PLC-5 in 2017 (officially "discontinued"). Some 1771 I/O modules remain in repair-only status. Migration is no longer optional for long-term sites.
Option 1 — full ControlLogix rebuild
Best for facilities planning shutdowns. Use Logix Designer's PLC-5/SLC Conversion Tool to import RSLogix 5 source, then rework data types (PLC-5 integer files map to Logix tags).
Option 2 — keep 1771 I/O, replace processor
Use a 1756-DHRIO or third-party gateway to keep existing 1771 chassis alive while moving control to a 1756-L8 in a parallel chassis. Cuts downtime, lets you migrate I/O over scheduled outages.
What we stock
Ready-to-ship 1785-L20B / L40B / L80B processors, 1771-OB16/IB16 I/O, plus 1756-L8x targets for replacement.
Parts that fix this
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