Obsolete Allen-Bradley PLC-5 Parts Sourcing

PLC-5 defined American factory automation from 1985 to 2000 — and thousands of racks still run. We source 1785 CPUs, 1771 I/O and network adapters worldwide.

The Allen-Bradley PLC-5 (1785 chassis family) was the backbone of North American manufacturing from the mid-1980s until the ControlLogix transition. Rockwell no longer supports it, 1784-KTX and 1784-PCIC programming cards are increasingly scarce, and a failed CPU on a PLC-5 line means a gray-market hunt with 4-8 week lead times.

TGK Parts sources obsolete PLC-5 parts through a global surplus network. Send the catalogue number (e.g. 1785-L40E, 1771-IFE) or a nameplate photo — we reply within 12 hours with availability, condition and price. Every unit is bench-tested before shipping with a 12-month warranty.

PLC-5 families and modules we source

SeriesDiscontinued modelsCurrent replacement
PLC-5 CPUs (classic)1785-L11B/L20B/L30B/L40B/L60B/L80B, LxxE Ethernet variantsControlLogix 1756-L8x retrofit
PLC-5 I/O (1771 series)1771-IFE analog input, 1771-OFE analog output, 1771-IBD/OVD/OBD digital, 1771-OWEDirect surplus sourcing
PLC-5 chassis & power1785-C1E/1ET backplanes, 1771-P4R/P5/P7 power suppliesDirect surplus sourcing
PLC-5 networking1785-ENET Ethernet adapters, 1785-KA5/KT/KT2 comms modulesDirect surplus sourcing
Programming hardware1784-KTX, 1784-PCIC cards, 1784-T45 terminals, RSLogix 5 licensesSourced as surplus
Adjacent legacy ABSLC 500 (5/01-5/04), PLC-2/3, early ControlLogix revisionsSee our SLC 500 pages

Our sourcing process (quote within 12 hours)

  1. Send the PLC-5 catalogue number or nameplate photo — include the chassis size (1/4, 1/2, 3/4, full rack) and any Ethernet adapter model.
  2. We query the global surplus network — North American decommissioning stock and integrator inventories are the richest sources for 1785 hardware.
  3. You receive a quote within 12 hours with condition stated clearly: tested surplus or refurbished, with photos.
  4. Bench testing before shipping: power-up, program load and run, I/O forcing, Ethernet comms where applicable — 12-month warranty on every unit.

Frequently asked questions

Can you source a PLC-5 CPU like the 1785-L40E?

Yes — 1785 CPUs are a core sourcing line. Send the exact catalogue number and chassis type; we reply within 12 hours with availability and price.

Is 1771-IFE still available?

It is one of the most-requested PLC-5 modules on the surplus market. We source it regularly as tested surplus — send your I/O count for a quote.

Can you pre-load my PLC-5 program?

Yes — send your RSLogix 5 backup and we load, verify and run the CPU on a test rack before shipping.

What about the 1784-KTX programming card?

Increasingly scarce as PCI slots disappear. We source them as surplus and also supply USB-to-DH+ alternatives for maintenance access.

Should I repair, source a used PLC-5, or migrate to ControlLogix?

We quote the used-CPU path first (usually the fastest), and flag the migration option when a rack fails repeatedly. Our engineering partners handle the 1785-to-1756 conversion when you are ready.

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