Guide
SLC 5/03 vs 5/04 vs 5/05: Key Differences
Compare memory, communications and replacement requirements for Allen-Bradley SLC 500 processors.
Allen-Bradley SLC 500 and PLC-5 Discontinued Parts List (2026)
By TimControls Technical TeamPublished
Key takeaways
- Rockwell discontinued the SLC 500 processors on this list on 31 March 2024 (6 catalog numbers) and 31 December 2021 (the 1747-L541 and 1747-L551).
- The PLC-5 processors on this list went earlier, between 31 December 2012 and 31 July 2017.
- Rockwell classes the replacement for every processor on this list as an Engineering Replacement. Its SLC 500 migration path is CompactLogix 5380.
- Check the date on the exact catalog number: each has its own in Rockwell's record, and Rockwell can change it.
Every SLC 500 and PLC-5 processor we list, with its Rockwell status, the discontinued date from Rockwell’s Product Lifecycle Search and a link to it, checked on 15 October 2026.
On 31 March 2024 Rockwell Automation discontinued the last SLC 500 processors on this list, the 1747-L532, 1747-L533, 1747-L542, 1747-L543, 1747-L552 and 1747-L553. The 1747-L541 and 1747-L551 went on 31 December 2021.
The PLC-5 went first. Rockwell gives each PLC-5 processor its own date: on this list they run from 31 December 2012 (the 1785-L11B and 1785-L30B) to 31 July 2017 (the 1785-L80B and 1785-L80E).
Rockwell classes the replacement for every processor on this list as an Engineering Replacement. For the SLC 500 it publishes a migration path to CompactLogix 5380: a migration project, not a processor swap.
Every date here is from Rockwell’s Product Lifecycle Search for the exact catalog number. For how the three SLC processors differ, see SLC 5/03 vs 5/04 vs 5/05: Which Processor Do You Need?
Where the SLC 500 and PLC-5 stand
Rockwell’s Product Lifecycle Search gives each catalog number one of four statuses. This list shows the one each catalog number has, with its discontinued date.
| Rockwell status | What Rockwell says it means | Status on this list |
|---|---|---|
| Active | The most current offering in its product category | Active |
| Active Mature | Fully supported, but a newer product or family exists | Active |
| End of Life | Discontinued date announced; generally orderable until that date | Phased out |
| Discontinued | No longer manufactured or procured; repair or exchange services may be available | Discontinued |
- 17
- catalog numbers listed
- 17
- discontinued
- 31 Mar 2024
- latest Rockwell discontinued date
- 17
- classed as Engineering Replacement
Last checked against Rockwell’s Product Lifecycle Search on 15 October 2026.
Key dates
Every Rockwell discontinued date across the catalog numbers on this list, latest first.
| Date | Rockwell status | Catalog numbers |
|---|---|---|
| 31 March 2024 | Discontinued | 6: 1747-L532, 1747-L533, 1747-L542, 1747-L543, 1747-L552, 1747-L553 |
| 31 December 2021 | Discontinued | 2: 1747-L541, 1747-L551 |
| 31 July 2017 | Discontinued | 2: 1785-L80B, 1785-L80E |
| 31 December 2015 | Discontinued | 1: 1785-L60B |
| 31 December 2014 | Discontinued | 4: 1785-L20B, 1785-L20E, 1785-L40B, 1785-L40E |
| 31 December 2012 | Discontinued | 2: 1785-L11B, 1785-L30B |
Source: Rockwell’s Product Lifecycle Search for each catalog number, checked 15 October 2026.
SLC 500 and PLC-5 catalog numbers and their status
Every status and date below is from Rockwell’s Product Lifecycle Search for that catalog number. Rockwell can change a status, so the Source link in each row is the reference. The CSV adds Rockwell’s replacement category and, where it names one, its replacement.
SLC 5/03 processors (2)
SLC 5/04 processors (3)
SLC 5/05 processors (3)
Enhanced PLC-5 processors (6)
Ethernet PLC-5 processors (3)
How to use this list
A status in this list tells you what Rockwell says about a catalog number. It does not confirm that a unit is in stock, where it is or what condition it is in.
- Read the catalog number and series off the installed processor's label.
- Find it in the tables above and note its status and date.
- Open the Source link and check the Rockwell record has not changed since our last check.
- Discontinued and needed to keep running: rank it by what happens when it fails, and confirm supply for the ones that matter.
Before you ask for a quote
Two processors with the same catalog number can differ in series and firmware. Send us the catalog number, series and firmware revision from the label and we confirm the match before we quote.
Frequently asked questions
Are SLC 500 processors discontinued?
Yes, every one on this list. Rockwell's Product Lifecycle Search gives the discontinued date: 31 March 2024 for the 1747-L532, 1747-L533, 1747-L542, 1747-L543, 1747-L552 and 1747-L553; 31 December 2021 for the 1747-L541 and 1747-L551.
When was the PLC-5 discontinued?
Rockwell gives each PLC-5 processor its own date. On this list: 31 December 2012 for the 1785-L11B and 1785-L30B; 31 December 2014 for the 1785-L20B, 1785-L20E, 1785-L40B and 1785-L40E; 31 December 2015 for the 1785-L60B; 31 July 2017 for the 1785-L80B and 1785-L80E.
What does Rockwell name as the replacement?
Rockwell's record puts the replacement for every processor on this list in its Engineering Replacement category; none is listed as a direct replacement. For the SLC 500, Rockwell publishes a migration path to CompactLogix 5380. Either way it is a migration project, not a processor swap.
How often is this list checked?
Each catalog number is checked against Rockwell's Product Lifecycle Search. The date of the last check is on this page and in every row of the CSV.
Can I use the CSV?
Yes. It has the same columns as the list, plus Rockwell's replacement category and replacement, and the Rockwell source for each catalog number. Check that source before you rely on a status.
Sources. Rockwell Automation’s Product Lifecycle Search for each catalog number, checked 15 October 2026. Statuses can change; the Rockwell record is the reference. Rockwell’s SLC 500 migration page: SLC 500 migration.