Description
Note: Many products are not yet listed. Please contact us for more product information. Our supply channels are constantly expanding, and we currently have 20 stable shared supply channels. Please confirm the model, product, price, and all other necessary information with customer service before placing an order. We offer new, refurbished, and used products, and prices are adjusted according to the year of the item you require.
3. Key Technical Specifications
| Parameter | Value |
|---|---|
| Catalog Number | 1747-L541 |
| Processor Type | SLC 5/04 |
| User Memory | 16K words |
| Max Discrete I/O | 4096 inputs + 4096 outputs |
| Max Analog I/O | 480 points |
| Communication Ports | DH+ (Data Highway Plus) and RS-232 |
| Typical Program Scan Time | 0.9 ms per K word |
| Typical I/O Scan Time | 0.225 ms |
| Max Local Chassis | 3 chassis / 30 slots |
| Backplane Current | 1 A @ 5 V DC |
| Programming Software | RSLogix 500 |
| Keyswitch | RUN / REM / PROG |
4. Product Introduction (Anti-Template)
The 1747-L541 is the 16K-memory version of the Allen-Bradley SLC 5/04 processor. It installs in slot 0 of any SLC 500 modular chassis and serves as the central controller for the system.
It offers significantly faster communication than the earlier SLC 5/03 through its built-in DH+ port, while retaining a standard RS-232 port for programming, DF1, DH-485, Modbus RTU master, or ASCII devices. The processor supports up to 4096 discrete inputs and outputs plus 480 analog points across a maximum of three local chassis. Program execution is typically 0.9 ms per thousand words. Although Rockwell discontinued the SLC 500 family, the 1747-L541 remains widely used in existing installations and is still actively supported through surplus and repair channels.
1747-L541
1747-L541
1747-L541
1747-L541
5. QC, Procurement & Logistics SOP
- Inbound Verification – Confirm full catalog number (1747-L541), series/revision letter, keyswitch operation, and LED condition. Photograph all labels.
- Live Rig Testing – Install in a compatible SLC 500 chassis, apply power, verify keyswitch modes, battery status, DH+ and RS-232 communication, and basic program load/run capability.
- QA & Anti-Static Packaging – After functional inspection, protect the backplane connector and communication ports, clean the module, and seal in anti-static packaging with desiccant.
- Global Logistics & Export Compliance – Classify under the correct HS code for PLC processor modules. Packaging must protect against electrostatic discharge and mechanical shock; export documentation is prepared to minimize customs delays.
6. Technical Pitfalls & Integration Warnings
Memory Module Confusion – Optional 1747-M memory modules provide program backup only; they do not expand the processor’s working 16K user memory.
Battery Maintenance – The lithium battery (1747-BA) maintains RAM during power loss. A low or failed battery will cause program loss on power cycle.
Chassis and Power Supply – Ensure the chassis power supply can support the 1 A @ 5 V draw of the processor plus all I/O modules.
Firmware and Software – Use a compatible version of RSLogix 500. Mixing very old and newer OS series can cause compatibility issues.
7. Frequently Asked Questions (FAQ)
What is the realistic global lead time for a verified 1747-L541?
Surplus and refurbished units are commonly available. Typical lead time after verification is 1–7 business days plus standard shipping.
What is the memory size of the 1747-L541?
16K words of user memory.
What communication ports does it have?
Built-in Data Highway Plus (DH+) and RS-232.
Is the 1747- still in production?
No. Rockwell Automation discontinued the SLC 500 processors (including the 1747-) at the end of 2021. It is now a legacy/spare part.
What software is used to program it?
RSLogix 500.
How many I/O points can it control?
Up to 4096 discrete inputs and 4096 discrete outputs, plus up to 480 analog points.
What is the difference between , L542, and L543?
All are SLC 5/04 processors. The difference is memory size: = 16K, L542 = 32K, L543 = 64K words.
