Overview
Allen-Bradley 1747-L511 is an SLC 5/01 processor unit designed for the SLC500 modular hardware platform. It is the entry-level processor in the modular SLC 500 series, featuring 1K user memory and a built-in DH485 communication interface. This processor is suited for applications including small process control, material handling, HVAC systems, and general discrete I/O control tasks.
Key Features
- Entry-level modular processor for SLC500 systems with 1K user memory
- Built-in DH485 communication (node-to-node messaging only; does not support Remote I/O topology)
- Supports up to 3,940 total discrete I/O signals with local I/O addressing
- LED status indicators: RUN, CPU FAULT, FORCED I/O, and BATTERY LOW
- Capacitor backup memory (non-battery backup like SLC 5/02 and 5/03); optional 1747-BA battery module
- Scan time: 8 milliseconds per keyword (program), 2.6 milliseconds I/O scan
Technical Specifications
- User Memory: 1,000 instructions (1 KB)
- Maximum Local Digital I/O: 960 points
- Maximum Analog I/O: 480 points
- Total I/O Capacity: 3,940 discrete signals
- I/O Chassis Support: Maximum 3 local SLC500 chassis
- Module Slots per Chassis: 30 slots available
- Communication: DH485 (9-pin connector)
- Backplane Current: 350 mA at 5V DC, 105 mA at 24V DC
- Operating Temperature: 0–60°C (32–140°F)
- Program Scan Time: 8 ms/K
- I/O Scan Time: 2.6 ms
- Certifications: UL listed (US/Canadian Safety Standards), CE compliant, C-Tick marked
Typical Applications
The 1747-L511 processor is well-suited for:
- Small Process Control: Basic sequential and analog control tasks with moderate I/O counts
- Material Handling: Conveyor systems, sorting, and automated material movement
- HVAC Systems: Temperature and humidity control in commercial and industrial buildings
- Discrete Manufacturing: Small-to-medium production lines and assembly operations
- SCADA Integration: Standalone or distributed throughout a facility for supervisory control
Limitation: This processor does not support Remote I/O networking. For Remote I/O capability, upgrade to the 1747-L531 or higher-tier SLC 5/02+ processors.
Compatibility & Replacements
Compatible With
- SLC500 modular hardware chassis and frame-based systems
- Over 60 different SLC500 I/O modules (digital, analog, communication modules)
- DH485 network communication at node level
- Allen-Bradley industrial control software (RSLogix 500)
- Standard SLC500 power supplies and I/O backplanes
Replaces / Drop-In Replacement For
The 1747-L511 is the direct replacement for previous revisions and series variants of the same model. It is not a drop-in replacement for higher-capacity processors such as:
- 1747-L514 (SLC 5/02, 4K memory, Remote I/O capable)
- 1747-L531 (SLC 5/02, 4K memory, Remote I/O capable)
- 1747-L541 (SLC 5/03, 8K memory)
- 1747-L551 (SLC 5/04, 16K memory, Ethernet/RS-232)
- 1747-L561 (SLC 5/05, 32K memory, Ethernet)
Verify compatibility with your system integrator before ordering if upgrading from a higher-tier processor.
Works With
- RSLogix 500: Ladder and structured text programming
- DH485 Network: Node-to-node communication for peer messaging (passive mode only)
- 1747-KE Interface: Bridge from DF1 (full-duplex or half-duplex slave) to DH485
- EEPROM Backup Memory: Non-volatile memory backup option
- 1747-BA Optional Battery Module: Extended memory backup protection
- Standard SLC500 I/O modules: Digital input, digital output, analog input, analog output modules
