Overview
The Allen-Bradley 1747-L524 is a modular SLC 5/02 processor unit within the SLC 500 family, delivering reliable, mid-range controller performance for general-purpose industrial automation. With 4KB user memory and support for up to 4096 discrete I/O points, the 1747-L524 serves applications ranging from machine control to process automation. Its compact form factor and proven firmware make it a drop-in replacement for legacy systems and a cost-effective choice for new installations.
Key Features
- 4KB Integrated Memory — User-configurable for program or data storage; supports EEPROM backup with battery-backed RAM (lithium battery option: 5-year retention)
- 4096 I/O Addressing — Up to 4096 discrete input points and 4096 output points; maximum 480 local analog I/O
- DH485 Communication Port — Built-in serial interface for messaging to other PLC5, CompactLogix, and ControlLogix controllers; SCADA and HMI integration
- Advanced Instruction Set — 71 programming instructions including PID algorithm, indexed addressing, program interrupts, and 32-bit signed arithmetic
- Modular I/O Support — Compatible with 60+ I/O modules: analog, digital, scanner (DeviceNet, ControlNet, Universal Remote I/O), specialty, and intelligent modules
- Fast Scan Performance — 4.8 ms program scan time (per 1K instructions) and 1.6 ms I/O scan time for responsive control
Technical Specifications
- Processor Type: SLC 5/02 (SLC 500 modular)
- Memory: 4K (4,000 instructions), configurable for program/data; EEPROM backup capability
- Discrete I/O Capacity: 4096 inputs + 4096 outputs
- Analog I/O: Maximum 480 local analog I/O
- Communication: DH485 serial port (RS-485)
- Program Scan Time: 4.8 ms/K typical instruction mix
- I/O Scan Time: 1.6 ms
- Bit Execution: 2.4 µs
- Backplane Current Load: 350 mA @ 5V DC; 105 mA @ 24V DC
- CPU Current Draw: 90 mA @ 5V DC
- Power Loss Hold-up: 20 ms to 3 s (dependent on supply loading)
- Operating Temperature: 0°C to 60°C (32°F to 140°F)
- Humidity: 5% to 95% RH, non-condensing
- Dimensions: 145 mm (H) × 35 mm (W) × 142 mm (D)
- Mounting: Rack-mount with standard SLC 500 chassis/backplane (3 chassis, 30 slots max per system)
- Battery: User-replaceable lithium battery (estimated 2–5 year life); capacitor option available
- Status Indicators: LED indicators for run/fault/power; battery low warning
Typical Applications
- Discrete Manufacturing — Pump/motor control, conveyor systems, press operation sequencing
- Process Control — Closed-loop PID applications, temperature/pressure regulation, batch processing
- Machine Control — Multi-axis motion coordination, position feedback handling, interlock logic
- Legacy System Integration — Drop-in replacement for failed SLC 5/02 units; bridges to modern ControlLogix architectures via networked I/O
- Remote I/O Supervision — Centralized control of distributed field I/O over DH485 scanner modules
Compatibility & Replacements
The 1747-L524 is the only variant in the SLC 5/02 processor line and is 100% compatible with the SLC 500 modular hardware ecosystem. Supported I/O modules include all 60+ analog, digital, scanner, and specialty card types designed for SLC 500 platforms. Scanner modules (DeviceNet, ControlNet, Universal Remote I/O) are fully supported for remote I/O expansion; however, the 1746-BLM and 1746-MPM modules are not compatible. Programming is performed using RSLogix 500, PLC-500 A.I. series, HHT (handheld terminal), or APS software. The processor can be upgraded to higher-capacity models (e.g., 1747-L55 with 32K memory) if application growth demands exceed 4K memory or 4096 I/O points. Messaging compatibility extends to PLC 5 and ControlLogix systems for multi-controller coordination.
