Purchase now: Allen Bradley 1747-L524 SLC 5/02 Processor
Purchase now: Atlantechdrives provides you the 1747-L524, an advanced CPU processor from the highly respected Allen Bradley SLC 5/02 family. While the 5/01 series is strictly for basic boolean logic, the 1747-L524 represents a massive leap in capability for the legacy SLC 500 platform. Engineered with 4K of user memory, this processor unlocks a significantly expanded instruction set, including advanced mathematical computations, FIFO/LIFO shift registers, and most importantly, native PID (Proportional-Integral-Derivative) loop capabilities. This makes the 1747-L524 the ideal replacement controller for legacy manufacturing environments that require precise closed-loop temperature, flow, or pressure control without migrating to a completely new automation architecture.
Technical Specifications of the 1747-L524
The 1747-L524 provides enough processing power and memory space to handle hundreds of rungs of complex ladder logic. Like its predecessor, it features a single RJ45 port for DH-485 network communication, allowing integration with legacy PanelView standard HMIs.
- Part Number: 1747-L524
- Processor Class: SLC 5/02 CPU
- Total User Memory: 4K Words (Instructions and Data)
- Communication Port: DH-485 via RJ45 jack
- Instruction Set: Includes PID, FIFO, LIFO, and advanced math
- Maximum Local I/O Capacity: 4096 inputs / 4096 outputs
- Maximum Local Chassis: 3 (Up to 30 slots total)
- Backplane Current Draw: 350 mA at 5V DC, 105 mA at 24V DC
Expert Tips: Programming PID and Math Limitations
While the 1747-L524 is a capable processor, it requires specific programming techniques. Expert Tip: Although the SLC 5/02 supports PID instructions for closed-loop control, it does not support floating-point (Real) math. If you are reading a 4-20mA signal from a 1746-NI4 analog module, you cannot scale it directly into a decimal value like «45.2 PSI». You must utilize integer math (multiplying and dividing whole numbers using standard N7 data files) to scale your process variables. When tuning the PID block on the 5/02, remember that your Setpoint (SP) and Process Variable (PV) must both be scaled integers (typically 0 to 16383). Transitioning programmers accustomed to modern ControlLogix systems often overlook this legacy integer scaling requirement.
Maintenance and Firmware Differences
When replacing a failed 1747-L524 in the field, always check the firmware series (Series A, B, or C) printed on the side label of the old unit. While newer series are generally backward compatible, replacing a Series C with a refurbished Series A might result in missing minor instructions or DH-485 communication glitches with newer networking hardware. Furthermore, to connect your modern Windows laptop to program this processor, you cannot use a direct cable; you must use an Allen Bradley 1747-UIC (USB to DH-485) interface converter to safely translate the protocols.
Frequently Asked Questions (FAQs)
Q: Does the SLC 5/02 allow for online programming edits?
A: No. Just like the 5/01, the SLC 5/02 architecture does not support online editing. You must switch the machine to «Program» mode (stopping the logic scan) to download any code modifications, and then switch back to «Run» mode.
Q: How long does the internal battery last?
A: The standard 1747-BA lithium battery typically retains the 4K RAM memory for 2 to 5 years, depending on ambient temperature and how often the main chassis power is turned off. Always replace it while the PLC power is ON to prevent memory loss.
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This 4KB SLC 5/02 CPU offers enhanced instruction sets when mounted in a 1746-A7 7-slot chassis.
