Allen-Bradley 1747-L514 SLC 5/01 Processor

The Allen-Bradley 1747-L514, also cataloged as the 1747-L514 SLC 5/01 Processor, serves as the primary SLC 5/01 CPU module utilized to execute cyclic scan control, I/O image table management, and DH-485 network coordination across Rockwell Automation SLC 500 modular chassis systems. The processor operates as slot 0 controller with integrated memory execution and embedded serial communication handling.

Suffix Breakdown & Model Matrix

The base model 1747-L514 does not include functional suffix segmentation. It is a fixed configuration SLC 5/01 processor variant with 4K user memory and integrated DH-485 communication interface.

Hardware Specifications

Backplane Bus Execution and DH-485 Control Architecture

Within Rockwell Automation SLC 500 backplane systems, the 1747-L514 executes deterministic scan-based control using capacitor-backed RAM for cyclic program execution. The processor occupies slot 0 and coordinates all I/O modules through backplane image table synchronization.

The integrated DH-485 interface operates as a serial token-based communication node, supporting master/slave exchanges for programming, monitoring, and data transfer via RSLogix 500 environments. Backplane arbitration ensures that I/O updates are synchronized at defined scan intervals, with 2.6 ms I/O scan timing and 8 ms program scan execution cycles under nominal load.

Memory architecture is split between volatile program execution space (4K instructions) and EEPROM-backed retention storage via 1747-M1/M2 expansion modules, enabling structured program retention across power cycles without runtime execution dependency on non-volatile memory.

Frequently Asked Questions (FAQ)

Q: Does the 1747-L514 support hot-swapping in the SLC 500 chassis?
A: No. The processor must be inserted or removed with chassis power removed to prevent backplane signal corruption.

Q: What is the function of slot 0 assignment?
A: Slot 0 defines the primary CPU position responsible for backplane arbitration and I/O image table coordination across all modules.

Q: Can the DH-485 interface operate independently of the CPU scan cycle?
A: No. DH-485 communication is synchronized with processor execution and depends on CPU scheduling and backplane servicing.

Field Installation Guidelines

The module shall be installed exclusively in slot 0 of a 1746 chassis. Backplane connectors must be fully seated to ensure correct 5 VDC and communication bus alignment prior to power application.

DH-485 cabling must follow shielded twisted pair routing practices with correct termination and grounding at a single reference point. Cable routing must be separated from high-noise conductors to maintain serial signal integrity.

EEPROM memory modules, if used, must be inserted only under de-energized conditions to prevent corruption of stored program data.