The Allen-Bradley 1747-L542, also cataloged as the 1747-L542 Processor Module, operates as a dedicated hardware component for central logic execution and I/O scan management within SLC 500 rack assemblies.
Hardware Specifications
Parameter
Specification
Brand
Allen-Bradley
Model
1747-L542
Origin
USA
Weight
0.68 kg (1.50 lbs)
Dimensions
Single-slot SLC 500 chassis footprint
Operating Temp
0 to 60 deg C
Power Consumption
4 W total power
User Memory
32K words
Max Discrete I/O Capacity
4096 inputs, 4096 outputs
Max Local Chassis Support
Up to 3 chassis (30 total slots)
Program Execution Speed
0.9 ms/K typical scan time
Programming Instruction Set
107 instructions
Operating Shock Rating
30 G
Relative Humidity
5 to 95% non-condensing
Storage Temperature
-40 to 85 deg C
Deterministic Backplane & EtherNet/IP Networks
The processor executes real-time ladder logic and control loops across a maximum addressable field I/O space of 4096 discrete inputs and 4096 discrete outputs. Internal firmware flash compatibility ensures synchronized cyclic scanning of local backplane modules across up to 3 interconnecting chassis frames (30 total slots). High-speed data processing algorithms deliver a execution scan time of 0.9 ms per kiloword, maintaining deterministic network data exchange without adding latency across connected industrial communication channels.
Frequently Asked Questions
Q: What is the maximum physical expansion limit supported by the 1747-L542 in a local rack setup?
A: The processor supports local expansion across a maximum configuration of 3 chassis or up to 30 total I/O module slots.
Q: What power consumption overhead must be calculated for the chassis power supply?
A: The module exhibits a continuous total power dissipation rating of 4 W from the chassis backplane.
Q: How does the 1747-L542 perform under high mechanical shock conditions?
A: The hardware architecture is designed and tested to withstand continuous operational mechanical shock loads up to 30 G.
Field Installation Guidelines
Verify that the SLC 500 chassis power supply is completely powered down before installing or removing the CPU module. Align the 1747-L542 circuit board with the guide rails in Slot 0 of the master chassis, sliding the module inward until top and bottom lock levers snap into place.
Establish low-impedance grounding by securing the chassis frame directly to the enclosure mounting panel with clean metal-to-metal contact. Route all peripheral serial and communication cables away from high-voltage AC lines and variable frequency drives using separated wire channels. Observe proper electrostatic discharge precautions when handling the exposed card edge connectors to avoid component degradation.
