Product Overview
The 1747-L541 is an Allen-Bradley SLC 5/04 processor module for the SLC 500 Modular Hardware platform. It carries 16 KB of battery-backed RAM, a built-in Data Highway Plus (DH+) channel, and a 9-pin RS-232 port. The module handles up to 4096 inputs and 4096 outputs, with an analog I/O count of 480 and an I/O scan time of 0.225 milliseconds. This is the processor that keeps mid-size distributed control architectures running.
Technical Specifications
Memory and Program Capacity
With 16,000 words of user memory, the 1747-L541 gives you room for substantial ladder logic without constant housekeeping. A 1747-M13 flash-based memory device handles program and data table storage. Battery backup runs through a 1747-BA, so your program survives power interruptions.
Scan Time and Throughput
A program scan time of 0.9 milliseconds per keyword keeps execution tight. The I/O scan time of 0.225 milliseconds means the processor refreshes real-world signals quickly. For medium applications, that combination delivers predictable, repeatable cycle times.
Communication Ports
The DH+ channel supports extended-distance, multi-drop topology. The RS-232 port is configurable for DF1 and DH-485 peer-to-peer networks. Default RS-232 settings are 19.2 Kbaud, CRC error check, duplicate packet detect on, no parity, and no handshaking. DH+ defaults to 57.6 Kbaud with node address 1.
Industrial Applications
HVAC and SCADA Control
Building automation and utility SCADA systems rely on the SLC 500 family for dependable control. The 1747-L541 fits these environments because its DH+ channel reaches across long cable runs without extra hardware.
Material Handling
Conveyor and sortation lines need fast I/O response. The 0.225 millisecond I/O scan time keeps diverters and sensors synchronized. Distributed I/O racks connect through a communication adapter on the CPU rack and a scanner on the I/O racks.
Medium Distributed I/O Systems
When your application outgrows a single rack, the 1747-L541 supports distributed I/O across multiple chassis. This is a practical replacement path for aging SLC 5/03 installations that need more memory and faster communication.
Installation and Setup
Mount the processor in an SLC 500 rack. A system power supply is required to feed the internal circuitry through the electronic backplane. The front panel includes a 3-position key switch for Run, Remote, and Program modes. Six LED indicators — RUN, FLT, BATT, FORCE, DH+, and RS-232 — give you immediate diagnostic feedback. The module supports three I/O chassis with up to 30 module slots total.
Compatibility and Integration
The 1747-L541 supports remote I/O, DeviceNet pass-through, and indirect addressing. For RS-232 multi-drop networks, a 1761-NET-AIC lets the serial port join a DH-485 network. The processor also provides a 1-millisecond Selectable Timed Interrupt (STI) and a 0.5-millisecond Discrete Input Interrupt (DII) for time-critical tasks.
Integration Note
Wiring into DH+ or DH-485 networks may require an external gateway or connection module. Confirm cables and gateways with your supplier before commissioning.
Selection Guide
Before ordering, verify your rack type, power supply capacity, and communication topology. The 1747-L541 draws 1 Amp at 5 Volts DC and 200 mA at 24 Volts DC from the backplane. If you run distributed I/O, confirm adapter and scanner compatibility. Oil AutoTech offers hands-on technical selection help and fast-dispatch spares for oil, gas, and industrial automation. Contact Oil AutoTech today for pricing and availability.
Please verify current lifecycle status and availability with Oil AutoTech before ordering.
