Purchase now: Allen Bradley 1747-L40E Fixed Controller
Purchase now: Atlantechdrives provides you the 1747-L40E, the flagship high-speed, high-density «Fixed Hardware Style» programmable controller from the Allen Bradley SLC 500 family. Built for the most demanding discrete automation tasks, the 1747-L40E maximizes the brick footprint by offering 40 total I/O points: 24 responsive 24V DC Sinking inputs and 16 ultra-fast DC Transistor Sourcing outputs. This solid-state DC architecture completely eliminates the mechanical delay of traditional relays, making the 1747-L40E the ultimate standalone controller for high-speed filling machines, rapid packaging diverters, and precision cut-to-length systems that require split-second actuation and precise rotary encoder tracking via its embedded high-speed counter.
Technical Specifications of the 1747-L40E
The 1747-L40E is a powerhouse of self-contained automation. It runs on standard 120/240V AC factory line voltage and includes an isolated 24V DC user power supply to directly drive your photoelectric sensors and proximity switches.
- Part Number: 1747-L40E
- Controller Type: Fixed Hardware Style (Maximum footprint)
- Total I/O Points: 40 Points
- Inputs: Twenty-four (24) 24V DC Sinking (NPN logic)
- Outputs: Sixteen (16) 24V DC Transistor Sourcing (PNP logic)
- Line Power Requirement: 120 / 240V AC
- Memory Capacity: 1K Instructions
- Communication Port: DH-485 (RJ45 jack)
- Special Feature: Embedded High-Speed Counter (HSC)
Expert Tips: Transistor Sourcing and Short Circuits
The 16 solid-state transistor outputs on the 1747-L40E are incredibly fast, but they require precise electrical care. Expert Tip: These are «Sourcing» outputs, meaning when the PLC turns an output ON, it pushes +24V DC out to the field device. If a cable gets crushed on the factory floor and shorts that +24V directly to ground, the high-speed transistor will blow instantly, permanently ruining that output point (unlike a relay, which might survive a brief short). Because fixed controllers do not have replaceable output cards, losing a transistor is a major setback. You must install externally fused terminal blocks (typically 0.5A fast-blow) between the PLC outputs and the field wiring to protect the internal silicon from factory floor shorts.
Installation Advice: Wiring the High-Speed Counter
To utilize the embedded High-Speed Counter for rotary encoders, you must wire your encoder’s A and B pulse channels into the specific designated high-speed input terminals on the controller (typically inputs 0, 1, 2, or 3, depending on your manual’s schematic). Standard input terminals process signals too slowly for rapid counting. Furthermore, ensure the encoder’s power supply is grounded to the same potential as the PLC’s DC common to prevent common-mode noise from introducing false counts into the accumulator.
Frequently Asked Questions (FAQs)
Q: Can I connect 120V AC actuators to the outputs of the 1747-L40E?
A: No. The outputs are 24V DC solid-state transistors. Connecting 120V AC to these terminals will cause an immediate catastrophic failure. If you need to switch AC loads, you must wire the transistor output to a 24V DC relay coil, and let the relay’s contacts switch the 120V AC.
Q: Does this controller support Online Editing?
A: No. Like all SLC 500 fixed hardware controllers, you must switch the machine to PROGRAM mode to download logic changes, which will temporarily halt the machine.
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This SLC 500 fixed controller provides robust logic; for easy programming and diagnostics, we recommend using the 1747-UIC USB interface converter.
