Product Details
Overview
The Allen-Bradley 1785-LT is a high-performance PLC-5/15 processor module designed for the Classic PLC-5 series. It provides fast logic execution and supports both local and remote I/O expansion, delivering reliable performance for complex industrial control systems. The module is engineered for durability and long-term operation in harsh industrial environments.
Technical Specifications
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Model Number: 1785-LT
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Brand / Series: Allen-Bradley PLC-5
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Module Type: Processor Module
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Weight: 3.06 lbs (1.39 kg)
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Embedded RAM: 6K Words, expandable up to 14K Words
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Memory Expansion Modules: 4K RAM (1785-MR), 8K RAM (1785-MS), 8K EEPROM (1785-MJ)
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Battery: 1770-XY
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Program Scan Time: 2 ms/K words (bit logic), 8 ms/K words typical
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Supported Local I/O: Up to 4 racks (1 resident rack)
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Supported Remote I/O: Up to 3 remote racks
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I/O Capacity: 512 inputs + 512 outputs using 16 or 32-pt modules
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Max Total I/O: 3072 (any mix) or 3072 in + 3072 out (complementary)
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Analog I/O Capacity: 512, Max Analog I/O: 3072
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DH+ Channel: Yes
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Remote I/O Channel: Yes
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Hardware Addressing: 2-slot, 1-slot, ½ slot
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Module Location: 1771-I/O chassis, left-most slot
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Keying: Between 40–42; Between 54–56
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I/O Scan Time Per Rack: 10 ms @ 57.6 kbits/s, 7 ms @ 115.2 kbits/s, 3 ms @ 230.4 kbits/s
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Max I/O Chassis Total: 93
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Max I/O Chassis Extended Local: 0
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Max I/O Chassis Universal Remote: 32 max per I/O link
Key Features
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High-Speed Processing: Optimized 6K Words SRAM with up to 14K expansion for large programs.
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Comprehensive I/O Support: Supports local and remote I/O expansion with up to 3072 points.
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Built-In Communication: DH+ and standalone scanner for local/remote I/O ensures seamless integration.
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Flexible Memory Options: Supports RAM and EEPROM modules for data retention and program storage.
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Industrial Durability: Designed for 1771-I/O chassis with long-term stability in industrial environments.
Applications
The 1785-LT is suitable for:
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Manufacturing automation and process control
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Data acquisition and SCADA systems
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Large-scale PLC networks with multiple local and remote racks
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Critical industrial applications requiring high-speed I/O processing
Similar Models
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1785-LP – Smaller memory PLC-5/10 module, lower I/O capacity.
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1785-LT – Standard PLC-5/15 processor with 6K SRAM, expandable up to 14K.
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1785-LX – High-capacity PLC-5/20 processor module for extended I/O and memory requirements.
FAQ
Q: How many I/O points can the 1785-LT module manage?
A: It can handle up to 512 inputs and 512 outputs per module, with a maximum total I/O of 3072.
Q: Can the embedded RAM be expanded?
A: Yes, the 6K Words SRAM can expand up to 14K Words using memory modules.
Q: What chassis does this module fit into?
A: It is designed for the 1771-I/O chassis, occupying the left-most slot.
Q: Does it support remote I/O?
A: Yes, it can interface with up to 3 remote racks via DH+ channels.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.































