PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1756-L74 is a ControlLogix controller designed for industrial automation applications. It occupies a single slot in any standard ControlLogix chassis. The unit provides 16 MB of user memory and 0.98 MB of dedicated I/O memory. Internal backplane power supports controller operation with 800 mA at 5.1 V DC. The unit also draws 5 mA at 1.2 V DC. This controller handles up to 128,000 total digital I/O points and 4,000 analog I/O points.
The controller eliminates maintenance batteries by using capacitor-based energy storage modules. A 1756-ESMCAP energy storage module comes pre-installed in the unit. These modules protect user RAM during power interruptions and are field replaceable. Non-volatile storage includes a 1 GB SD card with support for up to 2 GB. The controller features a front-facing USB port and supports 32 concurrent execution tasks.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
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| UPC | 612598876044 |
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| Weight | 1.31 lbs (0.60 kg) |
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| Maximum Analog I-O | 4000 |
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| Maximum I-O | 128000 |
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| Module Type | Processor Module |
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| Non-volatile memory | 1GB (ships with the controlelr) |
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| No. of task | 32 |
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| Programs per task | 100 Programs |
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| Event Task | All Triggers |
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| Built-in communication | 1 USB port |
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| Optional Communication adapters | • EtherNet/IP • ControlNet • DeviceNet • Data Highway Plus • Remote I/O • SynchLink • Third-party process and device networks |
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| Redundancy | Full Support |
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| Integrated Motion | • SERCOS interface • Analog options (encoder input, LDT input, SSI input) • Integrated Motion on the EtherNet/IP network |
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| I-O Memory | 0.98 MB |
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| User Memory | 16 MB |
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| Maximum Digital I-O | 128,000 |
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| Current Draw (1.2 Volts DC) | 5 milliamps |
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| Current Draw (5.1 Volts) | 800 milliamps |
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| Power Dissipation | 2.5 Watts |
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| Thermal Dissipation | 8.5 BTU per hour |
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| Isolation Voltage | 30 Volts Continuous |
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| Enclosure | None |
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TECHNICAL INFORMATION
Features
- 16 MB user memory and 0.98 MB dedicated I/O memory
- Capacitor-based energy storage module eliminating memory backup batteries
- Pre-installed 1756-ESMCAP energy storage module with field-replaceable design
- Ships with 1 GB Secure Digital non-volatile memory card
- Memory expandable up to 2 GB using 1784-SD2 card
- Single-slot chassis installation across standard ControlLogix frames
- Support for 32 execution tasks with up to 100 programs per task
- Integrated motion over EtherNet/IP, SERCOS interface, and analog options
- Full controller redundancy support for critical automation systems
TECHNICAL INFORMATION
Applications
- Factory automation systems with high digital and analog point counts
- Multi-axis motion control applications using EtherNet/IP or SERCOS interfaces
- Continuous process automation requiring controller and power supply redundancy
TECHNICAL INFORMATION
Connections / Interfaces
- One built-in USB 2.0 programming and configuration port
- 30 V continuous isolation between the USB port and system backplane
- Optional communication modules for EtherNet/IP, ControlNet, and DeviceNet
- Legacy network connectivity via Data Highway Plus and Remote I/O modules
- High-speed controller synchronization through optional SynchLink adapters
TECHNICAL INFORMATION
Installation Guidelines
- Install the controller into any available slot of a ControlLogix chassis.
- Verify system power supply capacity for 800 mA at 5.1 V DC backplane load.
- Operate within the rated temperature range of 0 to 60 degrees Celsius.
- Maintain clear airflow to dissipate 8.5 BTU per hour of heat.
TECHNICAL INFORMATION
Configuration Guidelines
- Develop program logic using relay ladder, structured text, function block, or sequential function charts.
- Assign up to 100 programs per task across 32 available execution tasks.
- Configure event-driven tasks using all supported system triggers.
- Upgrade non-volatile storage to 2 GB by inserting an optional 1784-SD2 card.
TECHNICAL INFORMATION
Compatibility
- Chassis compatibility: 1756-A4, 1756-A4K, 1756-A7, 1756-A7K, 1756-A10, 1756-A10K, 1756-A13, 1756-A13K, 1756-A17, and 1756-A17K
- Standard power supply compatibility: 1756-PA50, 1756-PA72, and 1756-PA72K
- Redundant power supply compatibility: 1756-PA75R, 1756-PA75RK, 1756-PB75R, 1756-PB75RK, 1756-PSCA2, and 1756-PSCA2K
- Energy storage modules: 1756-ESMCAP, 1756-ESMCAPK, 1756-ESMNSE, 1756-ESMNSEK, 1756-ESMNRM, and 1756-ESMNRMK
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSChassis compatibility: 1756-A4, 1756-A4K, 1756-A7, 1756-A7K, 1756-A10, 1756-A10K, 1756-A13, 1756-A13K, 1756-A17, and 1756-A17K Standard power supply compatibility: 1756-PA50, 1756-PA72, and 1756-PA72K Redundant power supply compatibility: 1756-PA75R, 1756-PA75RK, 1756-PB75R, 1756-PB75RK, 1756-PSCA2, and 1756-PSCA2K Energy storage modules: 1756-ESMCAP, 1756-ESMCAPK, 1756-ESMNSE, 1756-ESMNSEK, 1756-ESMNRM, and 1756-ESMNRMK
Verify compatibility against the exact Part Number, revision and manufacturer documentation before ordering.
PART VERIFICATION
Before You Order
Industrial automation parts can share similar model names, suffixes and revisions. Confirm the complete manufacturer Part Number before purchase.
01Check Part NumberMatch the complete ordering code on the existing unit.
02Confirm RevisionCheck suffix, hardware or firmware when applicable.
03Send a Label PhotoWe can review a clear label photo when identification is uncertain.
ORDERING PROCESS
From RFQ to Dispatch
1Submit Part Number2Verify Product Identity3Confirm Stock & Condition4Issue Quotation5Dispatch & Tracking
PRODUCT FAQ
Frequently Asked Questions
How does the Allen-Bradley 1756-L74 maintain RAM contents without batteries?
The 1756-L74 uses a capacitor-based energy storage module instead of a lithium battery. The pre-installed 1756-ESMCAP powers RAM data retention during system outages.
What non-volatile memory card comes standard with the 1756-L74?
The unit ships with a 1 GB 1784-SD1 Secure Digital card. Users can expand non-volatile memory to 2 GB using a 1784-SD2 card.
Which communication networks can the 1756-L74 support?
The controller connects to industrial networks through dedicated communication modules. Supported networks include EtherNet/IP, ControlNet, DeviceNet, Data Highway Plus, Remote I/O, and SynchLink.
What are the pricing and commercial terms for the 1756-L74?
Published market figures serve as indicative reference pricing only and do not represent a final quotation. Contact Aituos Controls for current stock and condition-based pricing.
