Allen-Bradley 1756-L71S GuardLogix 5570 Safety Controller 2MB

1756-L71S Allen-Bradley GuardLogix 5570 Safety Controller

Technical Specifications

The Allen‑Bradley 1756‑L71S offers a comprehensive set of technical parameters that make it suitable for diverse industrial environments.

• User Memory: 2 MB for standard control logic, data tables, and application programs.

• Safety Memory: 1 MB physically separated for safety‑related logic and configurations.

• I/O Memory: 0.98 MB dedicated to I/O data handling and buffering.

• Non‑volatile Memory: Ships with a 1784‑SD1 1 GB SD card; upgradable to 2 GB using 1784‑SD2.

• Maximum Digital I/O: Supports up to 128,000 discrete I/O points for large‑scale systems.

• Maximum Analog I/O: Handles up to 4,000 analog I/O channels for process control.

• Task Capacity: Supports 31 standard tasks and 1 safety task simultaneously.

• Programs Per Task: Each task can contain up to 100 programs.

• Built‑in Communication: One USB 2.0 full‑speed port for local programming and firmware updates.

• Optional Communication Adapters: Supports EtherNet/IP, ControlNet, and DeviceNet via additional modules.

• Controller Connections: Up to 500 total connections, depending on network adapter selection.

• Redundancy: Not supported; this model is designed for single‑controller applications.

Electrical & Power Parameters

Understanding the power requirements of the 1756‑L71S ensures stable operation within your chassis.

• Current Draw (1.2V DC): 5 mA – minimal load on the backplane.

• Current Draw (5.1V DC): 800 mA – moderate consumption typical for high‑performance processors.

• Power Dissipation: 2.5 W, contributing to low heat output.

• Thermal Dissipation: 8.5 BTU/hr – easily managed within standard ControlLogix cabinets.

• Isolation Voltage: 30 V continuous, providing basic insulation between internal circuits and external connections.

• Enclosure Type: Open‑style (none) – designed for installation inside a protected ControlLogix chassis.

• Energy Storage: Uses capacitor modules (1756‑ESMCAP / 1756‑ESMCAPK) instead of lithium batteries, eliminating battery replacement concerns.

Mechanical & Environmental Parameters

The 1756‑L71S is built to withstand typical factory floor conditions while maintaining high reliability.

• Operating Temperature: 0 °C to 60 °C (32 °F to 140 °F) for consistent performance.

• Storage Temperature: -40 °C to 85 °C (-40 °F to 185 °F) for safe warehousing.

• Relative Humidity: 5% to 95% non‑condensing, suitable for humid environments.

• Shock Resistance: 30 g peak acceleration for 11 ms – meets industrial durability standards.

• Vibration Resistance: 2 g at 10‑500 Hz, ensuring stable operation near heavy machinery.

• Weight: 0.55 lbs (0.25 kg) – lightweight and easy to handle during installation.

• Compatible Chassis: Fits all ControlLogix 1756 series chassis, including 1756‑A4, A7, A10, A13, A17, and their K‑versions.

Installation Guidelines

Proper installation of the Allen‑Bradley 1756‑L71S ensures optimal performance and safety compliance.

• Chassis Slot: Install the controller in any available slot within a ControlLogix chassis; slot 0 is often preferred for system organization.

• Safety Partner: For SIL 3/Cat. 4 applications, insert the 1756‑L7SP safety partner module in the adjacent slot. The partner is automatically configured by the primary controller.

• SD Card: Ensure the pre‑installed 1784‑SD1 SD card remains inserted at all times. This card stores diagnostic data essential for Rockwell Automation support. Use only Rockwell‑approved SD cards to avoid data corruption.

• USB Connection: The front USB port allows direct connection to a programming laptop for online editing and configuration.

• Grounding: Properly ground the chassis to prevent electrical noise and ensure stable backplane communication.

• Energy Storage Modules: The controller ships with three capacitor modules – two removable and one non‑removable (1756‑ESMNRM / 1756‑ESMNRMK) that also prevents unauthorized USB access.

• Network Adapters: For EtherNet/IP, ControlNet, or DeviceNet communication, install the appropriate 1756 series communication module in the same chassis.

Packaging List

Each new 1756‑L71S unit includes the following items in the box:

• 1 x Allen‑Bradley 1756‑L71S GuardLogix 5570 processor module

• 1 x Pre‑installed 1784‑SD1 1 GB Secure Digital card

• 2 x Removable capacitor modules (energy storage)

• 1 x Non‑removable 1756‑ESMNRMK capacitor module (USB lock)

• 1 x Bus lever assembly for chassis mounting

• 1 x Quick‑start installation guide (printed)

Note: Communication adapters, power supplies, and mounting hardware are sold separately.

Shipping & Delivery

All orders for the 1756‑L71S are processed and shipped within 24 hours of order confirmation. We utilize FedEx, UPS, or DHL for global delivery, depending on your location and preference. Tracking information is sent via email once the shipment is dispatched. Estimated delivery time is 3‑7 business days for most regions, with expedited shipping options available at checkout.

Frequently Asked Questions (FAQ)

1. Can the 1756‑L71S operate without the safety partner module?
Yes, the 1756‑L71S can function as a standard ControlLogix controller without the safety partner. However, safety functions and SIL 3/Cat. 4 compliance require the 1756‑L7SP module to be installed.

2. Is the 1784‑SD1 card mandatory for operation?
Yes, the 1756‑L71S requires the SD card to remain inserted because it stores diagnostic data used by Rockwell Automation for troubleshooting. Removing it may cause loss of critical diagnostic information.

3. What programming languages are supported for safety tasks?
For safety logic, the Allen‑Bradley 1756‑L71S permits only Relay Ladder Logic (RLL). Standard tasks can be programmed using Ladder Diagram, Structured Text, Function Block Diagram, and Sequential Function Chart.

4. Can I use a third‑party SD card with this controller?
Rockwell Automation strongly recommends using only their approved SD cards (1784‑SD1 or 1784‑SD2). Third‑party cards have not been tested for compatibility and may lead to data corruption or system faults.

5. Does the 1756‑L71S support controller redundancy?
No, the 1756‑L71S does not support redundancy. For redundant applications, consider other GuardLogix models specifically designed for that purpose.