Allen-Bradley 1768-L45S Compact GuardLogix Controller

1768-L45S Allen-Bradley Compact GuardLogix Safety Controller

Product Introduction

The 1768-L45S controller belongs to the Allen-Bradley Compact GuardLogix product family. It combines standard automation capabilities with integrated safety functionality in a single compact package. Manufacturers choose this controller for applications that demand high-level machine safety alongside routine control tasks.

This controller provides 3MB of standard memory for user programs and data. Additionally, it includes 1MB of dedicated safety memory for safety-related logic and monitoring functions. The 1768-L45S implements 1oo2 (one-out-of-two) safety architecture, delivering reliable safety performance.

With SIL 3 (Safety Integrity Level 3) and PLe (Performance Level e) certification, this controller meets the most stringent safety standards. It works seamlessly with various communication networks, including Ethernet/IP, ControlNet, and DeviceNet.

Technical Specifications

The 1768-L45S offers comprehensive specifications for demanding safety applications.

Key parameters include:

• Manufacturer: Allen-Bradley

• Part Number: 1768-L45S

• Product Line: Compact GuardLogix

• Module Type: Processor Module (Safety)

• Standard Memory: 3 MB

• Safety Memory: 1 MB

• Safety Architecture: 1oo2

• Safety Rating: SIL 3, PLe

• Backplane Current: 2.1 Amps at 24 Volts

• Power Consumption: 50.4 Watts maximum

• Power Dissipation: 9.5 Watts

• Isolation Voltage: 30 Volts Continuous (tested at 500V DC for 6s)

• Operating Temperature: 0° to +60°C (+32° to +140°F)

• Storage Temperature: -40° to +85°C (-40° to +185°F)

• Relative Humidity: 5% to 95% non-condensing

• Vibration Resistance: 5G at 10–500 Hz

• Operating Shock: 30G

• Non-Operating Shock: 50G

• Enclosure Rating: Open type

Memory and Safety Features

The 1768-L45S stands out with its dual-memory architecture. The 3MB standard memory handles general control logic, process automation, and data management. The 1MB safety memory manages critical safety functions, emergency stop routines, and monitoring tasks.

This separation ensures that safety routines remain isolated from standard operations. The 1768-L45S also supports an optional 1784-CF128 CompactFlash memory card for program backup and data transfer.

For safety programming, use relay ladder language and dedicated safety application instructions. Standard tasks can be programmed using languages defined in the IEC-61131-3 standard, including Ladder Logic, Function Block, and Structured Text.

Communication and Networking

The 1768-L45S includes an embedded RS232 serial port for programming and diagnostics. This port supports communication speeds up to 38.4 Kbps and works with DF1 protocols.

Furthermore, this controller supports up to two 1768 communication modules. You can install various module types, including:

• Ethernet/IP standard and safety modules

• ControlNet standard and safety modules

• DeviceNet modules

This flexibility allows the 1768-L45S to integrate with diverse network architectures. Whether you need standard communication or safety-rated networks, this controller accommodates your requirements.

I/O Expansion Capabilities

The 1768-L45S supports extensive I/O expansion for medium to large control systems.

Specifically, the controller handles up to 30 1769 Compact I/O modules distributed across three expansion banks. Additionally, it supports up to four 1768 local I/O modules.

When planning your system, consider the backplane current requirements. The 1768-L45S draws 2.1 Amps at 24 Volts from the backplane. This capacity supports a wide range of digital, analog, and specialty I/O modules.

Installation and Mounting Guidelines

Installing the 1768-L45S requires careful attention to clearances and environmental conditions.

Mounting options include DIN rail or panel installation. For panel mounting, use appropriate screws and ensure a flat, secure surface.

Maintain proper clearances around the controller for adequate ventilation:

• Top and bottom clearance: 105 mm (4.13 inches)

• Side clearance: 90 mm (3.54 inches)

These clearances promote proper air circulation and maintain the operating temperature within the 0° to 60°C range. For extreme environments, consider installing climate control devices such as heaters or fans.

Environmental and Safety Certifications

The 1768-L45S carries important certifications for global use. Its SIL 3 and PLe ratings confirm compliance with international safety standards.

The controller meets CISPR 11 Group 1, Class A emission standards for industrial environments. It also holds cUL-us certification, validating compliance with US and Canadian safety requirements.

With a T4 temperature code (135°C), the 1768-L45S operates reliably in various industrial settings. Its vibration and shock tolerance ensures durability in demanding conditions.

Packaging and Shipping

Each 1768-L45S ships in protective packaging to ensure safe delivery. The package includes the controller module only.

We do not include power supplies, cables, CompactFlash cards, mounting hardware, or programming software. These accessories must be ordered separately based on your system requirements.

We ship all orders via FedEx, UPS, or DHL. Choose your preferred carrier at checkout. Delivery times vary by destination, but most orders arrive within 3–7 business days.

Frequently Asked Questions

1. What safety rating does the 1768-L45S hold?
The 1768-L45S meets SIL 3 (Safety Integrity Level 3) and PLe (Performance Level e) requirements.

2. How much memory does the 1768-L45S provide?
This controller offers 3MB of standard memory plus 1MB of dedicated safety memory.

3. How many I/O modules can the 1768-L45S support?
The 1768-L45S supports up to 30 1769 Compact I/O modules across three banks and up to four 1768 local I/O modules.

4. What programming languages does the 1768-L45S support?
Standard tasks use IEC-61131-3 languages. Safety tasks require relay ladder language with safety application instructions.

5. What is the operating temperature range for the 1768-L45S?
The 1768-L45S operates from 0° to +60°C (+32° to +140°F) with 5% to 95% non-condensing humidity.