Product Overview

The Allen-Bradley 1756-L1 is a ControlLogix 5550 processor module. This controller has 64 KB of user memory. It supports up to 250 connections. The module installs directly into any slot of the ControlLogix chassis. You can place multiple controllers in the same chassis. Each controller operates independently. They communicate across the backplane when needed.

For inquiries, contact us at +86 158 8020 0923 (WhatsApp).

Part Number Breakdown (Tree Structure)

• 1756 → Series Family
  • ControlLogix platform
  • Allen-Bradley / Rockwell Automation
• L → Product Type
  • Logix controller (processor)
• 1 → Memory Size
  • 64 KB user memory
  • Early Logix 5550 series

Key Specifications

• Brand: Allen-Bradley / Rockwell Automation
• Part Number: Allen-Bradley 1756-L1
• Series: ControlLogix (Logix 5550)
• Module Type: Processor Module
• User Memory: 64 KB
• Maximum Connections: 250
• Slot Width: One slot
• Enclosure Type: Open

Memory and I/O Capacity

• Maximum Discrete I/O: 128,000 points
• Maximum Analog I/O: 4,000 points
• Nonvolatile Memory: Not included
• Use 1756-M1, 1756-M2, or 1756-M3 for nonvolatile storage.

Communication Port and Networks

• Built-in Port: One RS232 port
• Supported Networks: DeviceNet, ControlNet, DH+
• Supported Protocols: EtherNet/IP, RS-232-C (DF1/DH-485)
• Programming Cable: 1756-CP3 or 1747-CP3 serial cable

Power Consumption

• Backplane Current (5 VDC): 120 milliamps (0.12 A)
• Backplane Current (24 VDC): 2 milliamps (0.002 A)
• Peak Backplane Current (5V): 0.65 Amps
• Peak Backplane Current (24V): 0.02 Amps
• Power Dissipation (Average): 3.3 Watts
• Power Dissipation (Max at 60°C): 4.1 Watts
• Thermal Dissipation: 11.3 BTU/hour average

Isolation and Protection

• Isolation Voltage: 30 Volts continuous
• Minimum Operating Current: 2 mA at 10 VDC
• Maximum Operating Current: 3.5 mA at 30 VDC
• Maximum Off-State Input Current: 1.5 mA

Battery Backup

• Compatible Batteries: 1756-BA1 or 1756-BA2
• Battery type: 0.59g lithium battery
• Battery backs up RAM when power is off.

Compatible Memory Modules

• 1756-M1
• 1756-M2
• 1756-M3
• Do not use other memory modules.
• Wrong modules cause module failure.

Removable Terminal Blocks

• 1756-TBCH
• 1756-TBS6H

Compatible Chassis

• 1756-A4 (4-slot)
• 1756-A7 (7-slot)
• 1756-A10 (10-slot)
• 1756-A13 (13-slot)
• 1756-A17 (17-slot)

Environmental Specifications

• Operating Temperature: 0°C to 60°C (32°F to 140°F)
• Storage Temperature: -40°C to 85°C (-40°F to 185°F)
• Relative Humidity: 5% to 95% non-condensing
• Operating Shock: 30 G peak for 11 milliseconds
• Storage Shock: 50 G peak for 11 milliseconds
• Vibration: 10 to 500 Hz at 2.0 G peak acceleration

Programming Languages

• Ladder Diagram (LD)
• Function Block Diagram (FBD)
• Sequential Function Chart (SFC)
• Structured Text (ST)
• All languages follow IEC-61131-3 standards.

System Integration

• Controls medium-scale processes.
• Works with ControlLogix I/O modules.
• Works with Flex I/O and POINT I/O modules.
• Supports stand-alone and distributed I/O.
• Connect to HMI and SCADA systems via RS232.

Diagnostic Features

• Front panel has embedded LED indicators.
• LEDs show module status and faults.
• Use RSLinx Classic or Enterprise for configuration.
• Define communication drivers in RSLinx software.

Installation Guide

• Turn off all power before installation.
• Insert the Allen-Bradley 1756-L1 into any chassis slot.
• Press firmly until the processor seats in the backplane.
• Secure the module with the retaining screws.
• Connect programming cable to RS232 port.
• Use 1756-CP3 or 1747-CP3 serial cable.
• Apply power and check processor status LEDs.
• Configure communication using RSLinx software.
• Download your program using RSLogix 5000.

Battery Replacement

• Replace battery when LOW BAT LED lights.
• Use only 1756-BA1 or 1756-BA2 battery.
• Remove old battery carefully.
• Insert new battery with correct polarity.
• Dispose of old battery according to local regulations.

Maintenance Tips

• Check LED indicators for fault conditions.
• Monitor battery status annually.
• Replace battery every 1-2 years.
• Keep module free from dust and moisture.
• Perform regular program backups.
• Use nonvolatile memory module for program storage.

Troubleshooting Tips

• If OK LED is red, check power supply and backplane.
• If RS232 communication fails, check cable and settings.
• Verify RSLinx driver configuration is correct.
• Check battery if program lost after power cycle.
• Use RSLogix 5000 to view fault codes.

Package Contents

• One Allen-Bradley 1756-L1 processor module
• One battery (1756-BA1 or equivalent)
• One product label
• Memory modules and cables not included (order separately)

Warranty and Shipping

• 12 months factory warranty from shipment date.
• Warranty covers manufacturing defects only.
• Physical damage or overvoltage voids the warranty.
• Shipping options: FedEx, UPS, DHL.
• Tracking number provided after shipment.

Frequently Asked Questions (FAQ)

Q1: How much user memory does the 1756-L1 have?

The Allen-Bradley 1756-L1 has 64 KB of user memory. This is an early ControlLogix 5550 processor. For larger memory needs, consider 1756-L6x series processors.

Q2: What networks does this processor support?

This processor supports DeviceNet, ControlNet, and DH+ networks. It also supports EtherNet/IP and RS-232-C (DF1/DH-485). Communication requires appropriate interface modules in the chassis.

Q3: Does the 1756-L1 have nonvolatile memory?

No, this processor does not have built-in nonvolatile memory. You need a separate memory module for program storage. Use 1756-M1, 1756-M2, or 1756-M3 modules only.

Q4: What battery works with the 1756-L1?

Use 1756-BA1 or 1756-BA2 lithium battery. Battery weight is 0.59g. Replace battery when LOW BAT LED lights. Do not use other battery types.

Q5: What programming cable do I need for the 1756-L1?

Use 1756-CP3 or 1747-CP3 category 3 serial cable. Connect from your computer's serial port to the controller's RS232 port. Configure RSLinx driver for DF1 protocol.

Buying Guide

When you buy a Allen-Bradley 1756-L1 processor, follow these tips. First, check your memory requirement. This processor has 64 KB only. Second, consider your I/O count. This processor supports 128,000 digital I/O. Third, verify your network needs. Add communication modules for your network type. Fourth, order a nonvolatile memory module. Choose 1756-M1, M2, or M3. Fifth, order a programming cable. Use 1756-CP3 or 1747-CP3. Sixth, order spare batteries. Use 1756-BA1 or 1756-BA2. Seventh, check your chassis compatibility. Use any ControlLogix 1756 chassis. Eighth, verify your software version. RSLogix 5000 required. Ninth, review warranty terms. We offer 12 months coverage. Tenth, choose your shipping method. We use FedEx, UPS, and DHL. Finally, test the processor in a non-production chassis before deployment.

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