The Allen-Bradley 1772-LW, also cataloged as the 1772LW Mini PLC Processor Module, operates as a dedicated hardware component for digital control execution and memory-based program processing within PLC-2/17 controller platforms.

Model Identification & Configuration

The 1772-LW is a Mini PLC 2/17 processor module without an integrated power supply. It contains 7.75K words of SRAM memory and supports up to 512 total I/O points through the PLC-2 system architecture.

Hardware Specifications

PLC Control Architecture Compatibility

The Allen-Bradley 1772-LW operates within the PLC-2 controller family and performs instruction execution, data handling, and I/O scan processing. The processor exchanges data through the PLC backplane structure and manages digital control sequences according to stored SRAM program instructions.

The PLC-2 architecture uses fixed processor and I/O rack communication methods. The 1772-LW does not provide integrated power conversion and requires installation with a compatible PLC system power supply.

For Allen-Bradley legacy control systems, processor replacement requires verification of rack configuration, I/O addressing, and firmware compatibility. The module design follows earlier PLC backplane communication methods rather than modern EtherNet/IP deterministic networks.

Ordering Information

• 1 x Allen-Bradley 1772-LW Mini PLC 2/17 Processor Module
• 1 x Compatible PLC-2 Series processor housing assembly
• 1 x Installed SRAM memory module
• 1 x Product identification label
• 1 x Technical inspection report (if supplied)

Field Installation Guidelines

Rack Installation

• Install the module in the designated PLC-2 processor rack position.
• Confirm mechanical alignment before applying insertion force.
• Verify processor seating within the backplane connector.

Electrical Connection

• Confirm system power supply compatibility before energizing.
• Check backplane connections for contamination or oxidation.
• Tighten terminal screws according to the specified 7-9 lb*in torque range.

Configuration Verification

• Confirm I/O addressing matches the existing PLC-2 program configuration.
• Verify memory content before returning the controller to operation.
• Avoid removing or installing modules while system power is applied unless the rack design specifically permits it.

Frequently Asked Questions

• What controller family does the 1772-LW belong to?

  The 1772-LW is a Mini PLC 2/17 processor module designed for Allen-Bradley PLC-2 series controller systems.

• Does the 1772-LW include a power supply?

  No. The module is supplied without an integrated power supply and requires a compatible PLC system power source.

• What memory type is used in the 1772-LW?

  The processor uses SRAM memory with a capacity of 7.75K words for storing PLC program data.

• How many I/O points can the 1772-LW support?

  The module supports a total I/O capacity of up to 512 points within the PLC-2/17 system configuration.

• Can the 1772-LW be installed in modern ControlLogix racks?

  No. The 1772-LW uses PLC-2 series hardware architecture and is not compatible with ControlLogix platforms.

• What type of applications does the 1772-LW control?

  The processor is designed for digital control applications using 10-32 VDC field devices.

• Does the 1772-LW support Ethernet communication?

  No. The module uses legacy PLC-2 communication structures and does not include Ethernet communication interfaces.

• What should be checked before replacing this processor?

  Verify rack compatibility, I/O addressing, memory configuration, and existing PLC-2 program requirements before installation.