The Allen-Bradley 1771-DMC, also cataloged as the 1771-DMC Control Coprocessor Main Module, operates as a dedicated hardware component for auxiliary processing and application data management within PLC-5 controller systems.

Model Identification & Module Configuration

The 1771-DMC is a PLC-5 Control Coprocessor Main Module designed to extend processing capability within Allen-Bradley PLC-5 chassis architectures. The module provides additional memory resources and coprocessor functions while operating alongside the main PLC processor.

Hardware Specifications

PLC-5 Backplane Communication Architecture

The 1771-DMC operates as a PLC-5 chassis module and communicates with the controller system through the 1771 I/O backplane structure. The coprocessor architecture allows additional processing functions to be executed separately from the main PLC processor workload.

The module follows Allen-Bradley PLC-5 system architecture requirements, including chassis addressing, module configuration, and firmware compatibility management. Existing PLC-5 installations require verification of processor revision and system configuration before replacement.

Control Coprocessor Processing Function

The 1771-DMC provides dedicated coprocessor resources for PLC-5 applications requiring additional processing capability. The integrated 256 KB memory capacity supports application-related data handling and coprocessor operations.

The module is configured as part of a PLC-5 control system and does not operate as an independent programmable controller. Proper application configuration is required to coordinate data exchange between the main processor and coprocessor module.

Ordering Information

• 1 x Allen-Bradley 1771-DMC PLC-5 Control Coprocessor Main Module
• 1 x Module identification label
• 1 x Product documentation package

Field Installation Guidelines

Module Installation

• Verify PLC-5 chassis compatibility before installation.
• Remove chassis power before inserting or removing the module.
• Confirm module slot position and addressing configuration.

Electrical and System Checks

• Inspect the backplane connector before installation.
• Ensure the chassis power supply capacity is suitable for installed modules.
• Maintain proper grounding practices to reduce electrical interference.

Configuration Maintenance

• Confirm processor and coprocessor communication settings after installation.
• Verify application program compatibility before transferring data.
• Keep backup copies of PLC-5 project files before hardware replacement.

Frequently Asked Questions

• What system is the 1771-DMC designed for?

  The 1771-DMC is designed for Allen-Bradley PLC-5 controller systems using the 1771 chassis platform.

• What is the primary function of this module?

  The module provides additional coprocessor processing capability and memory resources for PLC-5 applications.

• How much memory does the 1771-DMC provide?

  The module includes 256 KB memory capacity for supported coprocessor functions.

• Can the 1771-DMC operate as a standalone controller?

  No. The module requires integration with a compatible PLC-5 processor system.

• Does the module communicate through the PLC backplane?

  Yes. The module exchanges data through the 1771 chassis backplane communication structure.

• Is firmware compatibility required before installation?

  Yes. Existing PLC-5 processor revision and system configuration should be checked before replacement.

• Can the module be removed while powered?

  Power removal is recommended before module installation or removal to prevent hardware faults.

• What maintenance checks are required after installation?

  Verify module recognition, communication status, and application operation after installation.