1771-CFMK Industrial Automation Module by Allen-Bradley

Product Overview

The Allen-Bradley 1771-CFMK is a configurable flowmeter module engineered for precise rate calculation and high-speed totalizing in demanding industrial environments. As a single-slot I/O module, the 1771-CFMK interfaces seamlessly between field devices and Allen-Bradley PLC processors, supporting the PLC-2, PLC-3, PLC-5, and PLC-5/250 families. This module excels in applications requiring magnetic pickup flowmeters, 4 to 40 Volts DC pulse inputs, and proximity probes, making it a versatile choice for flow and turbine metering.

Key Features & Benefits

• 4 Inputs / 4 Outputs: The 1771-CFMK provides four configurable input channels and four output channels, offering flexible integration for flowmeter and gate input configurations.
• Broad Compatibility: Works with Allen-Bradley PLC-2, PLC-3, PLC-5, and PLC-5/250 processors, ensuring easy integration into existing control systems.
• Multiple Operating Modes: Functions as a CFM module or as a drop-in replacement for QRC and QRD modules, simplifying upgrades and spare parts management.
• Robust Input Handling: Each channel accepts magnetic pickup signals (50 mV to 200 VAC), 4-40 VDC pulses (open collector, TTL compatible), and proximity probe inputs compatible with Bently Nevada 3300 transducer systems.
• Efficient Thermal Design: Peak thermal dissipation of 54.2 BTU/hour (13 Watts) ensures reliable operation within a 0 to 60°C temperature range.

Technical Specifications

Industry Applications

The 1771-CFMK is ideally suited for industries such as automotive, food and beverage, power management, and oil and gas. In flow and turbine metering applications, the module's high-speed totalizing capability ensures accurate measurement of flow rates, while its compatibility with magnetic pickup and proximity probes makes it a reliable choice for rotating equipment monitoring. For example, in a natural gas pipeline, the 1771-CFMK can interface with turbine flowmeters to deliver precise totalization data to a PLC-5 processor, enabling efficient custody transfer calculations.

Installation & Setup

Installing the 1771-CFMK is straightforward. The module occupies a single slot in the chassis and connects directly to the backplane. Ensure that the chassis backplane can supply up to 1 Amp for the module. Before wiring, verify that input signals (magnetic pickup, DC pulse, or proximity probe) match the module's input specifications. Configure each channel as either a flowmeter input or a gate input using the module's configuration switches. Always power down the system before inserting or removing the module to prevent damage.

Maintenance & Reliability

Routine maintenance for the 1771-CFMK is minimal. Periodically inspect the module for dust accumulation and ensure adequate airflow to maintain the operating temperature within 0 to 60°C. Check wiring connections for signs of corrosion or loosening. The module's efficient thermal design (max 13 W dissipation) reduces heat stress, contributing to long-term reliability. By maintaining a clean environment and monitoring input signal integrity, you can maximize the service life of the module.

Compatibility & Integration

The 1771-CFMK is designed for seamless integration with Allen-Bradley PLC-2, PLC-3, PLC-5, and PLC-5/250 processors. It supports block-transfer programming, allowing efficient data exchange between the module and the processor. The module can operate as a CFM module or as a replacement for QRC and QRD modules, providing flexibility in system design and upgrade paths.

Selection & Purchasing Guide

When selecting the 1771-CFMK, confirm your processor compatibility and required input types. Verify that your application requires 4 inputs and 4 outputs. If you are replacing an existing QRC or QRD module, the 1771-CFMK offers a direct upgrade path. For reliable sourcing, consider PLC Source PRO for genuine Allen-Bradley parts and expert support.