Allen-Bradley 1771-CFM Configurable Flow Meter Module

1771-CFM Allen Bradley PLC 5 Flowmeter I/O Module

Product Introduction

The 1771-CFM from Allen-Bradley is a specialized configurable flow meter module within the PLC 5 family. This module acts as a smart interface between your PLC and field flow devices. Specifically, it accepts signals from turbine flowmeters, magnetic pickups, and single-channel shaft encoders. Additionally, it can process TTL pulse sources for versatile flow calculations. The 1771-CFM simplifies programming and conserves valuable processor memory. It directly replaces older 1771-QRC and 1771-QRD modules without requiring ladder logic changes. Therefore, it offers a seamless upgrade path for existing systems. This module serves critical industries like power generation, oil and gas, automotive, and food processing.

Input and Output Specifications

The 1771-CFM features four dedicated digital input channels. These inputs accept magnetic pickup signals from 50 mV to 200 V AC peak. Moreover, they are TTL-compatible from 4 to 40 V DC. This module also supports Bently 3300 proximity pickups in both 5 mm and 8 mm sizes. For outputs, it provides four digital channels operating at 5 to 40 V DC. Crucially, the output power is supplied externally by the user. This flexible I/O configuration allows the 1771-CFM to control up to four devices based on input values. Furthermore, each channel can be configured independently for different measurement tasks. The module processes input frequencies up to a maximum of 100 kHz. Its programmable count value range extends from 0 to 9,999,999.

Configurable Operating Modes

This flow meter module offers four distinct operating modes for maximum flexibility. First, the non-resettable totalizer mode accumulates flow data continuously without reset. Second, the standard totalizer mode allows for manual or automatic resets. Third, the high-resolution frequency mode is available for channels 0/1 or 2/3. This mode delivers precise frequency measurements for critical applications. Fourth, the direction sensor mode also works on channel pairs 0/1 or 2/3. Consequently, users can tailor the 1771-CFM to their specific flow measurement needs. The module scan time ranges from 1.3 to 5 milliseconds. Its maximum processing time is only 5.5 milliseconds for rapid data handling. Additionally, diagnostic information is sent directly to the PLC processor in a configuration block.

Mechanical and Environmental Ratings

The 1771-CFM occupies a single slot in the PLC 5 chassis. Its compact dimensions are 3.5 x 6.5 x 2.0 inches (89 x 165 x 51 mm). This module draws a maximum backplane current of 1.0 Amp. Power dissipation varies between 2 and 13 Watts depending on configuration. For environmental resilience, it features a conformal coating on its circuit board. This coating protects against moisture, dust, and chemical contaminants. The operating temperature range is 0 to 60°C (32 to 140°F). Storage temperatures can safely span from -40 to 185°F (-40 to 85°C). Besides that, this module requires a compatible wiring arm (part number 1771-WN) for field connections. Its lightweight design weighs only 1.9 lbs (0.9 kg).

Installation and Compatibility Notes

Installing the 1771-CFM is a straightforward procedure. First, ensure the PLC chassis is powered off before insertion. Then, slide the module into any available slot in the 1771 I/O chassis. Secure it firmly by tightening the captive screws. Next, attach the 1771-WN wiring arm to the front of the module. This arm provides convenient termination points for field wiring. After installation, configure the desired operating mode via the configuration block. Importantly, the 1771-CFM is a drop-in replacement for older 1771-QRC and 1771-QRD modules. Existing ladder logic remains compatible without modifications. Therefore, upgrading your system requires minimal downtime. Always follow proper grounding and shielding practices for optimal signal integrity.

Packaging and Logistics

Each 1771-CFM module is carefully packaged to ensure safe delivery. The package includes the following items:

• One Allen-Bradley 1771-CFM configurable flow meter module

• Protective anti-static packaging for electrostatic discharge protection

• Quick reference guide with basic installation steps

All shipments are dispatched through trusted global carriers. We primarily use FedEx, UPS, and DHL for fast, trackable deliveries. Please inspect the module immediately upon receipt for any shipping damage.

Frequently Asked Questions (FAQ)

1. Is the 1771-CFM compatible with the 1771-QRC and 1771-QRD modules?
Yes, the 1771-CFM is a direct replacement for both 1771-QRC and 1771-QRD modules. You do not need to change your existing ladder logic program.

2. What type of magnetic pickups work with this flow meter module?
This module supports Bently 3300 proximity pickups in 5 mm and 8 mm sizes. It also accepts standard magnetic pickups from 50 mV to 200 V AC peak.

3. What is the maximum input frequency for this module?
The 1771-CFM handles input frequencies up to 100 kHz. This range covers most turbine flowmeter and shaft encoder applications.

4. What wiring arm is required for this module?
You need the 1771-WN wiring arm for field connections. This arm is sold separately and must be ordered alongside the module.

5. Which shipping carriers do you use for delivery?
We ship all orders using FedEx, UPS, or DHL. These carriers provide reliable tracking and global coverage for your convenience.