PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1771-CFM is a PLC-5 configurable flowmeter module designed for frequency and pulse calculation. It interfaces directly between the PLC-5 chassis and field devices such as turbine flowmeters or magnetic pickups. The module can also calculate shaft speed and process signals from any standard TTL pulse source. It offloads high-speed pulse calculations from the main processor to preserve controller memory.
This module provides four input channels and four output channels. The maximum input frequency reaches 100 kHz with a processing scan time between 1.3 and 5.5 milliseconds. Operating temperatures range from 0 to 60 degrees Celsius. Power dissipation ranges between 2 and 13 Watts, with a maximum backplane current draw of 1.0 Amp.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
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| Backplane Current | 1.0 Amps max |
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| Category | PLCs |
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| Coating | Conformal Coat |
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| Module Scan Time | 1.3-5 ms |
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| Module Type | Specialized I/O Module |
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| Number of Inputs | 4 Digital: Magnetic Pickup 50 mV-200 V AC Peak, TTL-Compatible 4-40 V DC, Proximity Pickups Bently 3300 5 & 8 mm |
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| Number of Outputs | 4 Digital: 5-40 V DC (Supplied by User) |
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| Product Line | PLC 5 |
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| Slots | 1 Slot |
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| Storage Temperature | -40-185 F (-40-85 C) |
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| UPC | 612598126019 |
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| Weight | 1.06 lbs (0.48 kg) |
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| Wiring Arm | 1771-WN |
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TECHNICAL INFORMATION
Features
- Offers four digital input channels supporting magnetic pickups, TTL-compatible signals, and proximity probes.
- Provides four digital output channels rated for user-supplied 5 to 40 V DC operation.
- Supports a maximum input frequency of up to 100 kHz.
- Features a programmable count value range from 0 to 9,999,999.
- Includes four operating modes covering totalizer, frequency measurement, and direction sensing.
- Delivers diagnostic information words directly to the controller configuration block.
TECHNICAL INFORMATION
Applications
- Turbine flowmeter pulse counting in oil, gas, and pipeline transport systems.
- Shaft speed calculation using magnetic pickups or single-channel shaft encoders.
- Flow measurement and totalization in power generation facilities.
- Liquid batching and volume measurement in food and beverage processing.
TECHNICAL INFORMATION
Connections / Interfaces
- Connects to field wiring through a 1771-WN removable wiring arm.
- Accepts magnetic pickup inputs from 50 millivolts to 200 volts AC peak.
- Supports TTL-compatible pulse signals ranging from 4 to 40 volts DC.
- Directly interfaces with Bently Nevada 3300 5 mm and 8 mm proximity sensors.
TECHNICAL INFORMATION
Installation Guidelines
- Installs into a single slot of an Allen-Bradley 1771 I/O chassis.
- Requires a 1771-WN wiring arm for electrical connections to field instrumentation.
- Ensure operating ambient temperature remains between 0 and 60 degrees Celsius.
TECHNICAL INFORMATION
Configuration Guidelines
- Select from four operational modes during setup.
- Modes include non-resettable totalizer, standard totalizer, high-resolution frequency, and direction sensor.
- Direction sensor mode functions across channels 0/1 or channels 2/3.
- Diagnostic data is transmitted to the PLC processor via configuration block words.
TECHNICAL INFORMATION
Compatibility
- Installs in any standard 1771 I/O chassis used with PLC-5 systems.
- Functions as a direct replacement for 1771-QRC and 1771-QRD modules.
- Replacement does not require changes to existing ladder logic programs.
TECHNICAL INFORMATION
Lifecycle / Replacement Information
- Direct replacement for legacy 1771-QRC and 1771-QRD flowmeter modules.
- Preserves existing ladder logic programs when replacing older modules.
TECHNICAL RESOURCES
Documentation
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSInstalls in any standard 1771 I/O chassis used with PLC-5 systems. Functions as a direct replacement for 1771-QRC and 1771-QRD modules. Replacement does not require changes to existing ladder logic programs.
Verify compatibility against the exact Part Number, revision and manufacturer documentation before ordering.
PART VERIFICATION
Before You Order
Industrial automation parts can share similar model names, suffixes and revisions. Confirm the complete manufacturer Part Number before purchase.
01Check Part NumberMatch the complete ordering code on the existing unit.
02Confirm RevisionCheck suffix, hardware or firmware when applicable.
03Send a Label PhotoWe can review a clear label photo when identification is uncertain.
ORDERING PROCESS
From RFQ to Dispatch
1Submit Part Number2Verify Product Identity3Confirm Stock & Condition4Issue Quotation5Dispatch & Tracking
PRODUCT FAQ
Frequently Asked Questions
What is the primary function of the Allen-Bradley 1771-CFM?
The 1771-CFM calculates flow rates and shaft speeds from pulse and frequency inputs.
Which input signals are compatible with the 1771-CFM module?
It supports magnetic pickups, TTL-compatible pulse sources, and Bently Nevada 3300 proximity probes.
Can the 1771-CFM replace legacy 1771-QRC or 1771-QRD modules?
Yes, it directly replaces 1771-QRC and 1771-QRD modules without ladder logic modifications.
What is the market reference price for the 1771-CFM?
Observed market reference pricing is around $189.00 USD for refurbished units. This figure is an indicative market reference only and not a final quotation.
