Allen-Bradley 1771-CFM Flowmeter/Counter Module

The Allen-Bradley 1771-CFM Configurable Flowmeter Module is a PLC-5 I/O card that provides four pulse-counting inputs and four outputs in a single-slot form factor, designed to measure and totalize flow from flowmeters and related devices. It accepts a variety of TTL and pulse-output signals, including magnetic pickups (50 mV–200 V AC peak), TTL-compatible 4–40 V DC inputs, and Bently 3300 proximity devices, enabling direct interfacing to magnetic pickups, single-channel shaft encoders, or turbine flowmeters that generate TTL pulses. The module is configured for use with a PLC-5 processor via the 1771-WN wiring arm and offers scan times in the range of roughly 1.3–5 ms, depending on configuration and input frequency. Its four digital inputs feed into four digital outputs, which are rated for 5–40 V DC (supplied by the user), supporting straightforward flow-totalization logic, signaling, and gating. This configurable flowmeter solution is intended for industrial automation tasks that require high-frequency pulse counting to derive flow rate or totalized flow, making it a compact, single-slot option for PLC-5 racks.