Allen Bradley 1756-CFM ControlLogix Flow Meter Module

The 1756-CFM ControlLogix Configurable Flowmeter by Allen-Bradley is a module located on the ControlLogix Chassis, with a single-slot for interfacing between the LogixController and the external I/O devices. It has 4 inputs (2 flow-meter, and 2 gate inputs) with an IEC-certified current rating between 6 and 30mA at 24V DC and at a maximum input frequency of 100 KHz. It has a flow-meter input voltage ranging between +/- 30V DC with a selectable input threshold of 50mV, 1.3V, and 4V and an impedance of 5kΩ.

Technical specifications for 1756-CFM

ManufacturerRockwell Automation

BrandAllen-Bradley

Part Number/Catalog No.1756-CFM

SeriesControlLogix

Inputs2 Flowmeter Inputs, 2 Gate Inputs

Operation ModeTotalizer Fill and Prover

Backplane Current (5Volts)300 milliamps

Backplane Current (24Volts)6 milliamps

Power Dissipation (Max)6 Watts at 60 Celsius

Removeable Terminal Blocks1756-TBNH, 1756-TBSH

EnclosureOpen

Backplane Current (5 Volts DC)10 amps

Backplane Current (24 Volts DC)2.8 Amps

The 1756-CFM has two current sourcing (IEC 1A, 24V DC) outputs with output ratings of 4.5-5.5V DC for 3-20 mA load per point, and 10-31.2V DC for 40mA to 1A load per point. The output has a surge current of 2A for 50ms re-curing every 2s with an OFF state current leakage of <300μA at 31.2V. Its output switching time is 1ms and with an overload current of 4A it offers short-circuit protection. The 1756-CFM has a backplane current of 300mA at 5.1V DC and 6mA at 24V DC and it has a maximum power dissipation of 6W (20.4 BTU/hr). Its operational temperature ranges between 0 and 60°C (32 and 140°F) at 5-95% non-condensing relative humidity limit and it is built to withstand an operational shock of up to 30G.