Allen Bradley 1756-CFM ControlLogix Configurable Flowmeter Allen-Bradley 1756-CFM ControlLogix Configurable Flowmeter 2 Inputs, 2 Outputs (20-Pin) performs high-speed flowmetering for industrial applications. The 1756-CFM interfaces between a Logix controller and external I/O devices. The 1756-CFM modules mount in a ControlLogix chassis and use a Removable Terminal Block (RTB): 1756-TBNH, 1756-TBSH, or a 1492 Interface Module cable that connects to an IFM to connect all field-side wiring. The 1756CFM module has two assignable outputs, which are designed for applications that require fast response.