Allen-Bradley ControlLogix 1756-IF4FXOF2F 4-Input 2-Output Fast Analog Combo Module

Product Description

The 1756-IF4FXOF2F is a specialized high-speed combination module for the ControlLogix platform, consolidating four high-speed analog inputs and two high-speed analog outputs into a single slot. This "Fast" (F-series) module is engineered for applications requiring rapid signal sampling and immediate output response, such as turbine control or high-speed motion synchronization. Unlike standard density modules, the 1756-IF4FXOF2F (Part Number 1756-IF4FXOF2F) utilizes advanced circuitry to minimize signal propagation delay. It provides full bipolar voltage and current support across all channels, allowing for mixed-signal interfacing without the need for additional specialized hardware.

Technical Specifications

• Input Channels: 4 High-Speed Voltage/Current

• Output Channels: 2 High-Speed Voltage/Current

• Signal Ranges: ±10V DC, 0…5V DC, 0…10V DC, and 4…20 mA

• Input Resolution: 16-bit effective (Over 21-bit in some modes, correcting legacy 14-bit data)

• Output Resolution: 13 to 16-bit (Varies by signal range)

• Backplane Power (5.1V DC): 375 mA

• Backplane Power (24V DC): 100 mA

• Scan Time: Sub-millisecond capability (Fast-series performance)

• Module Keying: Electronic, software-configurable

• Operating Temperature: 0°C to 60°C (32°F to 140°F)

• Storage Temperature: -40°C to 85°C (-40°F to 185°F)

• Calibration: Factory calibrated; supports field-side user calibration for high-precision loops

Component Comparison and Usage

The 1756-IF4FXOF2F is the preferred choice for engineers looking to save chassis space while maintaining high performance. Compared to a separate 1756-IF8 and 1756-OF4 setup, this combo module provides a balanced I/O ratio for small-scale control loops. It is particularly effective in PID loops where the input-to-output latency is a critical factor in system stability. For installation, a 36-pin Removable Terminal Block (RTB), such as the 1756-TBNH or 1756-TBSH, is required and must be ordered separately.

FAQ

What is the difference between the "F" and standard analog modules?The "F" designation in 1756-IF4FXOF2F stands for "Fast." These modules use an upgraded Analog-to-Digital converter architecture that provides significantly lower latency and higher sampling rates than standard 1756-IF modules.

Does this module require external 24V DC power?No, the module draws its 24V DC requirement directly from the ControlLogix backplane, though it contributes to the overall power supply loading which should be calculated using the Integrated Architecture Builder (IAB).