ALLEN BRADLEY 1756-IB16I/A ControlLogix Isolated DC Input Module

OverviewALLEN BRADLEY 1756-IB16I/A is a 16-point individually isolated DC discrete input module for Rockwell ControlLogix platform, revision A. ALLEN BRADLEY 1756-IB16I/A accepts 10–30VDC field signals, rated for nominal 24VDC, with 250V continuous isolation between each input channel. It is installed in a standard 1756 ControlLogix chassis and communicates with the Logix controller via the backplane bus. Channel-to-channel isolation eliminates ground loops and suppresses electrical noise, suitable for harsh industrial sites with different ground potentials. It supports configurable input filter time and Change of State (COS) event notification, which improves signal response efficiency. The module uses 36-pin removable terminal block for field wiring, supporting quick hot-swap replacement. It is widely used for limit switches, proximity sensors, auxiliary contacts and emergency signal collection. ALLEN BRADLEY 1756-IB16I/A remains active in production and is a common spare for ControlLogix I/O system maintenance and expansion.

FeaturesALLEN BRADLEY 1756-IB16I/A provides independent isolation for each of the 16 channels, separating field circuits from the control backplane. The ControlLogix Isolated DC Input Module supports user-defined input filtering to filter out transient noise and contact bounce. Each channel has an on-board status LED for direct visual diagnosis. It works with local chassis or remote I/O racks over EtherNet/IP, ControlNet. It is configured and diagnosed through Studio 5000 / RSLogix 5000 software. It carries CE, UL/cUL certifications and meets industrial EMC and shock-vibration standards. ALLEN BRADLEY 1756-IB16I/A can be mixed with other standard and isolated I/O modules to build flexible discrete signal acquisition systems.

SpecsALLEN BRADLEY 1756-IB16I/A isolated DC input module. The ControlLogix Isolated DC Input Module catalog: 1756-IB16I, revision A. Input channels: 16 points, individually isolated. Input range: 10–30VDC, nominal 24VDC. Isolation rating: 250V continuous between channels. Terminal: 36-pin removable terminal block. Communication: ControlLogix backplane. Configuration: input filter, COS event trigger. Mounting: 1756 chassis slot. Lifecycle: active. It is stocked as isolated discrete input spare.

Operating ParametersALLEN BRADLEY 1756-IB16I/A ambient operating temperature: 0℃ ~ +60℃. The ControlLogix Isolated DC Input Module relative humidity: 5%~95% non-condensing. Power supply: 5.1V DC from chassis backplane. Max power dissipation: approx 5W. Protection class: IP20. EMC: comply with IEC industrial standards.

PrincipleALLEN BRADLEY 1756-IB16I/A receives 24VDC discrete signals from field sensors and switches. The ControlLogix Isolated DC Input Module isolates each channel through optocoupler isolation circuits, converts field on/off status into digital logic signals, then transmits data to the Logix controller over the backplane. Built-in filter circuit suppresses spike noise and contact bounce. When COS function is enabled, the module sends status change messages immediately instead of waiting for the regular RPI cycle. If channel overvoltage or optocoupler damage occurs, ALLEN BRADLEY 1756-IB16I/A will fail to read the corresponding field signal.

ApplicationsALLEN BRADLEY 1756-IB16I/A is widely deployed in automotive production lines, packaging machines, water treatment, oil & gas skids, power auxiliary control and material handling systems. The ControlLogix Isolated DC Input Module undertakes signal acquisition for limit switches, proximity switches, relay auxiliary contacts, safety door switches and emergency stop feedback. It cooperates with ControlLogix CPU and output modules to build stable discrete control systems. ALLEN BRADLEY 1756-IB16I/A is a preferred spare for isolated signal acquisition in noisy industrial environments.