The Allen-Bradley 1756-IB16 is ControlLogix I/O module. This 16-point DC input module, with 8 points per group, can be connected to a 1756 ControlLogix chassis. The compatible removable terminal block housings, or RTB, are the 1756-TBNH 20 positions NEMA RTB and the 1756-TBSH 20 position spring clamp RTB. Note that before installation, users should have the compatible RTB on hand and that the 1756 chassis and power supply should be installed and grounded.

The nominal input voltage of the 1756-IB16 module is 24 Volts DC, while the voltage category is 12/24 Volt DC sink. Its operating voltage range is 10 to 31.2 Volts DC and the total backplane power is 0.56W. The current draw at 5.1 Volts DC is 100 mA. At 24 Volts, the current draw is 2 mA. This module also has a maximum inrush current of 250 mA peak, which decays to 37% in 22 milliseconds, without activation. Its isolation voltage is 250 Volts continuous. The power dissipation of this module is around is 5.1 Watts at 60 Degrees Celsius and the thermal dissipation is 17.39 BTU/hour. The on-state current of this module ranges from 2.0 mA at 10 Volts DC to 10 mA at 31.2 Volts DC. At an off-state, it has a maximum voltage of 5V and a maximum current of 1.5 mA. The module's input delay time has a maximum of 1 ms hardware delay plus the user-configurable filter time (0, 1, or 2 milliseconds). It has a maximum hardware delay time of 2 milliseconds plus the user-configurable filter time (0, 1, 2, 9, or 18 milliseconds).

The Allen-Bradley 1756-IB16 is a DC sinking input module that operates at a nominal input voltage of 24VDC. This module is used with 24VDCinput signals however, may still be used with AC input voltages provided that an appropriate interposing circuitry or component is installed.

This module supports single-rack, stand-alone controller configuration for smaller and less critical application. It may also be used in larger applications where a higher degree of criticality is involved such a Remote I/O system or a Distributed Control System (DCS).

This module may be used as Discrete Input module of any ControlLogix configuration even, PlantPaX DCS platform of Allen-Bradley. There is virtually no limit with the number of installations of this module. The number of instances or installation depends on the Processor’s memory capability and the Physical chassis used or available slot.



The 1756-IB16 uses a Removable Terminal lock that provides a modular way of terminating input signals. It may be replaced with RTB part number of 1756-TBNH 1756-TBSH. It has a change of state property that is user-configurable and useful in applications that require immediate action when a certain input signal has changed to the defined state. Change of State (COS) bypasses the normal scan cycle of the processor for a faster logic execution.