Configured for closing unused module positions in standard ControlLogix chassis, the Allen-Bradley 1756-N2 (1756N2 ControlLogix Empty Slot Cover) provides a physical filler for unoccupied chassis slots. Rockwell Automation identifies it as a slot filler for standard ControlLogix chassis.

Model Identification

The catalog number is 1756-N2. The supplied references 1756N2, 1756-N2/A, and 1756-N2/B are retained as ordering references; no functional suffix relationship is inferred from the supplied data.

Hardware Specifications

Rockwell Automation specifies the 1756-N2 for empty slots in standard ControlLogix chassis. The 1756-N2XT is the corresponding filler for ControlLogix-XT and ControlLogix-ZXT chassis.

ControlLogix Chassis Compatibility

The 1756-N2 is intended for standard ControlLogix chassis. Compatible standard chassis families include the 1756-A4, 1756-A7, 1756-A10, 1756-A13, and 1756-A17 families.

The chassis backplane provides the communication path between installed modules and distributes power to those modules. The 1756-N2 itself is a slot filler and does not constitute an active I/O, controller, or communication module.

Industrial Control Platform Compatibility

The 1756-N2 is a passive mechanical component within the ControlLogix modular chassis architecture. It does not establish EtherNet/IP communication, execute controller firmware, process I/O signals, or consume a configured module power budget as an active electronic module.

Because it has no firmware or communication interface, firmware flash compatibility and network configuration do not apply to the 1756-N2. The relevant compatibility requirement is the physical chassis family and slot configuration.

Ordering Information

• 1 x Allen-Bradley 1756-N2 ControlLogix Empty Slot Cover
• Catalog reference: 1756-N2
• Alternate references supplied: 1756N2, 1756-N2/A, 1756-N2/B
• No controller, I/O module, terminal block, communication adapter, or additional electronic assembly is included unless separately specified.

Field Installation Guidelines

Chassis Selection

• Install the 1756-N2 only in a compatible standard ControlLogix chassis.
• Do not substitute the 1756-N2 for the 1756-N2XT where an XT or ZXT chassis configuration requires the corresponding filler.
• Verify the chassis catalog number before installation.

Mechanical Installation

• Align the filler with the vacant chassis slot.
• Secure the component using the chassis mounting mechanism intended for the slot.
• Confirm that the filler is seated correctly and does not obstruct adjacent module installation.

Electrical Considerations

• The 1756-N2 is not an active I/O or communication device.
• No field signal wiring is connected directly to the filler.
• No firmware download or controller configuration is required for the passive filler itself.
• Maintain normal cabinet grounding, shielding, and wiring practices for the surrounding ControlLogix installation.

Thermal and Service Considerations

• Use the environmental limits specified for the applicable standard ControlLogix chassis.
• Do not use the 1756-N2 as a substitute for an active module.
• Before service work, follow the installed chassis and system documentation for power isolation and module removal procedures.

Frequently Asked Questions

• Does the 1756-N2 require a power connection?

  No. It is a passive slot filler and has no specified power input or active electronic circuitry.

• Does the 1756-N2 communicate over the ControlLogix backplane?

  No. The part does not provide controller, I/O, or communication functions. It physically occupies an unused chassis position.

• Can the 1756-N2 be used in a ControlLogix-XT chassis?

  Rockwell Automation specifies the 1756-N2 for standard chassis. XT and ZXT chassis use the 1756-N2XT slot filler.

• Does the 1756-N2 have firmware?

  No firmware function is applicable to this passive slot filler. Firmware installation and flash compatibility therefore do not apply.

• Does the 1756-N2 process field signals?

  No. It has no field terminals, signal channels, analog circuitry, digital I/O circuitry, or communication interface.

• Does the filler affect chassis backplane communication?

  It does not participate in backplane communication. Active modules continue to use the chassis backplane for inter-module communication and power distribution.

• Is the 1756-N2 an I/O module?

  No. Rockwell Automation classifies it as a slot filler module for empty positions in standard ControlLogix chassis.

• Can an empty ControlLogix slot remain unused instead?

  Rockwell Automation documentation specifies the 1756-N2 as the slot-filler component for empty positions in standard ControlLogix chassis.