1756-N2XT Allen-Bradley Slot Filler Module

Allen-Bradley 1756-N2XT ControlLogix-XT Empty Slot Filler Card

Product Introduction

The 1756-N2XT from Allen‑Bradley is a simple yet essential component for any ControlLogix‑XT chassis. Its main job is to fill unused slots. This action prevents dust buildup and ensures proper airflow inside the enclosure. Many engineers overlook slot fillers, but they play a key role in system reliability.

Additionally, the 1756-N2XT carries basic communication references for RS‑232, RS‑422, and RS‑485. However, please note that it does not actively process data. Instead, it acts as a mechanical placeholder. For instance, you can install it in any empty slot of a 1756 chassis. Therefore, your system maintains a clean and professional appearance.

Furthermore, this module is built for extreme environments. The Allen‑Bradley 1756-N2XT operates between -25°C and 70°C. This makes it ideal for oil and gas, mining, or outdoor automation projects. You get the same rugged design as other XT series components.

Meanwhile, the module draws only 800 mA at 5V and 3 mA at 24V. Its power dissipation is 6.2 Watts. Thermal dissipation equals 21.2 BTU/hour. These low values mean it adds almost no load to your backplane.

Technical Specifications

• Manufacturer: Allen‑Bradley

• Series: ControlLogix

• Module Type: Slot Filler

• Function: Physically covers empty slots

• Communication ports: RS‑232, RS‑422, RS‑485 (reference only)

• Backplane current (5V): 800 mA

• Backplane current (24V): 3 mA

• Power dissipation: 6.2 W

• Thermal dissipation: 21.2 BTU/hour

• Isolation voltage: 50V continuous

• SERCOS data rate: 4 or 8 Mbit/s (reference)

• Current draw (5.1V): 1.2 A

• Max current per point: 0.5A at 60°C

• Max current per module: 4A at 60°C

• Fuse type: Mechanical slow blow, 3.15A at 250V AC

• RTB compatibility: 1756‑TBNH, 1756‑TBSH, or IFM

Mechanical & Environmental Ratings

• Operating temperature: -25°C to 70°C

• Enclosure: None (open-style)

• Certifications: GOST_R, ROSTECHNADZOR

• Mounting: Directly into any ControlLogix chassis slot

• Isolation voltage (continuous): 265V

Installation Guide

First, ensure your ControlLogix‑XT chassis is powered off. Next, remove the protective cover from an empty slot. Then, align the 1756-N2XT with the slot guides. Push it firmly until the locking mechanism clicks.

For field wiring, use an RTB like the 1756‑TBNH or 1756‑TBSH. Alternatively, connect an Interface Module (IFM). The Allen‑Bradley 1756-N2XT does not require any software configuration. Simply install it and close the chassis.

Finally, power up the system. No LED indicators or programming steps are needed. The module works silently in the background.

Packaging List

• 1 x 1756-N2XT slot filler module

• 1 x quick reference guide (paper)

• No certificate or warranty documents included

Shipping Methods

We ship worldwide using Fedex, UPS, or DHL. Tracking number provided within 24 hours.

Frequently Asked Questions (FAQ)

1. Does the 1756-N2XT communicate with the processor?
No. It only references RS‑232/422/485 signals but does not actively communicate. Its primary function is to fill empty slots.

2. Can I use this module in a standard ControlLogix chassis?
Yes. The 1756-N2XT works in both standard and XT versions. However, it is specifically designed for XT environmental ratings.

3. Do I need to set any switches or parameters?
No. There are no dip switches or software settings. Just install the Allen‑Bradley 1756-N2XT and close the slot.

4. Will this affect my backplane power budget?
Very little. It draws only 800 mA at 5V and 3 mA at 24V. Most systems easily handle this load.

5. How do I clean the 1756-N2XT if dust accumulates?
Use compressed air or a soft dry cloth. Do not use liquid cleaners. Always power off the chassis first.