1794-TB32 Wiring Diagram: A Comprehensive Guide

As an automation system integrator, you may be familiar with the Allen Bradley 1794-TB32 Terminal Base. This component is responsible for connecting input and output modules to the system, making it an essential part of any automation project. However, understanding its wiring diagram can be challenging, especially for beginners. In this article, we will provide a comprehensive guide to the 1794-TB32 wiring diagram, including step-by-step instructions, tables, and FAQs to help you achieve a successful wiring job.

Understanding the 1794-TB32 Terminal Base

The 1794-TB32 is a seven-segment terminal base module that can accommodate up to 32 I/O points. It consists of seven segments, each having four I/O points. Each segment has a different color to facilitate identification, and the numbers for each I/O point are visible on the front of the module. The terminal base connects to input and output modules through a ribbon cable, and the wiring process follows a specific sequence to ensure proper functionality.

Step 1: Prepare the Input and Output Modules

Before wiring the terminal base, you need to prepare the input and output modules that will be connected to it. Start by determining the number of I/O points required for your application and selecting the appropriate modules. Follow the manufacturer’s instructions for wiring the modules and configuring the settings, such as addressing and data format.

Once the modules are ready, you need to install them onto the terminal base. To do so, slide the module onto the corresponding segment of the base, aligning the guide pins and pressing firmly until you hear a click. Repeat this process for all the modules until they are all securely attached to the base.

Step 2: Wire the Terminal Base

After installing the input and output modules, you can start wiring the terminal base according to the following sequence:

Segment Color I/O Points Wire Color Terminal
Black 1-4 White 1
White 5-8 Blue 2
Red 9-12 Red 3
Green 13-16 Green 4
Yellow 17-20 Yellow 5
Blue 21-24 Black 6
Brown 25-28 Brown 7

Each I/O point corresponds to a terminal on the base, labeled from 1 to 32. As shown in the table above, the wiring process starts with the black segment, which connects to terminals 1-4. You need to connect a white wire to terminal 1, a blue wire to terminal 2, a red wire to terminal 3, and a green wire to terminal 4. Follow this pattern for the rest of the segments, using the corresponding wire colors and terminals.

Step 3: Test the Wiring

After wiring the terminal base, you need to test its functionality to ensure that all the input and output modules are working correctly. Follow the manufacturer’s instructions for testing and troubleshooting the system, such as using a multimeter to check the voltage and resistance of the circuits.

FAQs: Frequently Asked Questions

What is the maximum number of I/O points that the 1794-TB32 can accommodate?

The 1794-TB32 can accommodate up to 32 I/O points, divided into seven segments. Each segment has four I/O points, except for the last segment, which has only two points.

Can I use different wire colors for the terminals?

While it is recommended to use the manufacturer’s specified wire colors for the terminals, you can use different colors as long as you follow the wiring sequence and ensure that the connections are secure and correctly labeled.

What do I do if a module is not working after wiring the terminal base?

If a module is not working after wiring the terminal base, you need to troubleshoot the system and check for any loose connections, incorrect addressing or settings, or faulty components. Follow the manufacturer’s instructions for testing and replacing the modules as needed.

Are there any safety precautions I should take when wiring the terminal base?

Yes, you should always follow the manufacturer’s safety instructions when working with any electrical components. This may include wearing protective gear, such as gloves and safety glasses, and turning off the power supply before wiring or testing the circuit.


The 1794-TB32 Terminal Base is an essential component of any automation system, and understanding its wiring diagram is crucial for achieving a successful project. By following the step-by-step instructions and tables provided in this article, you can confidently wire the terminal base and test its functionality, ensuring that all the input and output modules are working correctly. If you have any further questions or concerns, refer to the FAQs section or consult the manufacturer’s technical support.