Allen-Bradley 1734-IB8 Overview
The Allen-Bradley 1734-IB8 is a compact digital DC sinking input module from the POINT I/O family. It provides eight discrete input channels in a single unit, making it a space-saving solution for distributed I/O architectures. This module accepts a nominal 24VDC signal and requires a 1734-TB or 1734-TBS wiring base assembly for operation. Engineers often choose it for its straightforward integration with any POINT I/O communication adapter.
Technical Specifications and Performance
Each of the eight inputs supports a sinking configuration with an ON-state voltage range from 10 to 28.8VDC. The input current ranges from 2 to 5mA, with a nominal draw of 4mA at 24VDC. You can adjust the input filter time from 0 to 63 ms in software, alongside a fixed 0.5 ms hardware filter. This flexibility helps you reduce electrical noise effects in industrial environments.
Power consumption is modest, with a POINTBus current draw of 75mA at 5V DC and total power dissipation of 1.6 Watts (5.5 BTU/hr). The module includes eight yellow input status LEDs and one green/red logic-side indicator, giving you quick visual feedback. Its dimensions are 56 x 12 x 75.5 mm, and it weighs approximately 31.8 grams.
Installation and Wiring Considerations
The 1734-IB8 mounts on a 1734-TB or 1734-TBS terminal base, which you can install on a DIN rail. Ensure the keyswitch is set to position 1 to avoid miswiring. Use a torque of 0.8 N-m (7 lb-in) for the terminal base screws. The module has an open-style enclosure rating, so you must place it in a clean, dry, and corrosion-free location.
For best performance, keep the surrounding air temperature between -21 and 55 degrees Celsius. Although the module can be mounted horizontally or vertically, always follow the manufacturer's guidelines for clearance and airflow. An experienced installer should handle the setup to preserve the module's longevity.
Integration with Communication Adapters
You can use the 1734-IB8 with any POINT I/O communication adapter to build a distributed I/O network. Series C versions also work with DeviceNet and ProfiBus adapters, offering additional flexibility. The isolation voltage is rated at 50V continuous, with reinforced insulation tested at 2500V DC for 60 seconds between field-side and system.
When planning your system, verify that your adapter supports the required number of modules and that the POINTBus current remains within limits. The 1734-IB8's low current draw makes it easy to fit into most configurations.
Practical Applications and Value
This module suits applications where you need reliable 24VDC discrete input sensing, such as monitoring limit switches, push buttons, or proximity sensors. Its compact size and low power consumption make it ideal for control panels with limited space. By selecting the Allen-Bradley 1734-IB8, you benefit from a proven design with clear status indication and user-adjustable filtering.
In summary, the 1734-IB8 delivers dependable performance in a small footprint. Its straightforward installation and compatibility with multiple communication adapters simplify system design. For engineers seeking a cost-effective input solution, this module offers a practical choice.