Allen-Bradley 1790-T8A0X CompactBlock LDX I/O Digital Input Module

Product Introduction

When you need reliable I/O expansion for industrial automation, the Allen-Bradley 1790-T8A0X CompactBlock LDX I/O digital expansion module delivers a cost-effective solution. This module integrates seamlessly with DeviceNet networks and offers 8 non-isolated inputs for monitoring AC signals. Its compact design fits tight panel spaces, making it ideal for low-cost applications. The 1790-T8A0X works with Allen-Bradley PLC, SLC, Logix, or SoftLogix controllers via DeviceNet scanner modules.

Technical Specifications Breakdown

The 1790-T8A0X operates with an on-state voltage range of 85 to 132 Volts AC, with a nominal 110 Volts AC input. Maximum on-state current is 9 milliamps at 132 Volts AC, and off-state voltage is 45 Volts AC maximum. Input impedance is 18 kΩ. Signal delay times are 10 milliseconds off to on and 30 milliseconds on to off. The module requires an external 110 Volts AC power supply and dissipates up to 3 Watts at 132 Volts AC. Isolation between I/O and logic uses photocoupler isolation rated at 1250 Volts AC. The module uses fixed screw-type terminations with a screw torque of 7 lb-in maximum, using copper or copper-clad aluminum conductors. Recommended fusing is 1 Amp, 250 Volts, normal blow.

Industry Applications

This module excels in discrete manufacturing lines where monitoring AC inputs from sensors, push buttons, or limit switches is required. For example, in a packaging line, the 1790-T8A0X can capture status signals from multiple machines, feeding data to a central controller via DeviceNet. Its 8 non-isolated inputs reduce wiring complexity, and the NEMA Type 1 enclosure protects against dust and light moisture. Another application is in material handling systems where compact I/O blocks fit into tight control cabinets.

Installation & Setup Guidance

Mount the 1790-T8A0X in a NEMA Type 1 rated enclosure. Use copper or copper-clad aluminum conductors for wiring. Tighten terminal screws to 7 lb-in maximum. Connect the external 110 Volts AC power supply to power the inputs. For DeviceNet communication, supply 24 Volts DC nominal (range 11…28.8 Volts DC) to the base module. Configure the module using rotary switches or embedded ESD files. Ensure the AC line fuse is a 1 Amp, 250 Volt normal blow type.

Compatibility & Integration

The 1790-T8A0X communicates via DeviceNet, a robust device-level network. It is compatible with Allen-Bradley PLC, SLC, Logix, and SoftLogix controllers through DeviceNet scanner modules. The module can expand I/O for both digital and analog base modules. Its 8 LED indicators show network and module status for easy diagnostics.

Selection Guide & Purchasing Advice

Before purchasing, verify your system's DeviceNet compatibility and power supply requirements. The 1790-T8A0X requires an external 110 Volts AC supply for inputs and a 24 Volts DC supply for DeviceNet power. Confirm the enclosure meets NEMA Type 1 standards. For complete technical specifications, please contact BluePLC Industrial. BluePLC Industrial offers genuine Allen-Bradley modules with expert support to ensure the right fit for your application.