Allen-Bradley 1756-TBCH ControlLogix 36-Pin Cage-Clamp Removable Terminal Block

Modular Interfacing and Field Wiring Management

The Allen-Bradley 1756-TBCH serves as a critical 36-pin Removable Terminal Block (RTB) that bridges the gap between field-side sensors and ControlLogix I/O modules. By plugging directly into the front of a 1756 module, this cage-clamp unit actively facilitates organized signal distribution without requiring modifications to the module hardware. Maintenance teams often utilize the RTB to swap faulty modules instantly while keeping the original field wiring intact. This modularity ensures that users can reduce mean time to repair (MTTR) and eliminate the risk of wiring errors during hardware upgrades or troubleshooting.

Advanced Termination and Cage-Clamp Technology

This terminal block employs cage-clamp technology to provide high-vibration resistance and secure electrical contact for industrial environments. The 1756-TBCH actively supports a wide range of wire gauges, accommodating single wires from 0.33 to 2.1 mm² (22–14 AWG) and dual-wire configurations up to 1.3 mm². Unlike traditional screw terminals, the cage-clamp mechanism maintains constant pressure on the conductor, which prevents loosening caused by thermal cycling or mechanical shock. Furthermore, the 36-pin high-density layout allows the module to handle complex I/O configurations, such as isolated or diagnostic digital signals, while maintaining a compact physical footprint.

System Integration and Environmental Resilience

Engineers primarily specify the 1756-TBCH for use in the 1756 Chassis system alongside high-density I/O modules like the 1756-IA16I or 1756-OB16IEF. The unit withstands significant industrial stresses, including operating shocks up to 30g and a temperature range of 0°C to 60°C. Because it uses copper wire rated for 90°C or higher, the terminal block ensures reliable power and signal transmission even under full-load conditions. The RTB also features mechanical keying, which prevents operators from accidentally inserting the terminal block into the wrong module type, thereby protecting the system from potential voltage mismatches.

Key Technical Characteristics

• Manufacturer: Allen-Bradley / Rockwell Automation
• Model Designation: 1756-TBCH
• Terminal Type: Cage-Clamp (Removable)
• Pin Count: 36-Pin
• Compatible Wire Sizes (Single): 0.33 mm² to 2.1 mm² (22–14 AWG)
• Compatible Wire Sizes (Double): 0.33 mm² to 1.3 mm² (22–16 AWG)
• Termination Torque: 0.5 Nm (4.4 lb-in)
• Operating Temperature: 0°C to 60°C (32°F to 140°F)
• Mechanical Shock Resistance: 30g
• Product Origin: USA
• System Family: ControlLogix 1756

Primary Industrial Applications

• Connecting field instrumentation to high-density digital and analog I/O modules.
• Simplification of I/O replacement in continuous process manufacturing.
• Managing diagnostic-level wiring for 1756-IB16D modules.
• Standardizing wiring interfaces across large-scale ControlLogix PLC architectures.