Allen-Bradley 1756-A10/B ControlLogix Chassis

The Allen-Bradley 1756-A10/B, also cataloged as the 1756-A10/B ControlLogix chassis, serves as the primary ControlLogix backplane chassis utilized to execute high-speed module interconnection and distributed power routing across ControlLogix I/O and processor platforms. Configured for modular back-panel mounting in 10-slot architectures, the 1756-A10/B provides direct electrical backplane coupling between installed ControlLogix modules within a horizontally oriented chassis system.

Within Allen-Bradley ControlLogix architectures, the chassis implements deterministic backplane distribution for 1.2 VDC, 3.3 VDC, 5.1 VDC, and 24 VDC rails, enabling synchronized module communication and power segmentation across installed I/O, CPU, and communication cards.

Hardware Specifications

ControlLogix Backplane Power Distribution and Deterministic Communication

Within the ControlLogix backplane architecture, the 1756-A10/B chassis provides a shared electrical and logical bus structure supporting synchronized module communication across all installed slots. Backplane rails at 1.2 VDC and 3.3 VDC handle internal ASIC and logic domains, while the 5.1 VDC and 24 VDC rails support I/O and communication module subsystems. The deterministic backplane timing ensures aligned data exchange between processor, I/O, and communication modules under cyclic scan execution.

Frequently Asked Questions (FAQ)

Q: Can ControlLogix modules be inserted or removed while the 1756-A10/B chassis is energized?
A: Yes, ControlLogix architecture supports hot-swap insertion. However, module-specific power sequencing must be observed to prevent backplane transient disturbances.

Q: Is backplane current shared across all slots or limited per slot?
A: The chassis provides both chassis-level and slot-level current limits. For example, 5.1 VDC supports 15 A chassis total with 6 A maximum per slot depending on installed module configuration.

Q: Does the chassis provide electrical isolation between slots?
A: No. Electrical isolation is implemented at module level. The chassis itself functions as a shared backplane distribution structure.

Field Installation Guidelines

• Install chassis in horizontal orientation only as specified by mechanical design constraints

• Ensure 8 AWG functional earth connection and 14 AWG protective earth bonding before energizing system

• Maintain minimum cabinet clearance for airflow around open-style chassis assembly

• Verify backplane connector alignment prior to module insertion to avoid pin damage

• Distribute high-current modules across slots to avoid localized backplane rail loading

• Ensure cabinet grounding integrity to reduce noise coupling into backplane communication lines