Allen-Bradley 1746-A7 SLC 500 Mounting Chassis

Configured for housing SLC processors, power supplies, and operational I/O modules within SLC 500 platforms, the Allen-Bradley 1746-A7 (1746-A7 Mounting Chassis) provides direct physical/electrical execution.

Hardware Specifications

Profinet / EtherNet/IP Deterministic Networks and Base Integration

The Allen-Bradley 1746-A7 establishes the local electrical backbone required to route data links between modules and supervisory network architectures, including Profinet / EtherNet/IP deterministic networks via dedicated scanner modules. The integrated backplane bus utilizes rigid multi-pin connectors to distribute 5.1 VDC and 24 VDC power lines while simultaneously routing deterministic parallel address and data lines. This hardware design maintains transmission timing bounds and structural alignment across all 7 local slots.

Frequently Asked Questions

Q: What are the current loading limitations when engineering a system across the 1746-A7 backplane?

A: The chassis backplane exhibits strict current limits of 10 A maximum at 5.1 VDC and 2.88 A maximum at 24 VDC. The cumulative consumption of the installed processor and peripheral modules must not exceed these values.

Q: Can multiple 1746-A7 chassis assemblies be connected to extend total slot density?

A: Yes. The hardware configuration supports interconnection with up to 2 other chassis assemblies utilizing optional chassis interconnect cables, allowing logical expansion of the physical SLC backplane bus.

Q: Does this mounting chassis support hot-swapping or insertion of I/O cards while powered?

A: No. The SLC 500 architecture requires complete removal of input power before inserting or extracting any module from the 7 slots to avoid backplane bus electrical faults or permanent transceiver component damage.

Field Installation Guidelines

• Enclosure Mounting Orientation: Secure the assembly using the 4 mounting tabs provided. Use Phillips screws with star washers or SEM screws to establish continuous chassis grounding directly to the sub-panel.
• Module Slot Alignment: Slide modules smoothly along the integrated plastic module guides until the top and bottom chassis latches lock. Improper alignment can result in damaged backplane pins.
• Multi-Chassis Cable Routing: When deploying expansion cables to connect separate racks, do not exceed the specified lengths of the official interconnect cables to prevent signal attenuation or propagation delays.
• Thermal Management Clearances: Maintain structural spacing limits above and below the chassis to allow unimpeded convection airflow from the power supply heat sinks, keeping internal temperatures within the 0 deg C to +60 deg C operating range.