Technical Description: Allen-Bradley 1746-A7
The Allen-Bradley 1746-A7 is a 7-slot modular I/O chassis belonging to the SLC 500™ family. This medium-sized chassis acts as the central assembly point for SLC 500 components, providing the electrical connections and physical support needed for the PLC processor and various I/O modules. The 7-slot configuration is widely popular in medium-complexity automation tasks, offering a balanced ratio of I/O density to cabinet space requirements.
System Architecture and Backplane
The integrated backplane of the 1746-A7 manages the distribution of power from the 1746 series power supply to all installed modules. It supports synchronous communication between the CPU and digital, analog, or specialty modules. The chassis is designed for easy installation on a panel backplate, featuring reinforced mounting holes to withstand the mechanical stresses of industrial environments.
Detailed Specifications
- Total Slots: 7 Slots.
- Architecture: SLC 500 Modular System.
- Mounting Type: Horizontal Panel Mount.
- Vibration Resistance: 5 to 2000 Hz at 2.5g.
- Isolation Voltage: Tested to withstand high-voltage surges per industry standards.
- Power Supply Compatibility: Fits 1746-P1, P2, P3, and P4 supplies.
Installation Benefits
By using the 1746-A7, engineers can build a versatile control system that can handle a mix of discrete and analog signals. The chassis supports «hot-swapping» of some modules (depending on system configuration and safety protocols), though standard practice involves powering down the chassis via the attached power supply. The slot design ensures that modules are correctly aligned with the backplane connectors every time.
| Feature | Details |
| Dimensions | 171 x 282 x 145 mm |
| Storage Temp | -40°C to +85°C |
| Backplane 5V Current | 10 Amps |
Maintenance Insights
The 1746-A7 is a ruggedized component but should be inspected periodically for dust accumulation in unused slots. Using slot covers (1746-N2) for empty positions is recommended to maintain optimal electrical performance and protect the backplane pins from environmental contaminants.
Do you need more references from this brand? Explore our full catalog of Allen-Bradley here.
The 7-slot 1746-A7 chassis provides the necessary backplane for modules such as the 1746-IB16 DC input card.
