Overview
The Allen-Bradley 1746-A2 is an SLC 500 expansion chassis designed to extend I/O capacity in fixed industrial automation systems. This 2-slot expansion rack provides flexibility in an SLC 500 system configuration, allowing technicians and integrators to add communication modules, specialty cards, or additional I/O without modifying the main controller rack. The 1746-A2 belongs to the Allen-Bradley SLC 500 series and offers two additional module slots to extend the functionality of an existing controller system.
Key Features
- 2-Slot Expansion Capacity: allows installation of two additional SLC 500 modules to extend system functionality
- Back-Panel Mounting: designed for secure and straightforward integration into existing control panels
- Requires its own separate power supply fitted on the left-hand side of the chassis
- Modular design compatible with specific SLC 500 I/O and communication modules
- Industrial-grade durability for harsh automation environments
Technical Specifications
- Backplane current: up to 10 A at 5.1 Volts DC and 2.88 A at 24 Volts DC
- Dimensions: approximately 6 x 6 x 3 inches; Weight: approximately 2 lb
- Operating temperature range: 0-60 degrees Celsius (32-140 degrees Fahrenheit) in a relative humidity of 5-95% non-condensing
- Back-Panel mounting with open enclosure
- Requires separate external power supply
Typical Applications
- Expanding fixed I/O SLC 500 systems with additional module slots
- Adding communication modules (Ethernet, PROFIBUS, DeviceNet) to legacy systems
- Integrating specialty modules such as thermocouple or analog input/output cards
- Upgrading automation systems without replacing the main controller
- Panel-mounted distributed control in manufacturing and process industries
Compatibility & Replacements
Compatible With
- 1747 SLC processor, 1746 SLC I/O adapter module, and 1746 I/O modules
- SLC 500 series processors (1747-L, 1747-M, etc.)
- SLC 500 fixed I/O systems requiring expansion
- Chassis interconnection cables for interconnecting up to 3 chassis for a maximum of 30 module slots
Replaces / Drop-In Replacement For
- Alternate Part Numbers: 1746-A2/A, 1746-A2 Series A
- Previous SLC 500 2-slot expansion configurations
Works With
- Allen-Bradley RSLogix 500 programming software
- SLC 500 I/O and communication modules
- Standard industrial automation protocols (EtherNet/IP, DeviceNet, PROFIBUS)
- Back-panel DIN rail and panel-mount installation
















