The Allen-Bradley 1746-A2 is a 2-slot I/O expansion chassis for the SLC 500 products system. Using this expansion chassis is an efficient way to add a little more customization to your system without taking up too much additional space. The 1746-A2 provides a way to house additional modules for a system. This expansion chassis helps you configure your SLC 500 system to accommodate your specific needs. The 1746-A2 2-slot I/O expansion chassis supports only specific combinations of modules. Make sure to refer to the user manual to determine which I/O, communication, and other module types in the SLC 500 system are compatible within the 2-slot expansion chassis. If you are using a thermocouple module with an SLC I/O or communication module in the chassis, take extra precaution and refer to the manual to check for compatibility. Take note that the 1746-A2 2-slot expansion chassis does not accommodate I/O modules in the first slot, labelled number 0. This slot is reserved specifically for processors. If you are leaving a slot un-occupied in the 1746-A2, a 1746-N2 card slot filler should be put in place to protect the chassis from dust or debris.

The backplane current of the 1746-A2 is 10A at 5.1V DC and 2.88 A at 24V DC. Additionally, the chassis has back-panel mounting.  The 1746-A2 is efficiently designed to help expand SLC 500 systems.  The chassis has approximately the following dimensions: 6 x 6 x 3 inches. The weight of the 1746-A2 is approximately 2 lb. Operating conditions for the chassis should remain in the temperature range of 0-60 degrees Celsius (32-140 degrees Fahrenheit) in a relative humidity of 5-95% non-condensing.