1746-A4 rack is mostly used for assembly lines   

Product Manual：

1746-A4 rack, Rockwell SLC500 series 4-slot I/O rack, used to accommodate CPU and IO modules.
1. 4 module slots, can be equipped with CPU and input/output cards
2. SLC500 standard backplane bus, data exchange between modules
3. Compatible with 1746 full series IO modules
4. DIN rail installation, assembly inside control cabinet
5. Backplane is responsible for signal and power transmission
6. Scalable with other racks to achieve multi station architecture
7. Metal shell, sturdy structure and vibration resistance
8. IP20 protection, for use inside cabinets

9. No built-in power supply, requires a power module for power supply
10. Support DH-485 bus communication link
11. Slot buckle, easy module disassembly and assembly
12. Compatible with 1747-L541 and 1747-L553 processors
13. Supports local IO and can also be used as a remote IO dock
14. Industrial wide temperature range, workshop environment available
15. Commonly used in assembly lines and water treatment SLC500 control systems
1746-A4 is suitable for small SLC500 control stations with few points.

Product detailed pictures：

product video

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