Industrial Engineer · phase 1 of 16
Rack / Chassis
Mechanical assembly that holds controller modules and connects them through a backplane.
The Explain card
- Plain English
- The rack is the metal frame the modules plug into. It holds them in a row, fixes their slot numbers and joins them to a shared bus.
- Example
- A seven slot chassis might carry a power supply on the end, a CPU in slot 0, an Ethernet card in slot 1 and I/O cards in the rest.
- Why it matters
- Slot position becomes part of an address, so moving a card moves every tag that points to it. Size the rack for the modules you will add next year, because a full rack means a second one and a new address space.
- Hook
- The rack is the street and the slots are the house numbers.
Where it sits in the deck
Phase 1: PLC Controller Hardware
The box itself, from processor and rack to the modules that plug into it, because nothing else in the deck lands until you know what a PLC physically is.
