Rockwell Automation 1747-PTxx Getting Started Guide for HHT - Manual (Page 27)

Chapter 3
Creating a Program
3–2
Controller Styles
As previously mentioned, SLC 500 controllers are available in two styles —
the fixed controller and the modular controller. Examples are shown in the
figure below.
SLC 500 Modular Controller SLC 500 Fixed Controller
7–slot rack
Slot 0 1 2 3 4 5 6
Processor & Power Supply Expansion Rack
1 2 Slot 0
Processor
Power Supply
The fixed controller combines a power supply, processor (CPU), and a fixed
number of I/O points in a single unit. You have the option of adding a 2–slot
expansion rack if you want to add I/O points.
The modular controller consists of a power supply, 1–3 I/O racks, a processor
module that you insert in slot 0 of the first rack, and various I/O modules that
you insert in the remaining slots of the racks.
Slot Numbers: Note that slot numbers are indicated in the figure above. In
fixed controllers, slot 0 applies to the processor and fixed I/O points; slots 1
and 2 apply to I/O modules located in the expansion rack. In modular
controllers, slot 0 is always reserved for your processor module; the
remaining slots apply to the various I/O modules you have inserted.
Catalog Numbers
When you configure your controller, you must specify the processor catalog
number, rack catalog numbers, and I/O module catalog numbers as required.
The location of the catalog number on the various components is shown in
the following figures.
Make a record of controller components: We recommend that you make a
list of the processor, rack, and I/O catalog numbers, and also the rack
numbers assigned to the racks and the slot locations of all I/O modules. You
can then refer to this list as you configure your controller.