4-8Addressing I/O and Controller Memory

Assigning Racks

The number of racks in a chassis depends on the chassis size and the addressing mode:

If Using this

2-slot Addressing,

1-slot Addressing,

1/2-slot Addressing,

Chassis Size

Results In

Results In

Results In

 

4-slot

1/4 rack

1/2 rack

1 rack

 

8-slot

1/2 rack

1 rack

2 racks

 

12-slot

3/4 rack

1-1/2 racks

3 racks

 

16-slot

1 rack

2 racks

4 racks

 

 

 

When assigning rack numbers, use the following guidelines:

TIP

 

 

 

 

 

 

One I/O rack number is eight I/O groups, regardless of the addressing mode that you select.

You can assign from one to four racks in your controller-resident local chassis (128 inputs and 128 outputs) depending on the chassis size and addressing mode. You cannot split a controller-resident local I/O rack over two or more chassis or assign unused controller-resident local I/O groups to remote I/O racks.

The default address of the controller-resident local rack is 0.

You cannot split racks across remote I/O and extended-local I/O links. For example, if an 8-slot extended-local I/O chassis is configured as I/O groups

0-3 of I/O rack 2, an 8-slot remote I/O chassis cannot be configured as I/O groups 4-7 of I/O rack 2. For more information about addressing extended-local I/O, see chapter 8.

When using complementary I/O addressing, treat complementary rack addresses individually when grouping racks; primary rack numbers are separate from complement rack numbers.

If you are not using the autoconfiguration function, group together 1/4-racks and 1/2-racks of each logical rack on the configuration screen of your programming software. Do not intersperse these with other rack numbers. For example, your programming software has a screen with the following information for defining racks:

 

 

Rack

Starting

Rack

Range

Fault

Inhibit

Reset

Retry

 

 

Address

Group

Size

 

 

 

 

 

 

 

1

0

1/4

010-011

 

I

0

0

 

 

1

2

1/4

012-013

 

0

0

0

Group together 1/4 racks

1

4

1/4

014-015

 

0

0

0

2

0

1/4

020-021

 

0

0

0

and 1/2 racks

 

2

2

1/4

022-023

 

0

0

0

 

2

4

1/2

024-027

 

0

0

0

 

 

 

 

 

3

0

1/4

030-031

 

0

0

0

 

 

17

0

FULL

170-177

 

0

0

0

Publication 1785-UM012D-EN-P - July 2005

Page 52
Image 52
Bradley Smoker PLC-5 Assigning Racks, If Using this Slot Addressing Chassis Size Results, Slot Rack Racks 2 racks