Bradley Smoker PLC-5 user manual Choosing an Addressing Mode

Addressing I/O and Controller Memory 4-3

Choosing an Addressing Mode

2-slot addressing

For each I/O chassis in your system, you must define how many I/O chassis slots make up an I/O group (1 word each in the input image table and output image table); this choice is the chassis’ addressing mode. Choose from among these available modes:

2 I/O chassis slots = 1 I/O group = 1 input image word and 1 output image word = 16 input bits and 16 output bits.

16 bits input 16 bits output

1-slot addressing

1 I/O chassis slot = 1 I/O group = 1 input image word and 1 output image word = 16 input bits and 16 output bits.

16 bits input and 16 bits output

1/2-slot addressing

1/2 of an I/O chassis slot = 1 I/O group = 1 input image word and 1 output image word = 16 input bits and 16 output bits.

Controller memory

Rack x

Output Image Table

Word #

x

x

x

x

x

x

x

x

Input Image Table

Word #

x

x

x

x

x

x

x

x

16 bits input and 16 bits output

When you place your I/O modules in the I/O chassis slots, the module’s density determines how quickly I/O groups form. For example, let’s choose

1-slot addressing and see how 8-, 16-, and 32-point I/O modules fill controller memory.

Publication 1785-UM012D-EN-P - July 2005