Rockwell Automation 1771-IFF/A,D17716.5.116 FAST ANALOG INPUT MODULE User Manual

Page 83

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D–3

Block Transfer (Mini-PLC-2 and PLC-2/20 Processors)

Publication 1771Ć6.5.116 - July 1996

The input module transfers a specific number of words in one block
length. The number of words transferred is determined by the block
length entered in the output image table control byte corresponding
to the module’s address.

The bits in the output image table control byte (bits 00 - 05) must be
programmed to specify a binary value equal to the number of words
to be transferred.

For example, Figure D.2 shows if your input module is set up to
transfer 6 words, you would set bits 01 and 02 of the lower image
table control byte. The binary equivalent of 6 words is 000110. You
would also set bit 07 when programming the module for block
transfer read operations. Bit 06 is used when block transfer write
operations are required.

Figure D.2

SettingBlock Length (Multiple GET Instructions only)

1 0 0 0 0 1 1 0

Data Address

Contains Module

Address in BCD

Output Image Table Control

Byte Contains Read

Enable Bit andBlock

Length in Binary Code

010

012

017

027
030

1

2

0

Data Table

1
R

Control

Byte

Read6 Words

from Module

Block Transfer

ReadEnable Bit

For Block

Transfer Active

Operations Only

Output Image Table

12172

Number of

Words to

T

f

Binary Bit Pattern

Lower Output Image Table Byte

Transfer

05

04

03

02

01

00

Default

0

0

0

0

0

0

1

0

0

0

0

0

1

2

0

0

0

0

1

0

3

0

0

0

0

1

1

4

0

0

0

1

0

0

5

0

0

0

1

0

1

6

0

0

0

1

1

0

:

:

18

0

1

0

0

1

0

19

0

1

0

0

1

1

Settingthe Block Length

(Multiple GET Instructions

only)

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