Rockwell Automation 1772-LS_LSP,D17726.8.6 PROG/OPER MANUAL-MINI PLC-2/05 User Manual

Page 161

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Block Transfer

Chapter 14

14-6

The boundary word data bits can be set to zero manually using bit
manipulation. Use [SEARCH] 53 and insert zeros. A Get/Put transfer can
be programmed assigning Get and Put instructions to the address
immediately following the last block transfer data address (Figure 14.4).
The value of the Get instruction is set to 000 when programmed.

Figure 14.4

Defining the Data Address Area

1

0

0

030

031

032

PUT

032

000

032

000

10663-I

1

0

1

0

0

0

Data Table

First word in accumulated area of

data table

Last consecutive data address

contains zeros to separate block

transfer addresses from timer,

counter and storage addresses

G

Module Address

The module address is stored in BCD by r = rack, g = module group and
s = slot number. When a block transfer is performed, the processor
searches the timer/counter accumulated area of the data table for a match
of the module address.

Block Length

The block length is the number of words that the module will transfer. It
depends on the type of module and the number of channels connected to it.
The number of words requested by the instruction must be a valid number
for the module: i.e. from 1 up to the maximum of 64. The maximum
number is dependent on the type of module that is performing block
transfer. The block length can also be set at the default value of the
module, useful when programming bidirectional block transfers. For some
modules, the default value allows the module to decide the number of
words to be transferred. See the documentation for the module for for
additional information.

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