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Rockwell Automation 1785-KA5P/B DHP COMM. ADAPATER MOD. User Manual

Page 37

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Communicating through the 1785ĆKA5

Communication Adapter Module

Chapter 3

3-9

The following information applies to this transaction:

The command must be a PLC-2-type command.

The message is a remote message because the destination is not on the

local link.

The remote station is the octal equivalent of the decimal address of the

destination (for example, SLC 5/02 address = 10 decimal = 12 octal.)

In the message instruction, set the LINK_ID to zero (0) even though the

actual LINK_ID does not equal zero.

The local node is the DH+ station address of the 1785-KA5.

File 9 must exist in the SLC 5/02.

Important: File 9 must contain a minimum of 17 elements. The PLC-5
begins writing into element 16 because the destination table address
contains a minimum of 10 elements.

The destination data table address specifies the data word number to be

accessed within file 9. The PLC-5 automatically converts this address to
a byte address by doubling the decimal equivalent of the word address.

For example: 010

8

= 16

10

and 177

8

= 254

10

.

SLC 500 processors use two types of addressing:

word addressing
byte addressing

To

Use this type

access only even

words

word addressing. SLC 500, 5/01, and 5/02 processors use

word addressing. Therefore, you can address only even

addresses in file 9 between word 16

10

and word 254

10.

access both even and

odd words

byte addressing. The SLC 5/02, series C, FRN 3 or later can

use byte addressing when bit S:2/8 is set. Therefore, you can

address both even and odd addresses between word 8

10

and

word 255

10

in file 9.

If the SLC 5/02 is in word addressing mode, the destination

data table address, when doubled and converted to decimal,

represents the word number to be accessed.
If the SLC 5/02 is in byte addressing mode, the destination

data table address, when converted to decimal, represents the

word number to be accessed (see Table 3.A.)

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