Rockwell Automation 1785-KA5P/B DHP COMM. ADAPATER MOD. User Manual
Page 37
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.)