Data encoding and addressing chapter 6 – Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual User Manual

Page 149

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Data Encoding and Addressing

Chapter 6

6-12

To send a command message to a PLC-5 station, you put the extended
address of the station in the field labeled “PLC-5 SYSTEM ADDRESS”
in the message block formats of your program. There are two types of
logical addressing:

Logical Binary Addressing
Logical ASCII Addressing

Figure 6.8 shows the logical binary address you use to access the 360th
element in Integer File 10.

Figure 6.9 shows the logical ASCII address to access the 360th element in
Integer File 10.

Figure 6.8
PLC-5 Logical Binary Addressing

Level 1
Level 2
Level 3
Level 4

0

360

0

10 .

0

0

0

0

1

1

1

1

0

0

0

0

0

0

0

0

0

0

0

0

1

0

1

0

1

1

1

1

1

1

1

1

0

1

1

0

1

0

0

0

Byte 1

Byte 2

Byte 3

Byte 4
Byte 5

Byte 1

Is the flag byte. In this case it indicates that the addresses for all levels are
specified in the bytes that follow.

Byte 2

Is the value for the Level 1 address (0 for Data Table).

Byte 5

Is the low byte of Level 3 address.

Byte 3

Is the value for the Level 2 address.

Byte 4

Is a delimiter that says the next two bytes are one address.

Byte 6

Byte

Is the high byte of Level 3 address. Note that Bytes 4 and 5 together give a
value of 360.

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

Byte 6
Byte 7

Binary

Hex

0 F

0 0

0 A

F F

6 8

0 1

0 0

Byte 7

Is the value for the Level 4 address.

= Data Table Area
=
=
=

File
Element
Subelement

.

.

14691

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