Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual - Manual (Page 150)

Data Encoding and Addressing
Chapter 6
6-13
Figure 6.9
PLC-5 Logical ASCII Addressing
Displayed Logical Address Symbol
File-Type Identifier
File Number
Delimiter
Element Number
Byte 1 Is the null character that tells the PLC that an ASCII address is to follow.
Byte 2 Is an ASCII “$.”
Bytes3-9 Are the ASCII address in the PLC-5.
Byte 10
Is a null character that ends the ASCII address specification.
$ 10 : 360 N
ASCII Hex
Byte 1 NUL 0 0
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Byte 8
Byte 9
Byte 10 $
N
1
0
:
3
6
0
NUL 2
4
3
3
3
3
3
3
0 4
E
1
0
A
3
6
0
0
14692
Important: PLC-3 controllers can also accept PLC/PLC-2 type
command messages with the PLC/PLC-2 logical addressing format.
Before sending this type of command to a PLC-3 station, you must first
allocate a PLC-3 input file (the file number is the same as the
PLC/PLC-2’s octal station number) to simulate PLC/PLC-2 memory
(refer to Publication 1775-6.5.1). In addition, PLC-3 controllers can
transmit both PLC-3 and PLC/PLC-2 type command messages, each with
its appropriate logical addressing format.
PLC-5 controllers can also accept PLC/PLC-2 type command messages
with the PLC/PLC-2 logical addressing format. Before sending this type
of command to a PLC-5 station, you must first allocate a PLC-5 file (the
file number is the decimal equivalent of the PLC/PLC-2’s octal station
number) to simulate PLC/PLC-2 memory. In addition, PLC-5 controllers
can transmit PLC-5 and PLC/PLC-2 type command messages, each with
its appropriate logical addressing format.
Therefore, if you plan to transmit commands from a PLC-3 or a PLC-5 to
your computer, you should set up a computer buffer to simulate a PLC-3
or PLC-5 file and write computer application programs that are capable of
interpreting all the types of addressing formats that will appear in the
command messages.