Chapter 6 PLC Programming 131
The
Address/Symbols
option lists the instruction addresses and
their descriptions. Only the processor addresses used in the ladder
logic diagram are listed.
The
Instruction Comments
option displays the instruction com-
ments. Note that on the ladder logic diagram the instruction com-
ments will write over the address comments. This means that if an
address has both instruction and address comments, only the instruc-
tion comment will be printed.
The
Symbol Groups
option contains the list and description of the
symbol groups. A PLC programmer can create symbols for each input/
output device. From then on, the programmer can use the symbol to
place the I/O device. For example, you can create a symbol called PB0
for the input I:0/0. Then instead of typing I:0/0, you can simply type
PB0 to place the input device in the ladder diagram.
Program Files
The
Program Files
section of the report option in the dialog box has
two options. These options are the
Program File List
and
Program
Files.
The
Program File List
has a list of the ladder logic diagrams. It
will always list file 0, file 1, and file 2. File 0, or
SYS
0, is used to hold
the status bits or flag bits. These bits are S2, S3, S5, and such. File 1, or
SYS
2, is reserved. Therefore, file 0 and file 1 are system files. File 2,
or LAD2, contains the main ladder logic diagram. If the PLC project
uses subroutines, then the project may have a file 3, file 4, and file 5
until the last file. Therefore, in addition to file 0, file 1, and file 2, a PLC
project can have file 3, or LAD3, through file 255, or LAD255, if there is
enough RAM memory available on the PLC system. You should select
this report option.
The
Program Files
option displays the ladder logic diagrams of
the files in the report. You should select this report option.
Data Files
The
Data Files
section has three options. These options are
Data
File
List,
Data
Files, and
Memory
Usage.
A
Data File List
specifies the list of data files available for your
PLC project.
The
Data Files
option allows you to specify which data file you want
to include in your report or the range for which data file will be printed.
Memory Usage
specifies the range for which a data file should be
printed. Memory usage specifies the range of all data tables used in
the PLC project.
Occasionally, you may want to select the
Data File List
and
Data
Files
options. This data can be beneficial for troubleshooting the PLC
system. Figure 6-35 displays how to select a report option in the
Report
Preview
dialog box.
Instruction comments:
Comments used to
describe the input/output
instructions.