Page 309 - Programmable Logic Controllers, Fifth Edition - Mobile version

Data file folders Data file window
Data Files Input Tabl e
Cross Reference
O:0-OUTPUT 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
I:1-INPUT I:1.0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0
S2-STATUS I:2.0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
B3-BINARY
T4-TIMER Radix: Binary Table:
C5-COUNTER O:0:Output
R6-CONTROL Address I:1:Input
S2: Status
N7-INTEGER B3: Binary
F8-FLOAT T4: Timer
C5: Counter
R6: Control
N7: Integer
F8: Float
Figure 13-15 Data file folder and window.
Source: Courtesy of TheLearningPit.

Figure 13-15 shows the data file folder and window The status of the bit(s) (on or off) and the length of time
for the Allen-Bradley SLC 500 PLC and its associated the bit(s) remained on or off (in hours, minutes, seconds,
RSLogix software. The data file folder allows the user and hundredths of a second) are displayed. In a contact
to determine the status of I/O files as well as the sta- histogram file, the accumulated time indicates the total time
tus file (S2), binary file (B3), timer file (T4), counter that the histogram function was running. The delta time
file (C5), control file (R6), integer file (N7), and the of the contact histogram indicates the elapsed time between
floating-point file (F8). Always be careful when manip- the changes in states. Contact histograms are extremely
ulating data using the data monitor function. Changing
data could affect the program and turn output devices
on or off. Stop PB Start PB Motor control relay
I:1/2
I:1/1
When troubleshooting a PLC, it may be necessary to 0 O:2/1
locate each instance of a particular address in the ladder
program. The cross reference function searches all pro- Motor control relay
gram files to locate each instance of the selected address. O:2/1
A user can then trace the operation by finding all the
places where a particular output coil or contact with the Motor control relay Run pilot light
same address is used in the program. Figure 13-16 shows O:2/1 O:2/3
a sample cross reference report for the Allen-Bradley 1
SLC 500 PLC and its associated RSLogix software. Its
contents can be summarized as follows:
Cross Reference Report - Sorted by Address
• The report contains all the addresses used in the
program.
• Addresses are displayed in the same order as the
data table files.
• The address that the search was performed for
(O:2/1) is highlighted.
• The description for each address is displayed.
• Listing includes the instruction type, program file,
and rung number for each address.
• Each occurrence of the address is displayed, starting Sort By Symbol Refresh Help
with program file 2 and rung 0.
The contact histogram function allows you to view the Figure 13-16 Sample cross reference report.
transition history (the on and off states) of a data table value. Source: Courtesy of TheLearningPit.

290 Chapter 13 PLC Installation Practices, Editing, and Troubleshooting

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