Rockwell Automation 1775-S5_SR5,D17756.5.5 User Manual PLC-3 FAMILY I/0 - Manual (Page 117)

Diagnostics Methods
Chapter 7
7-5
Figure 7.2
Example Procedures Showing ON_ERROR Nesting
MAIN
SUB1
Line Number Procedure Word
1
8
Error Block
160
2
1
1
8
0
11248
10
ON_ERROR @SUB1
7.2 = 1000
0
1
2
3
4
5
Contents (decimal)
•
•
•
•
•
•
•
•
•
•
$25:0 = N
•
•
In this example (Figure 7.2), an addressing error in line 10 of procedure
MAIN causes the ON_ERROR command to execute. The ON_ERROR
command calls for execution of procedure SUB1. But SUB1 also contains
an error. The error in SUB1 is the last one detected, so it is the one finally
reported in the error block. Since procedure SUB1 is called by the
ON_ERROR command in procedure MAIN, the nesting for SUB1 is 2
levels deep.