Rockwell Automation 1772-LP3 PLC - 2/30 Programmable Controller Programming and Operations Manual - Manual (Page 304)

Troubleshooting Aids
Chapter 18
18Ć5
The Temporary End instruction can be used to test or debug a program up
to the point where it is inserted. It acts as a program boundary because
instructions below it in user program are not scanned or operated upon.
Instead, the processor immediately scans the I/O image table followed by
user program from the first instruction to the Temporary End instruction.
When the Temporary End instruction is inserted, the rungs below it,
although visible and accessible, are not scanned. Their content can be
edited, if desired. The displayed section of user program made inactive
by the Temporary End instruction will contain the message INACTIVE
AREA in the lower right-hand corner of the screen.
The Temporary End instruction can be inserted in either of two ways:
Cursor to the last rung of the main program to be kept active. Position
the cursor on the output instruction. Press
[INSERT] [T. END]
Cursor to the first rung of the main program to be made inactive.
Position the cursor in the first instruction in the rung. Press
[INSERT] [
←
] [T. END]
To remove this instruction, position the cursor on it and press [REMOVE]
[ T. END]
To enter a rung after the T. END instruction, press [
↓
] and then enter the
new rung. If the [
↓
] key is not pressed, the rung will be inserted above the
T. END statement.
Attempting to use the Temporary End instruction in any of the following
ways will either be prevented by the industrial terminal or result in a
run-time error:
Using more than one temporary End instruction at a time.
Using the instruction in subroutine area.
Inserting or removing the instruction on-line during on-line
programming.
Placing the instruction in the path of the Jump instruction.
An illegal OP code is an instruction code that the processor does not
recognize. It will cause the processor to fault and will be displayed as an
ERR message in the ladder diagram rung in which it occurs. The 4-digit
hex value of the illegal OP code is displayed above the ERR message by
the T3 industrial terminal.
The illegal OP code ERR message should not be confused with ERR
messages caused when T1 or T2 industrial terminal is connected to a
processor that was programmed using a T3 industrial terminal. (See
18.4
Temporary End Instruction
18.5
ERR Message for an Illegal
OP Code