Rockwell Automation 1772-L8_LW_LWP_LX_LXP,D17726.5.8 User Manual - Manual (Page 389)

Program Editing
Chapter 24
24-16
The procedure for online programming in run/program mode is similar to
the procedure for editing in program mode. However, the following three
keys have a special purpose in online programming:
[Record]
[Cancel
Command]
[Data Init]
Use the [Record] key to enter a change to your program. Once pressed, the
changed program is active.
Use the [Cancel Command] key to abort any online programming
operation prior to pressing the [Record] key. Pressing [Cancel Command]
restores the ladder diagram display and program logic to its original state
prior to the online programming operation. You can also use it to
terminate the online programming mode.
The [Data Init] key performs two functions in the online
programming mode:
It allows entry of BCD data values (stored at the instruction address).
It resets status bits.
Use the [Data Init] key when programming a data instruction whose
address is not currently being used in the program. If you do not use
[Data Init], data at the new address (possibly remaining from previous
programming) may interfere with proper machine operation when you
insert the new instruction into the program.
ATTENTION: When the address of a new instruction
duplicates the address of other instructions in the program, the
[Data Init] key should not be used without first assessing the
consequences. Pressing the [Data Init] key zeros out the status
bits stored at the existing instruction address. This may cause
unwanted machine motion and result in equipment damage
and/or injury to personnel.
Data Initialization Key