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7 ONLINE CHANGE
7.1 Online Ladder Block Change
7 ONLINE CHANGE
This chapter describes online change.
7.1 Online Ladder Block Change
Writes the portion edited on the ladder edit window of the engineering tool to the CPU module in increments of ladders. Edited
contents spanning multiple files or multiple portions can be written to the CPU module at once.
For details on the operating procedure of online ladder block change on engineering tools, refer to the
following.
GX Works3 Operating Manual
Editable contents
Within a program block, instructions and pointers (P, I) can be added, changed, or deleted. Also, as POU unit, program blocks
can be added, changed, or deleted. However, when the program/FB file is not in agreement between engineering tool and a
CPU module, it cannot be added, changed, or deleted.
Range changeable in a single session
The following shows the number of steps and number of ladder blocks which can be changed in a single session.
• Number of ladder blocks in a file: 64 blocks or less (2048 steps or less)
• The total of the changed circuit block count in all files: 256 blocks or less
• The total capacity of the program file and the FB file after a change: 1 M byte or less
Online ladder block change during the boot operation
If online change of ladder block is executed from the SD memory card during boot operation, the corresponding file in the SD
memory card, which is the boot source, can be changed as well.
Precautions
This section describes the precautions on using online ladder block change.
Prohibited operation at online ladder block change
When an online change of ladder block, if the power is turned OFF or a reset is made, the process does not end normally.
Such operation is made, execute rewriting to the PLC.
When deleting OUT instruction which is on
When deleting an OUT instruction (coil) which is not necessary for control, be sure to check that the OUT instruction is off
before deleting it. If the OUT instruction is deleted without turning it off in advance, the output will be retained.
Program file not registered in program setting
A program file which is not registered in parameter setting cannot be written.
Initializing the last execution if the ladder at online ladder block change has an FB call
• If a subroutine type FB is called in a FB definition, the execution information of the previous time in the FB definition of the
subroutine type FB is not initialized.
• If a macro type FB is called in the FB definition of a subroutine type, the execution information of the previous time in the
part equivalent to the macro type FB is not initialized either.