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2.7 Data Clear Processing
This section describes how to clear data in the CPU module and settings required for clearing latch data.
(1) Clearing data
Data in the CPU module are cleared when the reset operation (using the RUN/STOP/RESET switch or by
powering off and on the module) is performed. However, the following data cannot be cleared by these
operations:
• Data in the program memory
• Data in the standard ROM
• Data in a memory card or SD memory card
• Data in latch-specified devices ( Page 75, Section 2.7 (4))
(2) Clearing data that cannot be cleared by the reset operation
(a) Data in the program memory
Clear the data by:
• Selecting the "Clear Program Memory" checkbox in the Boot File tab of the PLC parameter dialog box.
• Configuring settings on the screen opened by selecting [Online]  [Delete PLC Data] in a programming
tool.
(b) Data in the standard ROM
Data stored on the standard ROM are automatically cleared when new data is written on it.
(c) Data in a memory card or SD memory card
Clear the data by configuring settings on the screen opened by selecting [Online] ï‚®ï€ [Delete PLC Data] in a
programming tool.
(d) Data in latch-specified devices
Refer to Page 75, Section 2.7 (4).
(3) Device latch specification
Set a latch range for each latch-target device in the Device tab of the PLC parameter dialog box.
( Page 123, Section 3.3 (4))
(a) Latch range setting
Two different types of latch ranges can be set using a programming tool:
• Latch clear operation enable range (Latch (1) Start/End)
This is a range within which data can be cleared by a latch clear operation.
• Latch clear operation disable range (Latch (2) Start/End)
This is a range within which data cannot be cleared by a latch clear operation.
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