Latch Function - Mitsubishi L02CPU User Manual

3.4

Latch Function

This function holds data in each device of the CPU module when:
• the CPU module is powered off and then on,
• the CPU module is reset, or
• a power failure occurred exceeding the allowable momentary power failure time.
Data in each device of the CPU module are cleared and set back to its default (bit device: off, word device: 0) when
this function is not used. By using this function, the operation can be continued with the previous data even after
powering off the CPU module while the data are managed by a sequential control. Program operation does not change
regardless of the latch
(1) Devices that can be latched
Set the device to latch among the following. (By default, only the latch relay is allowed to be latched.)
• Latch relay (L)
• Edge relay (V)
• Counter (C)
• File register (ZR)
When the battery life-prolonging function is set, the latch function is disabled. (
(2) Latch range setting
Set the following.
Project Window
• Latch clear is enabled (Latch (1) Start/End): The latch range that can be cleared by remote latch clear
operation
• Latch clear is disabled (Latch (2) Start/End): The latch range that cannot be cleared by remote latch clear
operation
Set latch ranges by the start and
end device numbers.
• Link relay (B)
• Timer (T)
• Data register (D)
• Extended data register (D)
[Parameter] [PLC Parameter]
CHAPTER 3 CPU MODULE FUNCTIONS
• Annunciator (F)
• Retentive timer (ST)
• Link register (W)
• Extended link register (W)
Page 166, Section 3.30)
[Device]
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