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23 LATCH FUNCTION
23.1 Latch with Battery
Applicable devices and labels
This section describes the devices/labels that can be latched.
Applicable devices
The devices below can be latched. However, local devices cannot.
*1 When "Use Common File Register in All Programs" is enabled, any of the number of points is registered within the range for Latch (2).
Also, the range can be specified in "Latch (2)" of "Latch Range Setting" (values out of the specified range are cleared to 0).
• When "Use File Register of Each Program" is enabled, the latch range for file registers cannot be specified
(the whole range for file registers is retained).
• When the file register file which should be used is changed by the QDRSET instruction, the latch range
setting for file registers is disabled. After the change, the whole range for file registers is retained regardless
of the latch range setting.
Applicable labels
The labels below can be latched.
Device
Specification method
Applicable latch type
Internal relay (M)
Specify the latch range.
Latch (1) or Latch (2)
Link relay (B)
Specify the latch range.
Latch (1) or Latch (2)
Annunciator (F)
Specify the latch range.
Latch (1) or Latch (2)
Edge relay (V)
Specify the latch range.
Latch (1) or Latch (2)
Timer (T)/Long timer (LT)/Retentive timer (ST)/Long
retentive timer (LST)
Specify the latch range.
Latch (1) or Latch (2)
Counter (C) and Long counter (LC)
Specify the latch range.
Latch (1) or Latch (2)
Data register (D)
Specify the latch range.
Latch (1) or Latch (2)
Link register (W)
Specify the latch range.
Latch (1) or Latch (2)
Latch relay (L)
Specify the number of points (latch is performed the same
number of times as the specified number of points).
Latch (2) only
File register (R, ZR)
Specify the number of points (latch is performed the same
number of times as the specified number of points). Specify
the latch range.
Latch (2) only
Label type
Class
Global label
VAR_GLOBAL_RETAIN
Local label of a program block
VAR_RETAIN
Local label of a function block
VAR_RETAIN
VAR_OUTPUT_RETAIN
VAR_PUBLIC_RETAIN
Summary of Contents for MELSEC iQ-R-R00CPU
Page 2: ......
Page 151: ...9 MONITOR FUNCTION 9 1 Real Time Monitor Function 149 9 MEMO ...
Page 323: ...18 SEQUENCE SCAN SYNCHRONIZATION SAMPLING FUNCTION 321 18 MEMO ...
Page 330: ...328 20 ROUTING SETTING 20 3 Precautions MEMO ...
Page 423: ...26 BASIC CONCEPT 26 8 State Transition of the Redundant System 421 26 MEMO ...
Page 1014: ...1012 APPX Appendix 15 Added and Enhanced Functions MEMO ...
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