Mitsubishi Electric CC-Link IE Basic Reference Manual page 29

Precautions
■Latched devices of the CPU module
If data in latched devices of the CPU module is cleared to zero in a program when the CPU module is powered off and on or
reset, the data may be output without being cleared to zero, depending on the timing of link scan and link refresh. Take the
following actions so as not to output the data in the latched devices of the CPU module.
CPU module device
*1
File register (R, ZR)
Latch relay (L)
Devices within the latch range, extended data register (D)
*2
register (W)
*1 For MELSEC iQ-F, the file register (R) is latched if this register is specified to be included in the latch range.
*2 The devices are available for MELSEC-Q/L. ( User's Manual (Function Explanation, Program Fundamentals) for the CPU module
used)
■Boundary between extended data register (D) and extended link register (W)
Do not set the refresh range beyond the boundary between the user device and extended data register (D)
*1
register (W) .
*1 The devices are available for MELSEC-Q/L. ( User's Manual (Function Explanation, Program Fundamentals) for the CPU module
used)
How to disable the device data
Use the device initial value to clear the device to zero.
Delete from the refresh settings
*2
and extended link Delete all the latch range settings.
*1
or extended link
7 FUNCTIONS
27
7.1 Cyclic Transmission
7