36
FX
3G
/FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
2 Overview (Sequence Program)
2.6 Program Memory and Devices
2.6.2
Memory operations and latched (battery backed)
(power ON/OFF and RUN/STOP)
1. Backup operation
The operations of the data memory, bit device memory and program memory in FX
3G
/FX
3U
/FX
3UC
PLCs are
classified as shown below:
1) Types of program memory
2) Types of word device memory
a) FX
3U
/FX
3UC
PLC
*1.
The contents of the program memory and device values are not backed up correctly in FX
3U
/FX
3UC
PLCs when the battery voltage becomes lower than the holding voltage if a memory cassette is not
attached.
*2.
Device values are not backed up correctly when the battery voltage becomes lower than the holding
voltage.
*3.
Some devices are cleared when the PLC status switches from STOP to RUN.
→
For special data registers, refer to Chapter 37.
*4.
An optional memory cassette is required.
Item
Power OFF
Power
OFF
→
ON
STOP
→
RUN
RUN
→
STOP
Parameter
Does not change.
*1
Sequence program
Does not change.
*1
Comment
Can be secured by
parameter setting.
Does not change.
*1
File register
Does not change.
*1
Item
Power OFF
Power
OFF
→
ON
STOP
→
RUN
RUN
→
STOP
Data register (D)
General type
Cleared.
Does not change.
Cleared.
Does not change while M8033 is ON.
latched (battery
backed) type
Does not change.
*2
File type
Does not change.
*1
Special type
Cleared.
Set to initial
values.
*3
Does not change.
*3
Extension register
(R)
latched (battery
backed) type
Does not change.
*2
Extension file
register (ER)
*4
File type
Does not change.
Index register (V, Z) V, Z
Cleared.
Does not change.
Timer present value
register (T)
For 100 ms
Cleared.
Does not change.
Cleared.
Does not change while M8033 is ON.
For 10 ms
Cleared.
Does not change.
Cleared.
Does not change while M8033 is ON.
Retentive type for 100 ms
(battery backed)
Does not change.
*2
Retentive type for 1 ms
(battery backed)
Does not change.
*2
Counter present
value register (C)
General type
Cleared.
Does not change.
Cleared.
Does not change while M8033 is ON.
latched (battery
backed) type
Does not change.
*2
High speed type
(battery backed)
Does not change.
*2
Clock data
Present value
(battery backed)
Does not change.
*2