35
FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
2 Overview (Sequence Program)
2.6 Program Memory and Devices
1
Introduction
2
Overview
3
Instruction
List
4
Devices
in Detail
5
Specified the
Device &
Constant
6
Before
Programming
7
Basic
Instruction
8
FNC00-FNC09
Program Flow
9
FNC10-FNC19
Move & Compare
10
FNC20-FNC29
Arith. & Logic
Operation
Caution
Programs (when a memory cassette is not attached), latched (battery backed) type device values and clock data is not
backed up correctly when the battery voltage becomes low due to expiration of the battery life or another reason.
In such a case, clear latched (battery backed) type devices, transfer programs again (when a memory cassette is not
attached), and then set initial values and clock data if necessary.
→ For a rough guide to the life and replacement of the battery, refer to the PLC User’s Manual
[Hardware Edition].
→ For the latched type device initialization method, refer to Subsection 2.6.5.
b) FX3G PLCs
*1. These registers can be changed from the general type to the latched (battery backed) type by the parameter
setting when the optional battery is installed.
*2. Some devices are cleared when the PLC status switches from STOP to RUN.
→ For special data registers, refer to Chapter 37.
*3. The clock data is held by the electricity charged in the large-capacity capacitor built in the PLC.
When the voltage of the large-capacity capacitor becomes low, the clock data is not held correctly.
The capacitor can hold the clock data for 10 days (when the ambient temperature is 25
°C
) in the full charge state
(achieved by powering ON the PLC for 30 minutes or more).
The clock data is backed up by the battery when the optional battery is installed and the battery mode is selected
in the parameter setting.
Item Power OFF Power
OFF→ON STOP→RUN RUN→STOP
Data register (D)
General type Cleared.*1 Does not change. Cleared.
Does not change while M8033 is ON.
Latched (EEPROM
backed) type Does not change.
File type Does not change.
Special type Cleared. Set to initial
values.*2 Does not change.*2
Extension register (R) General type Cleared.*1 Does not change.
Extension file register
(ER) 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.
For 1 ms Cleared. Does not change. Cleared.
Does not change while M8033 is ON.
Retentive type for 100
ms (EEPROM backed) Does not change.
Retentive type for 1
ms(EEPROM backed) Does not change.
Counter present value
register (C)
General type Cleared. Does not change. Cleared.
Does not change while M8033 is ON.
Latched (EEPROM
backed) type Does not change.
High speed type
(EEPROM backed) Does not change.
Clock data Present value
(EEPROM backed) Does not change.*3