Filter
Top Products
739
FX3S/FX3G/FX3GC/FX3U/FX3UC Series
Programming Manual - Basic & Applied Instruction Edition
33 Extension File Register Control – FNC290 to FNC299
33.6 FNC295 – INITER / Initialize ER
31
FNC277-FNC279
Data
Transfer 3
32
FNC280-FNC289
High-Speed
Processing 2
33
FNC290-FNC299
Extension File
Register Control
34
FNC300-FNC305
FX
3U
-CF-ADP
35
SFC•STL
Programming
36
Interrupt
Function
37
Special Device
38
Error Code
A
Version Up
Information
B
Execution Times
Operation
• Extension file registers (ER) [inside the memory cassette]
Caution
About 25 ms is required to initialize one sector.
When initializing two or more sectors, take either measure shown below.
• Set a large value to the watchdog timer D8000 using the following program
Guideline of the watchdog timer set value
A value acquired by the following procedure can be regarded as the guideline of the watchdog timer set value.
If an acquired value is 200 ms or less, however, it is not necessary to change the watchdog timer set value.
1) Write a program to be executed from GX Works2 to the PLC.
[Online]→[Write to PLC...]
2) Set the current value of D8000 (unit: ms) to "1000" using the [Modify Value] function in GX Works2.
[Debug]→[Modify Value]
3) Set the PLC mode to RUN, and execute the program. (Execute this instruction also.)
4) Monitor the maximum scan time D8012 (unit: 0.1 ms) using the device/buffer memory batch monitor function in
GX Works2.
5) Set the watchdog timer to the maximum scan time (D8012) or more.
D8012 stores the maximum scan time in increments of 0.1 ms.
Rough guide to the watchdog timer set value D8000 (unit: ms) is the "value stored in D8012 divided by 10" added
by 50 to 100.
• Setting the WDT (FNC 07) instruction just before and after the INITER instruction as shown below:
If the processing time of the INITER command exceeds 200 ms, set the watchdog timer value D8000 (unit: ms) to the
processing time or more.
2. Allowable number of writes to the memory
Note the following cautions on access to extension file registers.
• Data can be written to the memory cassette (flash memory) up to 10,000 times.
Every time the INITR (FNC292), RWER (FNC294) or INITER (FNC295) instruction is executed, it is counted as a
write to the memory. Make sure not to exceed the allowable number of writes.
When a continuous operation type instruction is used, data is written to the memory in every operation cycle of the
PLC. To prevent this, make sure to use a pulse operation type instruction.
• Execution of the LOADR (FNC290), SAVER (FNC291) or LOGR (FNC293) instruction is not counted as a write to
the memory. However, it is necessary to initialize the writing target sector before executing the SAVER (FNC291)
or LOGR (FNC293) instruction.
Every time the INITR (FNC292) or INITER (FNC295) instruction is executed, it is counted as a write to the memory.
Make sure not to exceed the allowable number of writes.
Device number
Current value
Before execution After execution
H1234 HFFFF
+1
H5678 HFFFF
+2
H90AB HFFFF
...
...
...
+(2048×n)-1
HCDEF HFFFF
S
S
S
S
M8002
FNC 12
MOV
K
D8000
Initial pulse
The watchdog timer is reset.
FNC295
INITER
n
FNC 07
WDT
FNC 07
WDT
The watchdog timer is reset.
Command
input
S