Mitsubishi Electronics FX3G User Manual
736
FX
3S
/FX
3G
/FX
3GC
/FX
3U
/FX
3UC
Series
Programming Manual - Basic & Applied Instruction Edition
33 Extension File Register Control – FNC290 to FNC299
33.5 FNC294 – RWER / Rewrite to ER
3. Allowable number of writes to the memory
Note the following cautions on access to extension file registers.
• In FX
• In FX
3U
/FX
3UC
PLCs
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.
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.
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.
• In FX
3G
/FX
3GC
PLCs
Data can be written to the memory cassette (EEPROM) up to 10,000 times, and to the built-in memory (EEPROM)
up to 20,000 times.
Every time the RWER (FNC294) 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)instruction is not counted as a write to the memory.
up to 20,000 times.
Every time the RWER (FNC294) 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)instruction is not counted as a write to the memory.
Data backup method
When the contents of extension file registers (ER) and extension registers (R) should not be lost, back up the current
values (data) of extension file registers (ER) and extension registers (R) in advance using the following procedure:
1) Set the PLC mode to STOP.
2) Create a new project in GX Works2.
values (data) of extension file registers (ER) and extension registers (R) in advance using the following procedure:
1) Set the PLC mode to STOP.
2) Create a new project in GX Works2.
This step is not necessary if it is alright to overwrite the current project.
3) Read the contents of extension file registers (ER) and extension registers (R) to GX Works2.
[1] Select “Online”
→ “Read from PLC...” to
display the Online Data Operation dialog box.
[2] Click "PLC Parameter/Network Parameter"
and "Device Data/File Register" to check mark
each of them.
each of them.
[3] Click the [Detail] button of the device memory
to display the "Device Data Detail Setting"
dialog box.
dialog box.
[4] Enter the file name to be saved to "Device
Data Name".
[5] Check "Ext. register" and "Ext. file register"
*1
of "Device Data Name", and click the [OK]
button.
button.
[6] Click [Execute] button to execute reading.
[7] When reading is completed, save the project.
[7] When reading is completed, save the project.
*1.
The extension file register range cannot be set
in GX Developer whose version is earlier than
Ver. 8.18U or in GX Works2.
in GX Developer whose version is earlier than
Ver. 8.18U or in GX Works2.