114
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
4 Devices in Detail
4.9 Extension Register [R] and Extension File Register [ER]
2. Sectors of extension registers and extension file registers
According to the data structure, extension registers and extension file registers are divided into sectors. One
sector consists of 2048 devices. The table below shows the head device in each sector.
4.9.7
Cautions on using extension file registers
1. Cautions on writing data to extension file registers
Because extension file registers are stored in the flash memory inside a memory cassette, pay attention to
the following points:
• When writing data to extension file registers by SAVER instruction
Before executing this instruction, initialize sectors to be written in advance. After initialization, store data to
be written to extension registers.
In FX
3UC
PLCs Ver.1.30 or later, it is not necessary to initialize sectors to be written when using RWER
instruction.
• When writing data to extension file registers by LOGR instruction
Before starting to log data, initialize sectors to be written in advance.
• When using INITR instruction
This instruction initializes the contents of specified extension registers and extension file registers.
When initializing only extension file registers by this instruction, make sure to temporarily move the
contents of extension registers to unused extension registers or unused data registers before executing
this instruction.
When initializing only extension file registers in FX
3UC
PLCs Ver.1.30 or later, use INITER instruction.
2. Initialization of extension file registers
Because the contents of extension file registers are stored in the flash memory inside a memory cassette,
execute the data clear operation by a sequence program or GX Developer to initialize them.
1) When initializing extension file registers by a program
a) Initializing only extension file registers in units of a sector [Ver.1.30 or later]
Example: When initializing ER0 to ER4095 (initializing two sectors starting from ER0)
b) Initializing extension registers and extension file registers in units of sector
Example: When initializing R0 to R4095 and ER0 to ER4095 (initializing two sectors starting from R0
and ER0)
2) When initializing extension file registers using GX Developer
Select [Online]
→
[Clear PLC memory...] in GX Developer, and clear [Data device].
This operation initializes the contents of timers, counters, data registers, file registers and extension
registers.
Sector
No.
Head
device
No.
Device range
Sector
No.
Head
device
No.
Device range
Sector 0
R0
ER0 to ER2047, R0 to R2047
Sector 8
R16384
ER16384 to ER18431, R16384 to R18431
Sector 1
R2048
ER2048 to ER4095, R2048 to R4095
Sector 9
R18432
ER18432 to ER20479, R18432 to R20479
Sector 2
R4096
ER4096 to ER6143, R4096 to R6143
Sector 10 R20480
ER20480 to ER22527, R20480 to R22527
Sector 3
R6144
ER6144 to ER8191, R6144 to R8191
Sector 11 R22528
ER22528 to ER24575, R22528 to R24575
Sector 4
R8192
ER8192 to ER10239, R8192 to R10239
Sector 12 R24576
ER24576 to ER26623, R24576 to R26623
Sector 5
R10240
ER10240 to ER12287, R10240 to R12287
Sector 13 R26624
ER26624 to ER28671, R26624 to R28671
Sector 6
R12288
ER12288 to ER14335, R12288 to R14335
Sector 14 R28672
ER28672 to ER30719, R28672 to R30719
Sector 7
R14336
ER14336 to ER16383, R14336 to R16383
Sector 15 R30720
ER30720 to ER32767, R30720 to R32767
Command input
FNC 295
INITERP
R0
K2
The current value is initialized to "FFFF
H
" in ER0
to ER4095.
Command input
FNC 292
INITRP
R0
K2
The current value is initialized to "FFFF
H
" in R0 to R4095 and
ER0 to ER4095.
