111
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]
1
In
troduct
io
n
2
Ov
e
rv
ie
w
3
In
st
ru
ct
ion
Li
st
4
D
evi
ce
s
in
De
ta
il
5
Speci
fied t
h
e
D
evi
ce &
C
onst
a
nt
6
Bef
o
re
Pr
ogr
a
m
m
ing
7
Bas
ic
In
st
ru
cti
o
n
8
FNC0
0
-FNC0
9
P
ro
g
ra
m F
lo
w
9
FNC1
0
-FNC1
9
M
ov
e
&
C
om
par
e
10
FNC
20-
FNC
2
9
Ar
ith.
&
Logi
c
O
per
at
io
n
4.9.3
Structures of extension registers and extension file registers
One extension register consists of 16 bits. Extension registers can be used in 16-bit and 32-bit applied
instructions for operation in the same way as data registers.
1) 16-bit type
One extension register (consisting of 16 bits) can handle a numeric value in the range from
−
32768 to
+32767.
A numeric value is read from and written to an extension register by applied instructions usually.
Or a numeric value can be directly read from and written to an extension register from a display unit,
display module, or programming tool.
2) 32-bit type
Two serial extension registers (consisting of 32 bits) can express a 32-bit numeric value in the range from
−
2,147,483,648 to +2,147,483,647. (A larger number register handles high-order 16 bits, and a smaller
number register handles low-order 16 bits.)
• In the case of 32 bit type, when an extension register on the low-order side (example: R0) is specified, the
subsequent serial number on the high-order side (example: R1) is automatically occupied.
Either an odd or even device number can be specified for the low-order side, but it is recommended to
specify an even device number for the low-order side under consideration of the monitoring function of
display units, display modules, and programming tools.
4.9.4
Initialization of extension registers and extension file registers
The contents of extension registers are backed up by the built-in battery even when the power is turned OFF
or when the PLC mode switches from STOP to RUN.
When initializing the contents of extension registers, clear them using a sequence program or GX Developer.
1. When clearing the data using a program
• When initializing some extension registers (R)
Example: When initializing (clearing) R0 to R199
• When 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 clearing the data 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.
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
16384
b15
Sign
0: Positive
number
1: Negative
number
b0
High
order
Low
order
R0, ER0 (16 bits)
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
1
2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
16384
b31
Sign
0: Positive
number
1: Negative
number
b0
High
order
Low
order
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
32768
65536
131,
07
2
262,
14
4
524,
28
8
1,
048,
5
7
6
2,
097,
1
5
2
4,
194,
3
0
4
8,
388,
6
0
8
16,
777
,216
33,
554
,432
67,
108
,864
134,
21
7,
728
268,
43
5,
456
536,
87
0,
912
1,
073,
7
41,
824
R1, ER1 (high-order 16 bits)
R0, ER0 (low-order 16 bits)
FNC 16
FMOVP
K0
R0
K200
Command
Command
FNC 292
INITRP
R0
K2
The current value is initialized to "FFFF
H
" in
R0 to R4095.
