151
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
6 What to Understand before Programming
6.5 General Rules for Applied Instructions
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
6.5.4
Handling functions of extension flag
In some applied instructions, the function can be extended by combining a specific special auxiliary relay
determined for each applied instruction. An example is explained below.
- When X000 turns ON, this instruction exchanges the
contents of D10 and the contents of D11 each other.
- If M8160 has been driven before the XCH instruction
and the source and destination of the XCH instruction
are specified to a same device, high-order 8 bits and
low-order 8 bits are exchanged with each other inside
the device.
- For returning this XCH instruction to the normal XCH
instruction, it is necessary to set M8160 to OFF.
When using an instruction requiring the function extension flag in an interrupt program, program DI instruction
(for disabling interrupt) before driving the function extension flag, and program EI instruction (for enabling
interrupt) after turning OFF the function extension flag.
6.5.5
Limitation in number of instructions
Limitation in the number of instructions and limitation in simultaneous driving
Some applied instructions can be used only up to the specified number of times.
When using above instructions beyond the allowable number of times of use
For instructions whose operands allow indexing, device numbers and numeric values in such instructions can
be changed by index registers.
By this indexing, when simultaneous multiple drive is not required, such instruction can be used as if they are
used beyond the allowable number of times.
→
Refer to "Subsection 5.7.3. Indexing example in instruction with limited number of use".
Instruction
name
Allowable number
of times of use
Remarks
FNC 52(MTR)
1
−
FNC 56(SPD)
8
(1 instruction/1 input
or less)
Pay attention so that this instruction does not overlap the input numbers of in
DVIT instruction, DOG inputs in ZRN instruction, zero point signal in DSZR
instruction, input interrupt numbers and high speed counter input numbers.
FNC 60(IST)
1
−
FNC 69(SORT)
1
−
FNC 70(TKY)
1
−
FNC 71(HKY)
1
−
FNC 75(ARWS)
1
−
FNC 77(PR)
2
−
FNC149(SORT2)
2
−
FNC186(DUTY)
5
(1 instruction/1 input
or less)
−
FNC280(HSCT)
1
−
X000
FNC 17
XCHP
D10
D11
X000
FNC 17
XCHP
D10
D10
Same number
M8160
M8160
Function extension flag
for the XCH instruction