787
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
35 Interrupt Function and Pulse Catch Function
35.3 Input Interrupt (Interrupt Triggered by External Signal) [Without Delay Function]
31
FN
C
275-FN
C
279
Da
ta
Tr
ans
fe
r 3
32
FN
C
280
-F
N
C
28
9
H
igh Speed
Pr
oces
si
ng 2
33
FN
C
290-FN
C
299
Ext
ensi
on Fi
le
R
egi
st
er
34
SF
C
•S
T
L
Pr
o
g
ra
m
m
in
g
35
In
te
rru
p
t
Funct
ion
36
Sp
e
cia
l De
vic
e
37
E
rro
r C
o
d
e
A
V
e
rs
ion U
p
In
fo
rm
a
tio
n
B
Ex
ec
ut
ion Ti
m
e
s
C
Appl
ic
ab
le
In
st
ru
ct
ion Li
st
4. Number and operation of (six) interrupt pointers
*1.
Cleared when the PLC mode is changed from RUN to STOP.
5. How to disable each interrupt input
When either one among M8050 to M8055 is set to ON in a program, interrupts from a corresponding input
number are disabled.
(Refer to the above table for the correspondence.)
6. Cautions
1) Do not use an input twice or more
Make sure that an input relay number used as an interrupt pointer is not used in high speed counters,
pulse catch functions and applied instructions such as FNC 56 (speed detection) which use the same
input range.
2) Automatic adjustment of the input filter
When an input interrupt pointer I
0
is specified, the input filter of the input relay is automatically
changed to the input filter for high speed receiving.
Accordingly, it is not necessary to change the filter value using REFF (FNC 51) instruction or special data
register D8020 (input filter adjustment).
The input filter of an input relay not being used as an input interrupt pointer operates at 10 ms (initial
value).
3) Pulse width of input interrupt
For executing input interrupt by an external signal, it is necessary to input the ON or OFF signal having
the duration shown in the table below or more.
*1.
When using the input filter at the filter value of 5
µ
s or when receiving a pulse whose response
frequency is 50 k to 100 kHz using a high speed counter, perform the following:
-
Make sure that the wiring length is 5 m or less.
-
Connect a bleeder resistor of 1.5 k
Ω
(1 W or more) to an input terminal, and make sure that the
load current of the open collector transistor output in the counterpart equipment is 20 mA or
more including the input current in the main unit.
4) Using a pointer number twice or more
It is not possible to program an interrupt at the rising edge and an interrupt at the falling edge for an input
such as I001 or I000.
Input number
Pointer number
Interrupt disable command
Interrupt at rising edge
Interrupt at falling edge
X000
I001
I000
M8050
*1
X001
I101
I100
M8051
*1
X002
I201
I200
M8052
*1
X003
I301
I300
M8053
*1
X004
I401
I400
M8054
*1
X005
I501
I500
M8055
*1
Input number
Input filter value when "0" is set
X000 to X005
5
µ
s
*1
I
0
0: Interrupt at falling edge, 1: Interrupt at rising edge
0 to 5 according to the inputs X000 to X005