122
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
4 Devices in Detail
4.11 Pointer [P and I]
4.11.3
Functions and operation examples of pointers for interrupt
→
For the details of interrupt function, refer to Chapter 35.
There are three types of pointers for interrupt. When in use, they are combined with IRET(FNC03),
EI(FNC04) and DI(FNC05) for interrupt return, enabling interrupt and disabling interrupt.
1. Pointers for input interrupt (delay interrupt): 6 points
→
For the details of input interrupt function, refer to Section 35.3 and Section 35.4.
The PLC can receive input signals from specific input numbers without influence of the operation cycle of the
PLC. By using these input signals as triggers, the PLC executes interrupt routine programs.
Because pointers for input interrupt can handle signals shorter than the operation cycle, use them for high
priority processing during sequence control and for control handling short pulses.
*1.
Cleared when the PLC mode switches from RUN to STOP.
Non-overlap of input numbers
Inputs X000 to X007 are used for high speed counters, input interrupt, pulse catch, SPD/ZRN/DSZR/DVIT
instructions and general-purpose inputs. When assigning functions, there should be no overlap between
those input terminals.
For example, when the input interrupt pointer I001 is used, X000 is occupied. As a result, "C235, C241,
C244, C246, C247, C249, C251, C252 and C254", "input interrupt pointer I000", "pulse catch contact M8170"
and "SPD instruction using X000" cannot be used.
Delay function of input interrupt
This input interrupt has a function to delay the execution of interrupt routine in units of 1ms.
The delay time is specified by the following pattern program.
This delay function can electrically adjust the mounting position of sensors for input interrupts without shifting
the actual position.
Input
Pointer for input interrupt
Interrupt disabling flag
ON duration or OFF duration of
input signal
Interrupt at rising
edge
Interrupt at falling
edge
X000
I001
I000
M8050
*1
5
µ
s or more
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
M8393
FNC 12
MOV
K
{{{
*
Delay time specifying program
Make sure to describe the delay time specifying
program shown on the left at the head of an
interrupt routine program.
Because this is a pattern program, change only
the delay time [1].
Only a constant (K) or data register (D) can be
used to specify the delay time*.
I
D8393
[1] Delay time (unit: ms)
FNC 03
IRET
Program to be processed by input interrupt
Contact for setting delay time
•
Interrupt program is finished
•
