IDEC SmartAXIS Touch FT1A Series User Manual

4 Special Functions
3-74 SmartAXIS Touch User's Manual
4.9 Interrupt Input
This section explains interrupt inputs, which can be used to interrupt execution of a ladder program by means of an
external input to execute a subroutine.
The interrupt input can only be used when ladder program is selected as the programming language.
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Feature Description
In the processing of normal ladder programs, execution proceeds iteratively from beginning to end, but if an interrupt
input is used, ladder program execution can be temporarily paused in order to execute a subroutine, irrespective of
scans. With an interrupt input, a subroutine of predetermined label No. is run as an interrupt program when the
external input is turned ON. When processing of the subroutine program is ended, execution of the interrupt program
resumes. Up to 4 interrupt inputs can be set for external input groups 2 to 5.
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Function Specification
The Touch inputs can be configured as normal inputs, high-speed counters, catch inputs, interrupt inputs, or
frequency measurement. To use catch inputs, specify Interrupt Input for the applicable group under Function Area
Settings.
Jump destination label Nos. are stored in special data registers (D8033 to D8035, D8037, D8038).
Whether or not an interrupt input is allowed can be checked by the interrupt input state of the special internal relay
(ON: Allowed, OFF: Prohibited).
The 12-I/O type cannot use external inputs I6 and I7 as interrupt inputs on Touch.
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Disable and Enable Interrupts
The interrupt inputs I2, I3, I4, and I5 and timer interrupt are normally enabled while the Touch is running, and can
also be individually disabled using the DI instruction or enabled using the EI instruction. When interrupt inputs I2, I3,
I4, and I5 are enabled, special internal relay are turned on, respectively. For details, refer to Chapter 16 "Interrupt
Control Instructions" in "SmartAXIS Ladder Programming Manual".
When the Touch starts operation, interrupt inputs are set to the interrupt allowed state.
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Notes for Using Interrupt Inputs and Timer Interrupt:
• When using an interrupt input or timer interrupt, separate the interrupt program from the main program using the
END instruction at the end of the main program.
• When an interrupt program calls another subroutine, a maximum of 3 subroutine calls can be nested. If more than
3 calls are nested, a ladder program execution error occurs.
• When using an interrupt input or timer interrupt, include the label number of the interrupt program to be executed
when an interrupt occurs. The label numbers stored in data registers D8033 through D8035, D8037, and D8038
specify the interrupt programs for interrupt inputs I2, I3, I4, and I5 and timer interrupt, respectively.
• When more than one interrupt input is turned on at the same time, interrupt program execution is given priority to
inputs I2, I3, I4 and I5, in that order. If an interrupt is initiated while another interrupt program is executed, the
subsequent interrupt program is executed after the prior interrupt is completed. Multiple interrupt programs cannot
be executed simultaneously.
• Make sure that the execution time of the interrupt program is shorter than interrupt intervals sufficiently.
• Interrupt programs cannot use some instructions. For details, refer to Chapter 12 “2.2 Instructions Reference” on
page 12-14.
Group 12345
External Input I0 I1 I2 I3 I4 I5
Interrupt input ––
Interrupt
input
Interrupt
input
Interrupt
input
Interrupt
input
Special Data Register
(Jump Destination Label No.)
– – D8033 D8035 D8037 D8038
Special Internal Relay
(Interrupt Input Status):
Read only
– – M8071 M8073 M8074 M8075

IDEC SmartAXIS Touch FT1A Series Specifications

General

Brand	IDEC
Model	SmartAXIS Touch FT1A Series
Category	Controller
Language	English