Omron CPM1A operation manual Input Interrupts, PC model Input bits Response time

CPM1A Features and Functions		Section 1-1
Input Interrupts	The CPM1A-10CDR-j/10CDT-D/10CDT1-D PCs have 2 interrupt input termi-
	nals and the CPM1A-20CDR-j/20CDT-D/20CDT1-D, CPM1A-30CDR-j/
	30CDT-D/30CDT1-D, and CPM1A-40CDR-j/40CDT-D/40CDT1-D PCs have
	4 interrupt input terminals. There are two modes for input interrupts: input inter-
	rupt mode and counter mode.
1, 2, 3...	1. When an interrupt occurs in Input Interrupt Mode, the main program is inter-
	rupted and the interrupt program is executed immediately, regardless of the
	cycle time.

2.In Counter Mode, external input signals are counted at high speed (up to 1 kHz) and an interrupt is generated each time the count reaches the set value. When an interrupt occurs, the main program is interrupted and the interrupt program is executed. The set value can be set from 0 to 65,535.

The following diagram shows the program execution when an interrupt occurs.

Main program

MOV

ADD

Input interrupt

Interrupt program

SBN00

MOV

END

RET

PC model	Input bits	Response time
CPM1A-10CDR-j/10CDT-D/	IR 00003 to IR 00004	0.3 ms
10CDT1-D		(1 kHz in Counter Mode)
CPM1A-20CDR-j/20CDT-D/	IR 00003 to IR 00006
20CDT1-D/30CDR-j/
30CDT-D/30CDT1-D/
40CDR-j/40CDT-D/
40CDT1-D

Note When not using as interrupt input terminals, the input bits IR 00003 to IR 00006 can be used as normal input terminals.

!Caution Although IORF(97) can be used in interrupt subroutines, you must be careful of the interval between IORF(97) executions. If IORF(97) is executed too frequent- ly, a fatal system error may occur (FALS 9F), stopping operation. The interval between executions of IORF(97) should be at least 1.3 ms + total execution time of the interrupt subroutine.

6