Delta DVP-ES2 - Manual (Page 85)

2 . P r o g r a m m i n g C o n c e p ts
Y0
X1
P2 CALL
X0
Y1
P**
20
P2
FEND
Y1
SRET
24
(subroutine
P2)
subroutine
Call subroutine P**
subroutine return
Interrupt pointer I: used with application instruction API 04 EI, API 05 DI, API 03 IRET. There are
four types of interruption pointers. To insert an interruption, users need to combine EI (enable
interruption), DI (disable interruption) and IRET (interruption return) instructions
1. External interrupt
„ When input signal of input terminal X0~X7 is triggered on rising-edge or falling-edge, it will
interrupt current program execution and jump to the designated interrupt subroutine pointer
I000/I001(X0), I100/I101(X1), I200/I201(X2), I300/I301(X3), I400/I401(X4), I500/I501(X5),
I600/I601(X6), I700/I701(X7). When IRET instruction is executed, program execution returns
to the address before interrupt occurs.
„ When X0 (C243) works with I100/I101 (X1), X0/X1 (C246, C248, C252) works with I400/I401,
the value of C243, C246, C248, C252 will be stored in (D1240, D1241)
„ When X2 (C244) works with I300/I301 (X3), X2/X3 (C250, C254) works with I500/I501, the
value of C244, C250, C254 will be stored in (D1242, D1243).
2. Timer interrupt
PLC automatically interrupts the currently executed program every a fixed period of time
(2ms~99ms) and jumps to the execution of a designated interruption subroutine
3. Counter interrupt
The high-speed counter comparison instruction API 53 DHSCS can designate that when the
comparison reaches the target, the currently executed program will be interrupted and jump to the
designated interruption subrountine executing the interruption pointers I010, I020, I030, I040,
I050 ,I060, I070, I080..
4. Communication interrupt
I140:
Communication instruction RS (COM1 RS-232) can be designated to send interrupt request when
specific charcters are received. Interrupt I140 and specific characters is set to low byte of D1167.
This function can be adopted when the PLC receives data of different length during the
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