Mitsubishi Electric MELSEC FX3U - Examples of Practical Program (Timer Interrupt Programs Using Applied Instruction)

863
FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
36 Interrupt Function and Pulse Catch Function
36.5 Timer Interrupt (Interrupt in Constant Cycle)
31
FNC275-FNC279 Data Transfer 3
32
FNC280-FNC289 High Speed Processing 2
33
FNC290-FNC299 Extension File Register
34
FNC300-FNC305 FX
3U
-CF-ADP
35
SFC•STL Programming
36
Interrupt Function
37
Special Device
38
Error Code
A
Version Up Information
B
Execution Times
5. Cautions
• Each pointer number (I6, I7 or I8) can be used only once.
• When M8056 to M8058 is set to ON in a program, a corresponding timer interrupt is disabled.
6. Program example
→ For program examples in which RAMP (FNC 67) or HKY (FNC 71) instructions are combined, refer
to Subsection 36.5.2.
In the program example shown below, data is added and the addition result is compared with the set value
every 10 ms.
1) Program example
36.5.2 Examples of practical program (timer interrupt programs using applied instruction)
RAMP (FNC 67), HKY (FNC 71), SEGL (FNC 74), ARWS (FNC 75) and PR (FNC 77) instructions execute a
series of operations in synchronization with the scan time.
Because the total time may be too long or time fluctuation may cause a problem in these instructions, it is
recommended to execute these instructions at a constant time interval using the timer interrupt function.
When not using the timer interrupt function, use the constant scan mode.
Step
0
I610
Interrupt
pointer
When interrupt is
given at every 10 ms
M3
X001
FNC 04
EI
FNC 06
FEND
FNC 24
INC
FNC224
LD=
FNC 03
IRET
END
SET M3
D0
K1000 D0 RST M3
Interrupts are enabled by EI instruction.
The main program is described.
When M3 is set to ON, FNC 24 (INC)
instruction becomes valid.
The main program is finished by FEND
instruction.
"1" is added to the current value of D0 at
every 10 ms.
When the current value of D0 reaches
"1000", M3 is reset.
The current value of D0 is ramp data
which changes from "0" to "1000" in 10
seconds.
In the program example using FNC 67
(RAMP) instruction shown later, the ramp
data is made using a dedicated applied
instruction.