7.5 User Program
The user program is stored by each program types as shown in the following diagram and is managed by units called blocks in each program types.
User program configuration | Program type internal configuration |
(Program types) | (Blocks) |
Main program
Timer interrupt
I/O interrupt #1
I/O interrupt #2
Subroutine
Block 1
Block 2
Block 10
Block N
(N = max. 256)
Block 1
In the user program, the main program is the core. The scan operation explained is for the main program. The operation of other program types are explained in the following sections:
The following 6 program types are supported by the V200 .
(1)……..Main program
(2)
(3)Timer interrupt program
(4)I/O interrupt program #1
(5)I/O interrupt program #2
(6)Subroutine
The blocks are just separators of the program, and have no effect on the program execution. However, by dividing the user program into some blocks, the program becomes easy to understand. The block numbers need not be con- seductive. In each program type and block, there is no limit of program capacity. The only limit is the total capacity.
7.5.1 Main Program
The main program is the core of the user program. It is executed once in each scan.
1 scan time
Mode I/O Timer | Main program |
Time
Mode I/O Timer | Main program |
In the above figure,
Mode means the mode control operation I/O means the I/O update processing Timer means the timer up date processing
Main program means the main program execution
the
The end of the main program is recognized by the END instruction. Although instructions may be present after the END instruction, that portion will not be executed.
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