Toshiba PROSEC T1-16S PLC User's Manual - CTi Automation

6.6.2 Sub-program #1
6F3B0253
6. Programming Information
If the sub-program #1 is programmed, it is executed once at the beginning of the first
scan (before main program execution).
Therefore, the sub-program #1 can be used to set the initial value into the registers.
The sub-program #1 is called the initial program.
The figure below shows the first scan operation.
RUN mode
transition 1st scan 2nd scan
The end of the sub-program #1 is recognized by the END instruction.
6.6.3 Timer interrupt program
Scan
I/O Timer Sub#1 Main program Mode I/O Timer Main program
The timer interrupt is the highest priority task. It is executed cyclically with a user
specified interval, with suspending other operation.
The interrupt interval is set in the system information. (5 to 1000 ms, 5 ms units)
Timer interrupt
1 scan
1 scan
Timer interrupt
interval
Time
Time
1 scan
Timer interrupt
interval
1 scan
The end of the timer interrupt is recognized by the IRET instruction.
Basic Hardware and Function 95
CTi Automation - Phone: 800.894.0412 - Fax: 208.368.0415 - Web: www.ctiautomation.net - Email: info@ctiautomation.net