LSIS Master-K K1000S - Page 36

Chapter 4 CPU modules MASTER-K
4-13
2) TDI (Time driven interrupt)
TDI occurs periodically with the constant interval assigned in parameter setting. The
interrupt routine of TDI starts with the TDINT instruction and ends with the IRET
instruction.
When multiple interrupt factors occur simultaneously, interrupt routines are executed
according to the priority given to the each interrupt. If an interrupt factor has higher priority
occurs while other interrupt of lower priority is executing, the interrupt routine of lower
priority will be stopped and the interrupt of higher priority will be executed first. Otherwise,
two interrupts are executed consequently.
The maximum numbers of TDI for K200S / 300S / 1000S are shown as following table.
PLC type Available TDI
K200S TDINT 0 ~ 7
K300S TDINT 0 ~ 13
K1000S TDINT 0 ~ 29
The following figure shows an example of TDI execution.
Used TDI
TDI 0 : occurs every 200ms
TDI 1 : occurs every 100ms
TDI 2 : occurs every 400ms
A B C A B A B CB B
100ms 100ms 100ms 100ms
200ms
400ms
200ms
Interrupt routines
A : The routine corresponding to TDI 0
B : The routine corresponding to TDI 1
C : The routine corresponding to TDI 2