Siemens s7-200 SMART Interrupt instruction

S7-200 SMART series programmable controller ** has 38 interrupt sources (9 reserved), which are divided into three categories: communication interrupt, input/output (I/O) interrupt and timebase interrupt. The interrupt priority specified by S7-200 SMART is communication interrupt, I/O interrupt and timebase interrupt in descending order. Different interrupt events within each type of interrupt have different priorities.

Interrupt instructions mainly include the following types:

ATCH: Interrupt connection, connect to an interrupt event to call the program segment.

ENI: allows interrupts globally, opens interrupt handling.

DISI: disables interrupt globally and disallows the process of the interrupt service program, but the interrupt event is still queued.

DTCH: Interrupt separation, disconnects the association between the interrupt event number and the interrupt service routine, and disallows the interrupt event.

RETI: Conditional interrupt return from the interrupt service routine based on the conditions of the logical operation.

CLR_EVNT: clears the interrupt queue.