Technical data

Table Of Contents
System Software for S7-300/400 System and Standard Functions - Volume 1/2
A5E00709327-01
10-1
10 SFCs for Handling Time-Delay Interrupts
10.1 Handling Time-Delay Interrupts
Definition
After you have called SFC 32 "SRT_DINT," the operating system generates an
interrupt after the specified delay time has elapsed, in other words, the selected
time-delay interrupt OB is called. This interrupt is known as a time-delay interrupt.
Conditions for the Call
Before a time-delay interrupt OB can be called by the operating system, the
following conditions must be met:
The time-delay interrupt OB must be started by SFC 32 "SRT_DINT."
The time-delay interrupt OB must not be deselected with STEP 7.
The time-delay interrupt OB must exist in the CPU.
Purpose of SFC 32 to SFC 34
The system functions SFC 32 to SFC 34 described in the following sections are
used as follows:
To start time-delay interrupts (SFC 32 "SRT_DINT")
To cancel time-delay interrupts (SFC 33 "CAN_DINT")
To query time-delay interrupts (SFC 34 "QRY_DINT").