Technical data

Table Of Contents
System Software for S7-300/400 System and Standard Functions - Volume 1/2
A5E00709327-01
9-1
9 SFCs for Handling Time-of-Day Interrupts
9.1 Handling Time-of-Day Interrupts
Definition
A time-of-day interrupt results in one of the time-of-day interrupt OBs (OB10 to
OB 17) being called.
Conditions for the Call
Before a time-of-day interrupt OB can be called by the operating system, the
following conditions must be met:
The time-of-day interrupt OB must have parameters assigned to it (start date
and time, execution) using either
- STEP 7 or
- SFC 28 "SET_TINT" in the user program.
The time-of-day interrupt OB must be activated using
- STEP 7 or
- SFC 30 "ACT_TINT" in the user program.
The time-of-day interrupt OB must not be deselected with STEP 7.
The time-of-day interrupt OB must exist in the CPU.
If you set the interrupt with SFC 30 "ACT_TINT" and if you have specified the
execution of the OB as once only, the start date and time must not yet have
passed. If you have selected periodic execution, the time-of-day interrupt OB
will be called when the next period is completed (start time + multiple of the
specified period).
Hint
You can assign parameters to the time-of-day interrupt using STEP 7 and then
activate the interrupt in your user program (SFC 30 "ACT_TINT").
Purpose of SFC 28 to SFC 31
The system functions SFC 28 to SFC 31 described in the following sections are
used as follows:
To set time-of-day interrupts (SFC 28 "SET_TINT")
To cancel time-of-day interrupts (SFC 29 "CAN_TINT")
To activate time-of-day interrupts (SFC 30 "ACT_TINT")
To query time-of-day interrupts (SFC 31 "QRY_TINT")