Technical data

SFCs for Diagnostics
System Software for S7-300/400 System and Standard Functions - Volume 1/2
13-2 A5E00709327-01
TOP_SI and START_UP_SI
The output parameters TOP_SI and START_UP_SI are two structures with
identical elements (see following table).
Structure Element Data Type Description
EV_CLASS BYTE • Bits 0 to 3: Event ID
• Bits 4 to 7: Event class
EV_NUM BYTE Event number
PRIORITY BYTE Number of the priority class (meaning of B#16#FE: OB
not available or locked or cannot be started in current
operating mode)
NUM BYTE OB number
TYP2_3 BYTE Data ID 2_3: identifies the information entered in ZI2_3
TYP1 BYTE Data ID 1: identifies the information entered in ZI1
ZI1 WORD Additional information 1
ZI2_3 DWORD Additional information 2_3
Note
The structure elements listed in the table and temporary variables of an OB have
an identical content.
Please note that temporary variables of the individual OBs could however have
different names and different data types. Also note that the call interface of each
OB includes additional information which is the date and the time of the OB
request.
Bits 4 to 7 of the EV_CLASS structure element contain the event class. The
following values are possible here:
• 1: Start events from standard OBs
• 2: Start events from synchronous error OBs
• 3: Start events from asynchronous error OBs
The PRIORITY structure element supplies the priority class belonging to the
current OB.
Apart from these two elements, NUM is also relevant. NUM contains the number of
the current OB or the startup OB that was started last.