Schleicher XCx 300, Operating Manual

Page: 92 / 180

The XCx Multi-Tasking System
92
Operating Manual XCx 300 / 500 / 540 Version 09/08
8.2.3 System tasks
System tasks and system programs (SPGs) are started automatically
by the operating system when an event occurs in connection with the
operating system.
The SPGs which can be used are listed in the following table:
No. Name Event Actions
SPG 0 WARM_START Is executed during a warm start

Retentive data is not initialized

Non-buffered data is initialized

The open function of the I/O driver
is executed

User tasks are activated

PLC switches to 'run' state
SPG 1 COLD_START Is executed during a cold start

All data is initialized

The open function of the I/O driver
is executed

User tasks are activated

PLC switches to 'run' state
SPG 2 TO_STOP Is executed when program
execution is stopped

User tasks are deactivated

All outputs are updated

The close function of the I/O driver
is executed

PLC switches to 'STOP' state
SPG 10 WATCHDOG Is executed when a task has
not been completed within its
watchdog time

User tasks are deactivated

All outputs are updated

The close function of the I/O driver
is executed

PLC switches to 'STOP' state
SPG 11 ZERODIV Is executed if division by zero
occurs during program
execution

User tasks are deactivated

All outputs are updated

The close function of the I/O driver
is executed

PLC switches to 'STOP' state
SPG 12 STACKOVER Is executed if a stackover has
occurred. Is only executed if the
'Stack-Prüfung' ['Stack check']
checkbox in the 'Ressource ...
einrichten' [Resource ... Set up]
dialog in MULTIPROG was
activated.

User tasks are deactivated

All outputs are updated

The close function of the I/O driver
is executed

PLC switches to 'STOP' state
SPG 13 BADCAL Is executed if a non-existent
manufacturer-specific POU is
called

User tasks are deactivated

All outputs are updated

The close function of the I/O driver
is executed

PLC switches to 'STOP' state
SPG 14 IOERROR Is executed if an error occurs in
the I/O driver while the process
is running

PLC continues execution
SPG 16 MATHERR Is executed if a sliding point
error occurs in an arithmetic
function

User tasks are deactivated

All outputs are updated

The close function of the I/O driver
is executed

PLC switches to 'STOP' state
SPG 17 CPU_OVERLOAD Is executed if a CPU overload
occurs

User tasks are deactivated

All outputs are updated

The close function of the I/O driver
is executed

PLC switches to 'STOP' state
SPG 18 INITIODRV_ERR Is executed if an error occurs in
I/O driver initialization during a

PLC does not start