The PLC
108
Operating Manual XCA 1100 / XCA 1200
●
Version 12/17
8.3
System Variables
System variables provide information about the status of the system,
for example about forced variables, CPU performance, etc. These
variables have fixed memory addresses and can be used by the PLC
program to obtain the corresponding information.
All the system variables in the following table are already declared in
the
Global_Variables
area of the
Global_Variables
worksheet.
Name
Data type Log.
addr.
(byte)
Log.
addr.
(bit)
Description
PLCMODE_ON
BOOL
0
0
TRUE := current PLC state is ON
PLCMODE_RUN
BOOL
0
1
TRUE := current PLC state is RUN
PLCMODE_STOP
BOOL
0
2
TRUE := current PLC state is STOP
PLCMODE_HALT
BOOL
0
3
TRUE := current PLC state is HALT
PLCDEBUG_BPSET
BOOL
1
4
TRUE := one or more breakpoints have been
set
PLCDEBUG_FORCE
BOOL
2
0
TRUE := one or more variables have been
forced
PLCDEBUG_POWERFLOW
BOOL
2
3
TRUE := powerflow active
PLC_TICKS_PER_SEC
INT
44
-
Number of system ticks per second, used by
the PLC as the basis for the system time. This
value determines the time resolution of the
PLC for time delay function blocks like TON,
TOF and TP, and the shortest cycle time for
the DEFAULT task and cyclical tasks.
PLC_SYS_TICK_CNT
DINT
52
-
Number of counted PLC system ticks
Table 25: System variables
As well as these system variables, other variables are also defined,
containing information on the system. The type definitions of the
variables can be found in the
PLC_Types
section of the
"SchleicherLib" library.
