Accessing the Values of System Variables

While running an application online, access diagnostic information from system variables for individual controllers, updated by the running code or simulation code. When running an application online, the cycle timing system variables are also available from the Cycle Timing
dialog box, accessed from the Online
menu.

System variables hold the values of information relating to cycle count, timing, kernel bindings, and controller information. Monitor system variables from the dictionary instances for resources. Read from and write to system variables. Available system variables are:

Variable name	Type	Read/Write	Description
__SYSVA_CYCLECNT	DINT	Read	Cycle counter
__SYSVA_CYCLEDATE	UDINT	Read	Timestamp of the beginning of the cycle in milliseconds
__SYSVA_KVBPERR	BOOL	Read/Write	Kernel variable binding producing error (production error)
__SYSVA_KVBCERR	BOOL	Read/Write	Kernel variable binding consuming error (consumption error)
__SYSVA_RESNAME	STRING	Read	Resource name (max length=255)
__SYSVA_SCANCNT	DINT	Read	Input scan counter
__SYSVA_TCYCYCTIME	TIME	Read/Write	Programmed cycle time. The defined cycle time for the controller.
__SYSVA_TCYCURRENT	TIME	Read	Current cycle time. The time spent with the virtual machine.
__SYSVA_TCYMAXIMUM	TIME	Read	Maximum cycle time. The longest period of time used for a current cycle (__SYSVA_TCYCURRENT), since connecting to the controller.
__SYSVA_TCYOVERFLOW	DINT	Read	Cycle overflow. The number of current cycles (__SYSVA_TCYCURRENT) that have exceeded the programmed cycle time.
__SYSVA_RESMODE	SINT	Read	Resource execution mode. Possible modes are: -5: Non-fatal error -4: Stopped in stepping mode after bound check exception -3: Stopped in stepping mode after division by zero exception -2: Stopped in stepping mode after exception -1: Fatal error 0: No resource available 1: Stored resource available NOT USED (CMG) 2: Ready to run 3: Running in real time 4: Running in cycle by cycle 5: Stopped from encountering an SFC breakpoint 7: Stopped while in stepping mode
__SYSVA_CCEXEC	BOOL	Write	Execute one cycle when application is in cycle to cycle mode
__SYSVA_TCYTRUECURRENT	TIME	Read	True cycle time. The real duration of a cycle.

To access the values of system variables in design mode

From a program organization unit (POU), right-click the required variable, and select Variable Monitoring
(or press Ctrl+I
).

To access the values of system variables in online or simulation mode

Create a spy list.

Open the Variable Selector
from a language editor.

Select the System Variables
tab.

Select all variables.

Right-click and select Add to
<name of created spy list>
.

Run the application online or simulate the application.

Open the created spy list.

Working with AADvance Applications

Spy Lists

Variable Selector

Run an Application Online

Simulate an application

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