You can use forced refreshing for the following data types.
Boolean BOOL and SAFEBOOL
Bit string BYTE and WORD
Integers INT, SAFEINT, DINT, and SAFE-
DINT
Times of Day TIME and SAFETIME
Precautions for Safe Use
• With forced refreshing, the values of variables are overwritten with specified values and then
the safety programs are executed.
If forced refreshing is used for variables that give the results of program processing, the vari-
ables will first take the specified values, but they will then be overwritten by the safety pro-
gram.
• Depending on the dif
ference in the forced status, the control system may operate unexpect-
edly.
Precautions for Correct Use
• Forced status for forced refreshing is not removed when you change from DEBUG mode
(STOPPED) to DEBUG mode (RUN).
•
You can use forced refreshing for the following variables: device variables assigned to Safety
I/O Units and user-defined variables.
• Even if you use forced refreshing for the device variables assigned to the input terminal to a
Safety Input Unit, the forced value will not be applied to the variable that is assigned to the
I/O port of an NJ/NX-series CPU Unit.
l
Forced Refreshing of BOOL Variables in the FBD Editor
Use the following procedure to execute forced refreshing on BOOL variables.
1 Click the present value of the BOOL variable to change.
Example: To force-refresh variable a, click the present value of
FALSE.
The value changes to a temporary status.
A temporary value appears in <> on the right side of the present value. This indicates that the
temporary value is available for forced refreshing.
Temporary value is displayed
Each click toggles the temporary value.
7 Checking Operation and Actual Operation
7 - 35
NX-series Safety Control Unit User's Manual (Z930)
7-6 Functions for Checking Operation
7
7-6-5 Controlling BOOL Variables, Changing Present Values, and Using Forced Re-
freshing
To Next Page
Loading...
Need help?
General
