Siemens SINUMERIK 840D sl Programming Manual page 409

Definition (DEF) of user variables: Limit values and implicit initialization values
If no explicit initialization value is defined when defining a user variable of one of the above data
types, the variable is set to the data type's implicit initialization value.
● INT: 0
● REAL: 0.0
● CHAR: 0
If the implicit initialization value is outside the definition range specified by the programmed limit
values, the variable is initialized with the limit value which is closest to the implicit initialization
value:
● Implicit initialization value < lower limit value (LLI) ⇒
● Implicit initialization value > upper limit value (ULI) ⇒
Examples:
Program code
DEF REAL GUD1
DEF REAL LLI 5.0 GUD2
DEF REAL ULI –5 GUD3
Redefinition (REDEF) of user variables: Limit values and current actual values
If the limit values of a user variable are redefined, they change to the extent that the current
actual value is outside the new definition range, an alarm will be issued and the limit values will
be rejected.
Note
Redefinition (REDEF) of user variables
If the limit values of a user variable are redefined, care must be taken to ensure that the
following values are changed consistently:
● Limit values
● Actual value
● Initialization value on redefinition and automatic reinitialization on the basis of INIPO, INIRE
or INICF
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
initialization value = lower limit value
initialization value = upper limit value
Comment
; Lower limit value = definition range limit
; Upper limit value = definition range limit
; No initialization value programmed
; => Implicit initialization value = 0.0
; Lower limit value = 5.0
; Upper limit value = definition range limit
; => Initialization value = 5.0
; Lower limit value = definition range limit
; Upper limit value = -5.0
; => Initialization value = -5.0
Work preparation
3.1 Flexible NC programming
409