Siemens SINUMERIK 840D sl Commissioning Manual page 698

Programming commands
6.2 Methods
6.2.1 CHANGE
Description
CHANGE methods are executed if a variable value changes, i.e., variable calculations that
are performed as soon as a variable value changes are configured within a CHANGE
method.
There are two types of CHANGE method, i.e., element-specific and global:
● The element-specific CHANGE method is executed if the value of a specified variable
changes. If a system or user variable is assigned to a variable, cyclic updating of the
variable value can be configured in a CHANGE method.
● The global CHANGE method is executed if the value of any variable changes and no
element-specific CHANGE method has been configured.
"Element-specific" programming
Syntax:
Description:
Parameters:
Example
DEF VAR1=(I//////"DB20.DBB1")
CHANGE(VAR1)
IF VAR1.Val <> 1
VAR1.st="Tool OK!"
ELSE
ENDIF
VAR2.Var=2
END_CHANGE
80
otto=1
VAR1.st="Attention: Error!"
otto=2
(Identifier)
CHANGE
...
END_CHANGE
Changes the value of a specific variable
Identifier Name of the variable
; A system variable is assigned to Var1
; If the value of the system variable ≠ 1, the
short text of the variable states: Tool OK!
; If the value of the system variable = 1, the
short text of the variable states: Attention:
Error!
Programming Manual, 03/2013, 6FC5397-1DP40-3BA1
SINUMERIK Integrate Run MyScreens (BE2)