System Variables - Siemens SINUMERIK 840DE sl Function Manual

Tool data
A tool is always assigned the first transformation of chained transformations. The subsequent
transformation then behaves as if the active tool length were zero.
Only the basic tool lengths set in the machine data (_BASE_TOOL_) are valid for the first
transformation in the chain.
2.4.1.2

System variables

The following transformation-specific system variables are available:
System variable
$AA_ITR
$AA_IBC
$VA_ITR
$VA_IBC
$VA_IW
$VA_IB
Boundary conditions
● Warm restart
The encoder position has the value 0 for non-referenced axes. For the $VA variables, the
encoder actual values are appropriately inverse-transformed.
● Channel reset
The active transformation can change after a channel reset. This can have a direct influence
on the system variable values.
An active transformation, which is active again after a channel reset, is briefly deactivated
and then reactivated. This influences the position variables. The values of variables can
change.
Via the variable:
$AC_STAT == 0
this status can be queried in synchronous actions.
Transformations
Function Manual, 06/2019, A5E47435470B AA
Meaning
Current setpoint value at output of the nth transformation
Current setpoint value of a cartesian axis
Current actual value at output of the nth transformation
Current cartesian BCS encoder position of an axis
Current WCS actual value of an axis
Current BCS encoder position of an axis
M1: Kinematics transformation
2.4 Chained transformations
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