Siemens SINUMERIK 840D sl Programming Manual page 402

Path traversing behavior
9.4 Axial leading value coupling (LEADON, LEADOF)
Create master value
As an option, master values can be generated with other self-programmed methods. The
master values generated in this way are written to and read from variables
- $AA_LEAD_SP
- $AA_LEAD_SV
Before you use these variables, the setting data $SA_LEAD_TYPE = 2 must be set.
Status of coupling
You can query the status of the coupling in the NC program with the following system
variable:
$AA_COUP_ACT[[axis]]
0: No coupling active
16: Master value coupling active
Status management for synchronized actions
Switching and coupling events are managed via real-time variables:
$AC_MARKER[i] = n
managed with:
i flag number
n status value
9-36
Master value position
Master value velocity
Programming Manual, 03/2006 Edition, 6FC5398-2BP10-1BA0
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