Siemens SINUMERIK 840D Function Manual page 460

M3: Coupled axes
14.3 Master value coupling
System variables of the master value
The following master value system variables can only be read from part program and from
synchronous actions:
System variable
$AA_LEAD_V[ax]
$AA_LEAD_P[ax]
$AA_LEAD_P_TURN
The speeds and positions of simulated master values (when $SA_LEAD_TYPE[ax]=2) can be
written in and read from the part program and synchronous actions.
System variable
$AA_LEAD_SV[ax]
$AA_LEAD_SP[ax]
System variables of the following axis
For the following axis, the following system variables can be read in the part program and
synchronized action:
System variable
$AA_SYNC[ax]
$AA_IN_SYNC[ax]
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Meaning
Velocity of the leading axis
Position of the leading axis
Master value position
Portion that is deducted during modulo reaction.
The actual (not modulo-reduced) position of the leading axis is:
$AA_LEAD_P_TURN + $AA_LEAD_P
Meaning
Simulated master value velocity per IPO cycle
Simulated position in MCS
Meaning
Condition of the coupling between following and leading axes
Value Meaning
0 not synchronized
1 "Coarse synchronous operation"
2 "Fine synchronous operation"
3 "Coarse synchronous operation"
tion"
2)
Corresponds to:
1)
● MD37200 $MA_COUPLE_POS_TOL_COARSE
● DB31, ... DBX98.1 (coarse synchronous operation)
2)
● MD37210 $MA_COUPLE_POS_TOL_FINE
● DB31, ... DBX98.0 (fine synchronous operation)
Condition of the synchronization between following and leading axes
Value Meaning
0 Synchronization not started or ended.
1 Synchronization is running, i. e., the following axis is synchronized.
$AA_IN_SYNC[ax] corresponds to the NC/PLC interface signal:
DB31, ... DBX99.4 (synchronization running)
1)
2)
AND "Fine synchronous opera‐
1)
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA