Siemens SINUMERIK 840D Function Manual page 857

Determine current coupling status
The $AA_COUP_ACT[<axial expression>] axial system variable can be used in the NC part
program to specify the current coupling status for the specified axis/spindle (see Section "Axial
system variables for synchronous spindle (Page 869)"). As soon as the synchronous spindle
coupling is active for the following spindle, bit 2 must be "1" when read.
Change defined angular offset
Language commands COUPON and SPOS allow the defined angular offset to be changed while
synchronous mode is active. The following spindle is positioned as an overlaid movement at the
angular offset programmed with POS
DBX98.4) is set.
Angular offset POS
FS
The defined angular offset POS
degrees position of the leading spindle in a positive direction of rotation.
The "0° position" of a position-controlled spindle is calculated as follows:
● From the zero mark or proximity sensor signal of the measurement system and
● From the reference values saved using axis-specific machine data:
MD34100 $MA_REFP_SET_POS, reference point value,
of no significance with interval-coded systems.
MD34080 $MA_REFP_MOVE_DIST reference point distance/target point
with interval-coded systems,
MD34090 $MA_REFP_MOVE_DIST_CORR reference point offset / absolute offset with
interval coding.
Range of POS
Further information
R1: Referencing (Page 291)
Read current angular offset
Using axial system variables, it is possible to read the current position offset between the FS
and LS in the NC part program. A distinction is made between:
● Current position offset of setpoint between FS and LS
$AA_COUP_OFFS [<axis name for FS>]
● Current position offset of actual value between FS and LS
$VA_COUP_OFFS [<axis name for FS>]
(Explanation of <axis name>, see Section "Synchronous mode (Page 849)")
Activation after power ON
Synchronous mode can also be activated with non-referenced/synchronized FS or LS (IS
"Referenced/synchronized 1 or 2" DB31, ... DBX60.4 or DBX60.5 = 0). In this case, a warning
message is displayed.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
FS
must be specified as an absolute position referred to the zero
FS
: 0 ... 359.999°.
FS
. During this time, the IS "overlaid movement" (DB31, ...
S3: Synchronous spindle
19.1 Brief description
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