Special Features Of Synchronous Mode; Special Features Of Synchronous Mode In General - Siemens SINUMERIK 840D sl Function Manual

14.4

Special features of synchronous mode

14.4
14.4.1

Special features of synchronous mode in general

Control dynamics
When using the setpoint coupling, the position control parameters of FS and LS (e.g. K
factor) should be matched with one another. If necessary, different parameter blocks should
be activated for speed control and synchronized mode. As a variance from position control,
feedforward control and parameter block, the control parameters of the following spindle can
also be set as they would be for an uncoupled scenario using MD30455
$MA_MISC_FUNCTION_MASK, see Section "Special points regarding start-up of a
synchronous spindle coupling".
Feedforward control
Due to the improved control system dynamic response it provides, feedforward control for
the following and leading spindles in synchronous mode is always active.
It can, however, be deselected for FS and LS with axis-specific MD32620
$MA_FFW_MODE. If MD32620 $MA_FFW_MODE is set to zero, there are function
limitations. Position control can no longer be activated in motion with SPCON. SPOS, M19 or
SPOSA are therefore not possible. The NC parts program cannot deactivate the feedforward
control for LS and FS with FFWOF.
The feedforward control mode (speed or torque feedforward control) is defined in axis-
specific MD32620 $MA_FFW_MODE.
References:
/FB2/ Function Manual, Extended Functions, Compensations (K3)
Speed and acceleration limits
The speed and acceleration limits of the spindles operating in synchronous mode are
determined by the "weakest" spindle in the synchronous spindle pair. The current gear
stages, the programmed acceleration and, for the leading spindle, the effective position
control status (On/Off) are taken into account for this purpose.
The maximum speed of the leading spindle is calculated internally in the control taking into
account the speed ratio and the spindle limitations of the following spindle.
Multiple couplings
If the system detects that a coupling is already active for an FS and LS when synchronous
mode is activated, then the activation process is ignored and an alarm message is
generated.
Example of multiple couplings:
● A spindle is acting as the FS for several LS.
● Coupling cascade
Extended Functions
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
S3: Synchronous spindle
14.4 Special features of synchronous mode
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