6 Assi
nin
Parameters to the Control and the PLC Pro
ram
6
03.96
6.9 Axes and spindles
6-146
Siemens AG 2000 All Rights Reserved
SINUMERIK 840D Installation and Start-Up Guide (IAD) – 04.00 Edition
S To absolute position (0 – 360 degrees)
S Incremental position (+/– 999999.99 degrees)
S Block change when position reached
S Block change on block end criterion
The control brakes the spindle down to creep speed at the acceleration rate for
speed operation. If the creep speed has been reached (INT “Spindle in setpoint
range”), the control branches into position control mode and the acceleration
rate for position control mode and the K
V
factor become active. The interface
signal “Fine exact stop” is output to indicate that the programmed position has
been reached (block change when position reached). The acceleration rate for
position control mode must be set such that the current limit is not reached. The
acceleration rate must be entered separately for each gear stage. If the spindle
is positioned from zero speed, it is accelerated up to a maximum speed corre-
sponding to creep speed; the direction is defined via machine data. The contour
monitoring function is activated as soon as the control mode switches to posi-
tion control.
MD 35300: SPIND_POSCTRL_VELO (creep speed)
MD 35350: SPIND_POSITIONING_DIR
(direction of rotation on positioning from zero speed)
MD 35210: GEAR_STEP_POSCTRL_ACCEL
(acceleration in position control mode)
MD 36000: STOP_LIMIT_COARSE (coarse exact stop )
MD 36010: STOP_LIMIT_FINE (fine exact stop)
MD 32200: POSCTRL_GAIN (K
V
factor)
MD 36400: CONTOUR_TOL (contour monitoring)
IS “Position reached with fine/coarse exact stop” (DB31, ... DBX60.6/60.7)
IS “Positioning mode” (DB31, ... DBX84.5)
6.9.18 Spindle synchronization
The spindle must match its position with the measuring system. This operation
is called “synchronization”. Synchronization always follows the zero mark of the
encoder or a Bero signal that is connected with the drive module of the SIMO-
DRIVE 611D. In MD 34200 ENC_REFP_MODE you set via which signal syn-
chronization is to be performed (zero mark (0) or Bero (1))
S After switch-on of the control if the spindle is moved with a programming
command.
S The signal “Resynchronize spindle 1/2” cancels the signal “Referenced/syn-
chronized 1/2”. The spindle resynchronizes with the next reference signal.
S After every gear stage changeover (MD 31040: ENC_IS_DIRECT=0)
S The spindle goes out of synchronism if a speed above the encoder limit fre-
quency is programmed. When the speed drops to below the encoder limit
frequency, the spindle is re-synchronized. If the synchronized state has
been lost, it is impossible to implement functions such as rotational feed-
rate, constant cutting velocity, tapping with and without compensating chuck,
positioning and axis modes.
Functionality
Machine data and
interface signals
When
synchronization is
necessary?
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