Axis Monitoring (A3); Overview Of Monitoring Functions; Running Monitoring; Contour Monitoring - Siemens SINUMERIK 808D Function Manual

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Axis monitoring (A3)

4.1

Overview of monitoring functions

Overview of monitoring functions
● Motion monitoring functions
–

Contour monitoring

– Position monitoring
– Standstill monitoring
– Clamping monitoring
– Speed setpoint monitoring
– Actual velocity monitoring
– Encoder monitoring functions
● Monitoring of static limits
– Limit switch monitoring
4.2

Running monitoring

4.2.1 Contour monitoring
Function
The principle on which the contour monitoring function works is the constant comparison of the measured actual position
value with that calculated from the NC position setpoint. For the precalculation of the following error, a model is used that
simulates the dynamics of the position control including feedforward control.
So that the monitoring function does not respond incorrectly on slight speed fluctuations (caused by changes of load) a
tolerance band is allowed for the max. contour deviation.
If the permissible actual value deviation entered in MD36400 CONTOUR_TOL (tolerance band contour monitoring) is
exceeded, an alarm is signaled and the axes are stopped.
Effectiveness
Contour monitoring is active for axes and position-controlled spindles.
Effect
If the contour deviation is too large, this has the following effect:
● Alarm 25050 "Contour monitoring" is triggered
● The axis/spindle is brought to a standstill via a speed setpoint ramp with rapid stop (with open position control loop).
The braking ramp time is set in MD36610 AX_EMERGENCY_STOP_TIME (braking ramp time for error states).
● If the axis/spindle is involved in interpolation with other axes/spindles, these are brought to a standstill with rapid stop
with following error reduction (position setpoint = 0).
Remedy
● Increase tolerance band of monitoring in MD36400
● The actual "servo gain factor" must correspond to the desired servo gain factor set via MD32200 POSCTRL_GAIN
(servo gain factor). With analog spindles: MD32260 RATED_VELO (rated motor speed) and MD32250 RATED_OUTVAL
(rated output voltage) must be checked.
● Check optimization of the speed controller
● Check smooth running of the axes
● Check machine data for traversing movements (feed override, acceleration, max. speeds, ... )
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Function Manual
01/2017