HEIDENHAIN TNC 122 Technical Manual - Manual (Page 30)

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TNC 122 9 Machine Integration 29
9.5 Monitoring Functions
The NC monitors the axis positions and the dynamic behavior of the machine. If the fixed values in
the machine parameters are exceeded, an error message is displayed and the machine is stopped.
Position, standstill and movement are monitored.
Position monitoring
Machine parameters MP1720.x determine the range for the continuous position monitoring of the
machine (servo lag monitoring). Monitoring goes into effect as soon as the axes are under control of
the position control loop. If the limits in MP1720 are exceeded, the following blinking error message
appears:
POS. ERROR A <axis>
The control must be switched off to correct this error. Realistic input values are approximately 1 to
1.4 times the servo lag at rapid traverse.
MP1720
Position monitoring
Input range: 0.001 to 200.000 [mm]
Movement monitoring
At short intervals (several control cycles) the path actually traversed is compared with the nominal
path as calculated by the NC. If the path traversed during this interval deviates from the calculated
path, the following blinking error message will appear:
POS. ERROR C <axis>
Movement monitoring is not active below the voltage entered in machine parameter MP1140.
If 12 [V] is entered in this machine parameter, no movement monitoring will be in effect.
It is not possible to safely operate the machine without movement monitoring.
MP1140
Movement monitoring
Input range: 0.03 to 12.00 [V]
Standstill monitoring
This monitoring goes into effect when the axes have reached the positioning window. The range
within which the axes may move is defined in MP1110. As soon as the position deviation is larger
than the value in MP1110, the following blinking error message is displayed:
POS.ERROR D <axis>
The message will also appear during approach to a target position if an overshoot is larger than the
value entered in MP1110, or if the axis moves in the opposite direction at the beginning of a
positioning move.
MP1110
Standstill monitoring
Entry range: 0.001 to 30.000 [mm]
Positioning window
The positioning window defines the range within which the control considers a position to have
been reached. When the position has been reached, the control starts the execution of the next
block. The size of the positioning window is defined in MP1030.x.