HEIDENHAIN TNC 426 CB, Technical Manual

Page: 491 / 1135

December 2001 Monitoring Functions 6 – 161
6.11.3 Movement Monitoring
Movement monitoring is possible during operation both with velocity
feedforward and with following error.
During movement monitoring, the actual path traveled is compared at short
intervals (several servo cycles) with the nominal path calculated by the NC. If
during this period the actual path traveled differs from the calculated path, the
flashing error message
MOVEMENT MONITORING IN <AXIS>
appears.
Analog axes:
An existing offset during a standstill may cause a potential at the analog output
without any resulting positioning movement:
7 7 7 7 In MP1140.x, enter a threshold from which the movement monitoring
should go into effect.
Digital axes:
There is no offset.
7 7 7 7 Enter a minimum value in MP1140.x.
For digital axes, in addition to the comparison of actual and nominal values, the
calculated position from the pulses of the position encoder are compared with
the pulses of the speed encoder:
7 7 7 7 Enter in MP332.x the number of signal periods and in MP331.x the path for
the number of signal periods ((See “Encoders” on page 6 – 8)).
7 7 7 7 Enter the distance per motor revolution in MP2020.x. A formula can also be
entered in MP2020.x (See “Special case: Entering a formula (As of NC
software 280 472-01)” on page 4 – 5).
7 7 7 7 In MP2800.x, enter a limit value for this position difference. If you are not
using a position encoder, you must enter 0 in MP2800.x as the position
difference.
If the difference is greater than the input value from MP2800.x, the error
message
MOVEMENT MONITORING IN <AXIS> B
appears.
MP1140.0-8 Threshold from which movement monitoring is effective
for axes 1 to 9
Input: Analog axes: 0.030 to 10.000 [V]
Digital axes: 0.030 to 10.000 [1000 rpm]
recommended: 0.030 [1000 rpm]
MP2020.0-8 Traverse per motor revolution for axes 1 to 9
Input: Analog axes: nonfunctional
Digital axes: 0 to 100.000 [mm] or [°]
MP2800.0-8 Movement monitoring for position and speed
for axes 1 to 9
Input: Analog axes: nonfunctional
Digital axes: 0 to 99 999.999 [mm]
0: No monitoring
Warning
If you enter the maximum value in MP1140.x or MP2800.x, no movement
monitoring is active.
Safe machine operation is not possible without the movement monitoring
function.