Siemens SINUMERIK 840C Installation Instructions Manual page 682

09.95
10.94
The decay time is not adapted when a value of 0 or of less than or equal to the
value in NC-MD 12360 is entered in NC-MD 13640.
Monitoring of the decay time continues to ensure that it cannot become a nega-
tive value at maximum acceleration (100 % of acceleration in diagram below). In
this case, the characteristic is positioned such that a decay time of 0 is calculated
at maximum acceleration.
Fig. 9.33
Parameterizing the While the neuronal network is in its learning phase, the error measuring time
error measuring time determines the time window during which the contour error is monitored after the
speed zero crossing.
Experience shows that the error measuring time for medium-range acceleration
rates (approx. 2 – 50 mm/s
the decay time.
The error measuring time must be adapted for the very high or very low accelera-
tion ranges. The time is adapted automatically according to the characteristic in
the diagram below. In this case, a value corresponding to 6 times the decay time
is set for the error measuring time at low acceleration rates tM1 while double the
decay time is set for high acceleration rates tM3 (default setting by the appro-
priate machine data).
In order to maintain these relationships when the decay time is changed, the er-
ror measuring times (e.g. 1st axis: NC-MD 13720, NC-MD 13760 and NC-MD
13800) are specified as a %age of the compensation time constant (NC-MD
12360).
If NC-MD 12360 is set to 0, then the percentages specified in NC-MDs 13720,
13760 and 13800 are referred to a time of 10 ms.
Fig. 9.34
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SINUMERIK 840C (IA)
9.5.4 Neural quadrant error compensation (QEC – SW 4)
Decay time
MD 13640
MD 12360
50%
2
) must be set to a value corresponding to three times
Measurement time
t
M1
(MD 13720)
t
M2
(MD 13760)
t
M3
(MD 13800)
1 2
a
1
9 Drive Servo Start-Up Application (as from SW 3)
Setpoint acceleration
100%
3 IAccelerationI
a a
2 3
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